Audi Workshop Service and Repair Manuals

Fault table as of fault code “01044”

Indicated on vehicle diagnostic, testing and information system -VAS 5051A- and output on printer			Possible cause of trouble	Fault rectification
01044 Control unit incorrectly coded
			t  Control unit in dash panel insert -J285- not encoded in specified manner t  Fault on convenience data bus system t  Operating and display unit, Climatronic control unit -J255- not encoded in specified manner.	–  Check encoding transmitted to operating and display unit, Climatronic control unit -J255- (Reading measured value block, display group “019”) → Chapter –  Check encoding of control unit in dash panel insert -J285- and encode as specified if necessary → "Guided fault-finding" function of vehicle diagnostic, testing and information system VAS 5051 and → Electrical system; Rep. Gr. 01 –  Interrogate fault memories of all control units connected to convenience data bus system and locate and eliminate the data bus system faults displayed → "Guided fault-finding" function of vehicle diagnostic, testing and information system VAS 5051 and → Electrical system; Rep. Gr.01 –  Check encoding of operating and display unit, Climatronic control unit -J255- → Chapter (encoding for specific equipment).

Indicated on vehicle diagnostic, testing and information system -VAS 5051A- and output on printer			Possible cause of trouble	Fault rectification
01087 Basic setting not performed
			t  During the “Basic setting” function a fault has occurred or the ignition was switched off and the operating and display unit, Climatronic control unit -J255- was not able to conclude the function. t  Basic setting not performed following replacement of operating and display unit, Climatronic control unit -J255-. t  Basic setting performed with a non-encoded or incorrectly encoded operating and display unit, Climatronic control unit -J255-	–  Perform basic setting of operating and display unit, Climatronic control unit -J255- → Chapter. –  Check encoding transmitted by way of the convenience data bus system to the operating and display unit, Climatronic control unit -J255- (reading measured value block, display group “019”) → Chapter and then perform basic setting of operating and display unit, Climatronic control unit -J255- → Chapter.

Note The operating and display unit, Climatronic control unit -J255- switches automatically to “Econ” mode if basic setting was not performed after installing a new operating and display unit, Climatronic control unit -J255-.

Indicated on vehicle diagnostic, testing and information system -VAS 5051A- and output on printer			Possible cause of trouble	Fault rectification
01171 Front passenger seat temperature sensor -G60-
	t  Short to earth / SP t  Open circuit / short to positive / SP		t  Open circuit in heated front passenger seat cushion or in wiring between front passenger seat temperature sensor -G60- and operating and display unit, Climatronic control unit -J255-	–  Use current flow diagram to locate and eliminate open circuit –  Check front passenger seat temperature sensor -G60- and corresponding wiring → Chapter
01172 Driver seat temperature sensor -G59-
	t  Short to earth / SP t  Open circuit / short to positive / SP		t  Open circuit in heated driver seat cushion or in wiring between driver seat temperature sensor -G59- and operating and display unit, Climatronic control unit -J255-	–  Use current flow diagram to locate and eliminate open circuit –  Check driver seat temperature sensor -G59- and corresponding wiring → Chapter

Indicated on vehicle diagnostic, testing and information system -VAS 5051A- and output on printer			Possible cause of trouble	Fault rectification
01206 Ignition off time period signal
	t  Implausible signal / SP		t  Following connection of battery -A-, control unit in dash panel insert -J285- effected re-start (reset) and was therefore not able to transmit a time signal	–  Start engine and allow to run for 30 seconds –  Switch off engine –  Switch on ignition –  Interrogate and erase fault memory of operating and display unit, Climatronic control unit -J255- –  Check time signal from control unit in dash panel insert -J285- (Reading measured value block, display group “018”) → Chapter.
			t  Fault in control unit in dash panel insert -J285-	–  Interrogate fault memory of control unit in dash panel insert -J285- → "Guided fault-finding" function of vehicle diagnostic, testing and information system VAS 5051 and → Electrical system; Rep. Gr.01

Note If “ignition off time period signal” is not detected by the operating and display unit, Climatronic control unit -J255- when the ignition is switched on (transmitted by control unit in dash panel insert -J285- via convenience data bus system), the operating and display unit, Climatronic control unit -J255- assumes a standing time of more than 4 hours and the engine temperature is taken to be the same as the ambient temperature. In heating mode, this can lead to delayed start-up of the fresh-air blower -V2- despite the engine being warm. The ambient temperature indicator -G106- in the dash panel insert may also display incorrect ambient temperature values.

Indicated on vehicle diagnostic, testing and information system -VAS 5051A- and output on printer			Possible cause of trouble	Fault rectification
01207 Auxiliary heater control unit -J364-
	t  No communication / SP		t  Control unit in dash panel insert -J285- incorrectly encoded (incorrect adaption for auxiliary heater in adaption channel “018” in control unit in dash panel insert -J285-).	–  Check encoding transmitted to operating and display unit, Climatronic control unit -J255- (Reading measured value block, display group “019”) → Chapter. –  Check encoding and adaption of control unit in dash panel insert -J285- and then perform basic setting of operating and display unit, Climatronic control unit -J255- → "Guided fault-finding" function of vehicle diagnostic, testing and information system VAS 5051 and → Electrical system; Rep. Gr.01
			t  Interruption of power supply to auxiliary heater (to auxiliary heater control unit -J364-) with ignition switched on. t  Fault affecting data output has occurred in auxiliary heater control unit -J364-. t  No data telegram transmitted by auxiliary heater control unit -J364-.	–  Use current flow diagram to check and repair power supply to auxiliary heater (watch out for possible loose contact). –  Interrogate auxiliary heater fault memory. → Auxiliary heater; Rep. Gr.01 –  Check convenience data bus system → Chapter.
Continued in next table

Indicated on vehicle diagnostic, testing and information system -VAS 5051A- and output on printer			Possible cause of trouble	Fault rectification
01207 (continued)
			t  Open circuit in both signal wires (convenience data bus system) between auxiliary heater control unit -J364- and operating and display unit, Climatronic control unit -J255- t  No data telegram transmitted by auxiliary heater control unit -J364-. t  The operating and display unit, Climatronic control unit -J255- cannot read the data telegram transmitted by the auxiliary heater control unit -J364-.	–  Use current flow diagram to locate and eliminate open circuit or loose contact at both signal wires (convenience data bus system) between auxiliary heater control unit -J364- and operating and display unit, Climatronic control unit -J255- –  Check convenience data bus system → Chapter. –  Check part number of auxiliary heater control unit -J364- and operating and display unit, Climatronic control unit -J255-; the two control units must have been mutually released → Parts List

Note t  This fault is entered if the control unit in dash panel insert -J285- has been encoded for a vehicle with auxiliary heater (adaption in channel “018”) and there is no genuine Audi auxiliary heater installed. The control unit in dash panel insert -J285- informs the operating and display unit, Climatronic control unit -J255- that an auxiliary heater is fitted. The operating and display unit, Climatronic control unit -J255- thus expects information from the auxiliary heater control unit -J364- and does not receive this. t  The auxiliary heater control unit -J364- and the operating and display unit, Climatronic control unit -J255- cannot communicate if they do not operate on the same data level. t  Only genuine Audi auxiliary/supplementary heaters can be actuated by way of the convenience data bus system and exchange data with the other control units linked to this bus system. t  The majority of commercially available auxiliary heaters cannot exchange data via the convenience data bus system. Such auxiliary heaters are not to be connected to the convenience data bus system.

Indicated on vehicle diagnostic, testing and information system -VAS 5051A- and output on printer			Possible cause of trouble	Fault rectification
01229 Air conditioning system humidity sender -G260-
	t  Open circuit / short to positive / SP		t  Incorrect version of operating and display unit, Climatronic control unit -J255-.	–  Check part number and index of operating and display unit, Climatronic control unit -J255- → Parts List
	t  Open circuit / short to positive / SP t  Short to earth / SP		t  Short circuit, open circuit in wiring or incorrectly assigned connectors between air conditioning system humidity sender -G260- and operating and display unit, Climatronic control unit -J255- t  Open circuit in power supply or earth connection to air conditioning system humidity sender -G260- t  Air conditioning system humidity sender -G260- defective	–  Use current flow diagram to locate and eliminate short (to earth or positive), open circuit in wiring or incorrectly assigned connectors between air conditioning system humidity sender -G260- and operating and display unit, Climatronic control unit -J255- –  Use current flow diagram to locate and eliminate open circuit. –  Replace air conditioning system humidity sender -G260-

Note The installation of an air conditioning system humidity sender -G260- is not scheduled at present (date of introduction not yet finalised). This fault is displayed if a vehicle with no air conditioning system humidity sender -G260- has been fitted with an operating and display unit, Climatronic control unit -J255- for vehicles with air conditioning system humidity sender -G260- (not provided at present, date of introduction not yet finalised).

Indicated on vehicle diagnostic, testing and information system -VAS 5051A- and output on printer			Possible cause of trouble	Fault rectification
01230 Left footwell vent temperature sender -G261-
	t  Short to earth / SP t  Open circuit / short to positive / SP		t  Short circuit or open circuit in wiring between left footwell vent temperature sender -G261- and operating and display unit, Climatronic control unit -J255- t  Left footwell vent temperature sender -G261- defective	–  Use current flow diagram to locate and eliminate short circuit or open circuit in wiring –  Check left footwell vent temperature sender -G261- → Chapter
01231 Right footwell vent temperature sender -G262-
	t  Short to earth / SP t  Open circuit / short to positive / SP		t  Short circuit or open circuit in wiring between right footwell vent temperature sender -G262- and operating and display unit, Climatronic control unit -J255- t  Right footwell vent temperature sender -G262- defective	–  Use current flow diagram to locate and eliminate short circuit or open circuit in wiring –  Check right footwell vent temperature sender -G262- → Chapter

Indicated on vehicle diagnostic, testing and information system -VAS 5051A- and output on printer			Possible cause of trouble	Fault rectification
01232 Air conditioning system compressor regulating valve -N280-
	t  Short to earth / SP t  Short to positive / SP t  Open circuit / SP		t  Short circuit or open circuit in wiring between air conditioning system compressor regulating valve -N280- and operating and display unit, Climatronic control unit -J255- t  Open circuit in earth connection to air conditioning system compressor regulating valve -N280-	–  Use current flow diagram to locate and eliminate short circuit or open circuit in wiring
			t  Air conditioning system compressor regulating valve -N280- defective	–  Check air conditioning system compressor regulating valve -N280- → Chapter and (Reading measured value block, display group “001”) → Chapter

Note The air conditioning system compressor regulating valve -N280- is installed in the compressor (the compressor can only be replaced at a specialist air conditioner workshop). → Air conditioner with refrigerant R134a

Indicated on vehicle diagnostic, testing and information system -VAS 5051A- and output on printer			Possible cause of trouble	Fault rectification
01272 Central flap control motor -V70-
	t  Blocked or deenergised / SP		t  Short circuit, open circuit in wiring or wiring fault between central flap control motor -V70- and operating and display unit, Climatronic control unit -J255-	–  Use current flow diagram to locate and eliminate short circuit, open circuit in wiring or wiring fault
			t  Central flap stiff	–  Check freedom of movement of central flap
			t  Central flap control motor -V70- defective	–  Check central flap control motor -V70- → Chapter

Note In the case of an operating and display unit, Climatronic control unit -J255- up to hardware/software version “0203”, the type of fault “Short to earth” or “Open circuit/short to positive” may also be displayed for this control motor. The cause of the trouble with these operating and display units, Climatronic control unit -J255- is the same as for the fault “Blocked or deenergised”.

Indicated on vehicle diagnostic, testing and information system -VAS 5051A- and output on printer			Possible cause of trouble	Fault rectification
01273 Fresh air blower -V2-
	t  Blocked or deenergised / SP –  Duty cycle transmitted 55 ...64 %		t  Fresh air blower -V2- blocked, e.g. by foreign matter t  Fresh air blower -V2- defective	–  Remove fresh air blower -V2- and check for foreign matter –  Replace fresh air blower -V2-
	t  Defective –  Duty cycle transmitted 15...24% or 65...74%		t  Fresh air blower control unit -J126- in fresh air blower -V2- defective	–  Replace fresh air blower -V2-
	t  Short to earth / SP t  Open circuit / short to positive / SP		t  Short circuit or open circuit in wiring between fresh air blower -V2- (or to fresh air blower control unit -J126-) and operating and display unit, Climatronic control unit -J255- t  Open circuit in power supply or earth connection to fresh air blower -V2- (or to fresh air blower control unit -J126-).	–  Use current flow diagram to locate and eliminate short circuit or open circuit in wiring –  Use current flow diagram to locate and eliminate open circuit
Continued in next table

Indicated on vehicle diagnostic, testing and information system -VAS 5051A- and output on printer			Possible cause of trouble	Fault rectification
01273 (continued)
	t  Signal outside tolerance / SP –  Duty cycle transmitted 75...84%		t  Loose contact (short circuit, open circuit in wiring) or contact resistance between fresh air blower -V2- (or to fresh air blower control unit -J126-) and operating and display unit, Climatronic control unit -J255- t  Problems with actuation of fresh air blower -V2- by operating and display unit, Climatronic control unit -J255-. t  Fresh air blower -V2- defective	–  Use current flow diagram to locate and eliminate short circuit, open circuit in wiring or wiring fault. –  Replace operating and display unit, Climatronic control unit -J255-. –  Replace fresh air blower -V2-
	t  Power supply too low / SP –  Duty cycle transmitted 35...44%		t  Voltage dips in vehicle electrical system to values below 9.5 V t  Open circuit or contact resistance in power supply to fresh air blower -V2-	–  Check alternator -C-, voltage regulator -C1-, battery -A- and corresponding wiring → Current flow diagrams, Electrical fault-finding and Fitting locations –  Use current flow diagram to check wiring to fresh air blower control unit -J126-
	t  Power supply too high / SP –  Duty cycle transmitted 25...34%		t  Voltage in vehicle electrical system has exceeded 15 V	–  Check alternator -C- and voltage regulator -C1- → Current flow diagrams, Electrical fault-finding and Fitting locations

Note t  The fresh air blower -V2- contains the fresh air blower control unit -J126- as an integral component which cannot be replaced separately. t  The status of the fresh air blower is displayed in the measured value block (display group “018”). By way of this status display, the operating and display unit, Climatronic control unit -J255- is informed by the fresh air blower control unit -J126- of any faults at the fresh air blower -V2- → Chapter. t  The fault “Power supply too high/SP” may also be displayed if an unsuitable charging unit is used for charging the battery -A-.

Indicated on vehicle diagnostic, testing and information system -VAS 5051A- and output on printer			Possible cause of trouble	Fault rectification
01274 Air flow flap control motor -V71-
	t  Blocked or deenergised / SP		t  Short circuit, open circuit in wiring or wiring fault between air flow flap control motor -V71- and operating and display unit, Climatronic control unit -J255- t  Fresh-air or air flow flap stiff (left-hand drive vehicles) t  Air flow flap control motor -V71- defective	–  Use current flow diagram to locate and eliminate short circuit, open circuit in wiring or wiring fault –  Check freedom of movement of fresh-air and air flow flap –  Check air flow flap control motor -V71- → Chapter
			t  Operating and display unit, Climatronic control unit -J255- incorrectly encoded. t  Convenience system central control unit -J393- incorrectly encoded.	–  Check encoding of operating and display unit, Climatronic control unit -J255- and code transmitted to operating and display unit, Climatronic control unit -J255- (Reading measured value block, display group “019”), → Chapter –  Check encoding of convenience system central control unit -J393- and encode control unit as specified if necessary → "Guided fault-finding" function of vehicle diagnostic, testing and information system VAS 5051 and → Electrical system; Rep. Gr.01

Note t  This control motor is only fitted on left-hand drive vehicles and is used to actuate the air flow/fresh-air flap. t  Right-hand drive vehicles are not fitted with this control motor. t  This fault is entered if the convenience system central control unit -J393- in a right-hand drive vehicle has been encoded for left-hand drive. The convenience system central control unit -J393- informs the operating and display unit, Climatronic control unit -J255- that the vehicle is of left-hand drive type. The operating and display unit, Climatronic control unit -J255- thus expects an air flow flap control motor -V71- with air flow flap control motor potentiometer -G113- to be connected. t  In the case of operating and display units, Climatronic control unit -J255- up to hardware/software version “0203”, the type of fault “Short to earth” or “Open circuit/short to positive” may also be displayed for this control motor. The cause of the trouble with these operating and display units, Climatronic control unit -J255- is the same as for the fault “Blocked or deenergised”.

Indicated on vehicle diagnostic, testing and information system -VAS 5051A- and output on printer			Possible cause of trouble	Fault rectification
01312 Drive train data bus
	Read out fault memory		t  The control unit in dash panel insert -J285- cannot output the required data on account of a fault and sets a fault message. t  The control unit in dash panel insert -J285- cannot output the required data on account of a fault in an upstream component and sets a fault message. t  A control unit linked to the drive data bus system is not supplying the required data or there is a fault in the drive data bus system.	–  Interrogate fault memory of control unit in dash panel insert -J285- → "Guided fault-finding" function of vehicle diagnostic, testing and information system VAS 5051 and → Electrical system; Rep. Gr.01 –  Determine and eliminate the causes of all faults stored in the fault memory of the control unit in dash panel insert -J285-. –  Interrogate fault memories of all control units connected to drive data bus system and locate and eliminate the drive data bus system faults displayed → "Guided fault-finding" function of vehicle diagnostic, testing and information system VAS 5051 and → Electrical system; Rep. Gr.01

Note If, for example, the engine control unit does not supply any information on the current engine speed (by way of the drive data bus system), the control unit in dash panel insert -J285- cannot incorporate this information into the data telegram for the convenience data bus system and this fault entry is made in the fault memory of the operating and display unit, Climatronic control unit -J255-.

Indicated on vehicle diagnostic, testing and information system -VAS 5051A- and output on printer			Possible cause of trouble	Fault rectification
01317 Control unit in dash panel insert -J285-
	t  Read out fault memory		t  The control unit in dash panel insert -J285- cannot output the required data on account of a fault and sets a fault message. t  The control unit in dash panel insert -J285- cannot output the required data on account of a fault in an upstream component and sets a fault message.	–  Interrogate fault memory of control unit in dash panel insert -J285- → "Guided fault-finding" function of vehicle diagnostic, testing and information system VAS 5051 and → Electrical system; Rep. Gr.01 –  Determine and eliminate the causes of all faults stored in the fault memory of the control unit in dash panel insert -J285-.
	t  No communication / SP		t  Open circuit in both signal wires (convenience data bus system) between control unit in dash panel insert -J285- and operating and display unit, Climatronic control unit -J255-	–  Use current flow diagram to locate and eliminate open circuit or loose contact at both signal wires (convenience data bus system) between control unit in dash panel insert -J285- and operating and display unit, Climatronic control unit -J255- –  Check convenience data bus system → Chapter.
Continued in next table

Indicated on vehicle diagnostic, testing and information system -VAS 5051A- and output on printer			Possible cause of trouble	Fault rectification
01317 (continued)
	t  No communication / SP		t  Fault affecting data output in control unit in dash panel insert -J285- or in a component connected to it	–  Interrogate fault memory of control unit in dash panel insert -J285- → "Guided fault-finding" function of vehicle diagnostic, testing and information system VAS 5051 and → Electrical system; Rep. Gr.01
			t  No data telegram transmitted by control unit in dash panel insert -J285-. t  The operating and display unit, Climatronic control unit -J255- cannot read the data telegram transmitted by the control unit in dash panel insert -J285-.	–  Check convenience data bus system → Chapter.
			t  Interruption of power supply to control unit in dash panel insert -J285- with ignition switched on	–  Interrogate and erase fault memories of all control units connected to the various data bus systems → "Guided fault-finding" function of vehicle diagnostic, testing and information system VAS 5051 and → Electrical system; Rep. Gr.01
Continued in next table

Indicated on vehicle diagnostic, testing and information system -VAS 5051A- and output on printer			Possible cause of trouble	Fault rectification
01317 (continued)
	t  No communication / SP		t  The control unit in dash panel insert -J285- transmits the information correctly, however this fault is entered in the operating and display unit, Climatronic control unit -J255- (up to software version “XX14”) on account of a specific optional extra.	–  Check display in measured value blocks “125” and “126” and heed the notes on display zone “1” in measured value block “125”.

Note Reception of the information is displayed in the measured value block (display group “125”) → Chapter.

Indicated on vehicle diagnostic, testing and information system -VAS 5051A- and output on printer			Possible cause of trouble	Fault rectification
01322 Multi-function unit control unit -J501-
	t  Read out fault memory t  No communication (time out) / SP		t  Refer to fault code “00457”On-board supply control unit -J519-	–  Interrogate fault memory of on-board supply control unit -J519- → "Guided fault-finding" function of vehicle diagnostic, testing and information system VAS 5051 and → Electrical system; Rep. Gr.01 –  Determine and eliminate the causes of all faults stored in the fault memory of the on-board supply control unit -J519-.

Note With certain operating and display units, Climatronic control unit -J255-, the multi-function unit control unit -J501- was stored as fault location in the software instead of the on-board supply control unit -J519-.

Indicated on vehicle diagnostic, testing and information system -VAS 5051A- and output on printer			Possible cause of trouble	Fault rectification
01326 Multi-function steering wheel control unit -J453-
	t  Read out fault memory t  No communication (time out) / SP		t  Refer to fault code “00466”Steering column electronics control unit -J527-	–  Interrogate fault memory of steering column electronics control unit -J527- → "Guided fault-finding" function of vehicle diagnostic, testing and information system VAS 5051 and → Electrical system; Rep. Gr.01 –  Determine and eliminate the causes of all faults stored in the fault memory of the steering column electronics control unit -J527-.

Note With certain operating and display units, Climatronic control unit -J255-, the multi-function steering wheel control unit -J453- was stored as fault location in the software instead of the steering column electronics control unit -J527-.

Indicated on vehicle diagnostic, testing and information system -VAS 5051A- and output on printer			Possible cause of trouble	Fault rectification
01330 Convenience system central control unit -J393-
	t  Read out fault memory		t  The convenience system central control unit -J393- cannot output the required data on account of a fault and sets a fault message. t  The convenience system central control unit -J393- cannot output the required data on account of a fault in an upstream component and sets a fault message.	–  Interrogate fault memory of convenience system central control unit -J393- → "Guided fault-finding" function of vehicle diagnostic, testing and information system VAS 5051 and → Electrical system; Rep. Gr.01 –  Determine and eliminate the causes of all faults stored in the fault memory of the convenience system central control unit -J393-.
	t  No communication (time out) / SP		t  Open circuit in both signal wires (convenience data bus system) between convenience system central control unit -J393- and operating and display unit, Climatronic control unit -J255-	–  Use current flow diagram to locate and eliminate open circuit or loose contact at both signal wires (convenience data bus system) between convenience system central control unit -J393- and operating and display unit, Climatronic control unit -J255- –  Check convenience data bus system → Chapter.
Continued in next table

Indicated on vehicle diagnostic, testing and information system -VAS 5051A- and output on printer			Possible cause of trouble	Fault rectification
01330 (continued)
	t  No communication (time out) / SP		t  Fault affecting data output in convenience system central control unit -J393- or in a component connected to it	–  Interrogate fault memory of convenience system central control unit -J393- → "Guided fault-finding" function of vehicle diagnostic, testing and information system VAS 5051 and → Electrical system; Rep. Gr.01
			t  No data telegram transmitted by convenience system central control unit -J393- t  The operating and display unit, Climatronic control unit -J255- cannot read the data telegram transmitted by the convenience system central control unit -J393-.	–  Check convenience data bus system → Chapter.
			t  Interruption of power supply to convenience system central control unit -J393- with ignition switched on	–  Interrogate and erase fault memories of all control units connected to convenience data bus system → "Guided fault-finding" function of vehicle diagnostic, testing and information system VAS 5051 and → Electrical system; Rep. Gr.01

Note Reception of the information is displayed in the measured value block (display group “125”) → Chapter.

Indicated on vehicle diagnostic, testing and information system -VAS 5051A- and output on printer			Possible cause of trouble	Fault rectification
01336 Group convenience data bus
	Fault (Bus Off)		t  Open circuit or short to earth/positive in convenience data bus system signal wire t  Short circuit between convenience data bus system signal wires	–  Use current flow diagram to locate and eliminate short circuit (to earth, positive or between signal wires) or open circuit in convenience data bus system wiring
			t  Convenience data bus system signal wires interchanged	–  Use current flow diagram to check signal wires of convenience data bus system.
			t  Destruction by one of the control units connected to the convenience data bus system of data telegram transmitted.	–  Check convenience data bus system → Chapter.
Continued in next table

Indicated on vehicle diagnostic, testing and information system -VAS 5051A- and output on printer			Possible cause of trouble	Fault rectification
01336 (continued)
	Fault (Bus Off)		t  Control unit not designed for data bus connected to convenience data bus system	–  Check part number of all control units connected to data bus system → "Guided fault-finding" function of vehicle diagnostic, testing and information system VAS 5051, → Electrical system; Rep. Gr.01 and → Parts List
	In one-wire operation		t  Open circuit or short to earth/positive in convenience data bus system signal wire	–  Use current flow diagram to locate and eliminate short circuit (to earth, positive or between signal wires) or open circuit in convenience data bus system wiring
			t  Destruction by one of the control units connected to the convenience data bus system of data telegram transmitted on one of the two signal wires.	–  Check convenience data bus system → Chapter.
Continued in next table

Indicated on vehicle diagnostic, testing and information system -VAS 5051A- and output on printer			Possible cause of trouble	Fault rectification
01336 (continued)
	t  No messages (time out for several control units)		t  Open circuit in wiring, e.g. at junction of convenience data bus system signal wires t  Open circuit in power supply to one or more control unit(s) connected to convenience data bus system	–  Use current flow diagram to locate and eliminate open circuit in wiring in convenience data bus system t  Use current flow diagram to locate and eliminate open circuit in power supply to one or more control unit(s) connected to convenience data bus system. → Current flow diagrams, Electrical fault-finding and Fitting locations, → "Guided fault-finding" function of vehicle diagnostic, testing and information system VAS 5051 and → Electrical system; Rep. Gr.01

Note Reception of the information is displayed in the measured value block (display group “125”) → Chapter.

Indicated on vehicle diagnostic, testing and information system -VAS 5051A- and output on printer			Possible cause of trouble	Fault rectification
01592 Air quality sensor -G238-
	t  Open circuit / short to positive / SP t  Short to earth / SP		t  Short circuit, open circuit in wiring or incorrectly assigned connectors between air quality sensor -G238- and operating and display unit, Climatronic control unit -J255- t  Incorrect version of operating and display unit, Climatronic control unit -J255-.	–  Use current flow diagram to locate and eliminate short (to earth or positive), open circuit in wiring or incorrectly assigned connectors between air quality sensor -G238- and operating and display unit, Climatronic control unit -J255- –  Check part number and index of operating and display unit, Climatronic control unit -J255- → Parts List
	t  Defective		t  Open circuit in power supply or earth connection to air quality sensor -G238- t  Air quality sensor -G238- defective	–  Locate and eliminate open circuit in power supply or earth connection to air quality sensor -G238- –  Replace air quality sensor -G238-
	t  Electr. fault in circuit / SP		t  Air quality sensor -G238- defective	–  Replace air quality sensor -G238-

Note Under certain circumstances, radio wave interference (e.g. amateur or police radio systems) may cause sporadic fault entries for the air quality sensor -G238-. This fault entry can be erased if applicable as the function of the operating and display unit, Climatronic control unit -J255- is not affected.

Indicated on vehicle diagnostic, testing and information system -VAS 5051A- and output on printer			Possible cause of trouble	Fault rectification
01593 Heated windscreen -Z2-
	t  Short to positive / SP		t  Operating and display unit, Climatronic control unit -J255- not encoded in specified manner.	–  Check encoding of operating and display unit, Climatronic control unit -J255- → Chapter (encoding for specific equipment).
			t  Short circuit or open circuit in wiring between heated windscreen control unit -J505- and operating and display unit, Climatronic control unit -J255- t  Open circuit in power supply or earth connection to heated windscreen control unit -J505-	–  Use current flow diagram to locate and eliminate short circuit or open circuit. –  Check actuation of heated windscreen -Z2- → Chapter
			t  Heated windscreen control unit -J505- defective	–  Replace heated windscreen control unit -J505-

Note t  If, on a vehicle with no heated windscreen -Z2-, the operating and display unit, Climatronic control unit -J255- is encoded for a vehicle with the heated windscreen -Z2- optional extra, the fault “Open circuit/short to earth” or “Short to positive” is entered (depending on software version in operating and display unit, Climatronic control unit -J255-). t  In the case of an operating and display unit, Climatronic control unit -J255- up to hardware/software version “0203”, the type of fault displayed for the heated windscreen -Z2- may also be “Open circuit/short to earth”. The cause of the trouble with these operating and display units, Climatronic control unit -J255- is the same as for the fault “Short to positive”.

Indicated on vehicle diagnostic, testing and information system -VAS 5051A- and output on printer			Possible cause of trouble	Fault rectification
01794 Control unit incorrect chassis number
			t  Chassis number stored in operating and display unit, Climatronic control unit -J255- different to that transmitted by convenience data bus system	–  Check transmitted and actual chassis number and compare to chassis number stored in operating and display unit, Climatronic control unit -J255- → Chapter (”Reading measured value block" function, display group “081”) and read out measured value block of control unit in dash panel insert -J285- → "Guided fault-finding" function of vehicle diagnostic, testing and information system VAS 5051 and → Electrical system; Rep. Gr. 01 –  Use the “Adaption” function to erase the chassis number stored in the operating and display unit, Climatronic control unit -J255- → Chapter.

Note t  New replacement operating and display units, Climatronic control unit -J255- are supplied without chassis number. The first time the ignition is switched on following installation, the chassis number transmitted via the convenience data bus system is read into the operating and display unit, Climatronic control unit -J255- (as of hardware/software version “0711”) and stored (anti-theft protection). t  The chassis number stored in the operating and display unit, Climatronic control unit -J255- is indicated in display group “081” → Chapter (Reading measured value block). t  If an operating and display unit, Climatronic control unit -J255- (as of hardware/software version “0711”) is fitted in a different vehicle (e.g. swapped over), the transmitted and stored chassis numbers no longer coincide and the fault “Control unit incorrect chassis number” is stored in the operating and display unit, Climatronic control unit -J255-. Entering the PIN in the “Adaption” function erases the chassis number stored in the operating and display unit, Climatronic control unit -J255- → Chapter.

Indicated on vehicle diagnostic, testing and information system -VAS 5051A- and output on printer			Possible cause of trouble	Fault rectification
01809 Left temperature flap control motor -V158-
	t  Blocked or deenergised / SP		t  Short circuit, open circuit in wiring or wiring fault between left temperature flap control motor -V158- and operating and display unit, Climatronic control unit -J255-	–  Use current flow diagram to locate and eliminate short circuit, open circuit in wiring or wiring fault
			t  Left temperature flap stiff t  Left temperature flap control motor -V158- defective	–  Check freedom of movement of left temperature flap –  Check left temperature flap control motor -V158- → Chapter

Note In the case of an operating and display unit, Climatronic control unit -J255- up to hardware/software version “0203”, the type of fault “Short to earth” or “Open circuit/short to positive” may also be displayed for this control motor. The cause of the trouble with these operating and display units, Climatronic control unit -J255- is the same as for the fault “Blocked or deenergised”.

Indicated on vehicle diagnostic, testing and information system -VAS 5051A- and output on printer			Possible cause of trouble	Fault rectification
01810 Right temperature flap control motor -V159-
	t  Blocked or deenergised / SP		t  Short circuit, open circuit in wiring or wiring fault between right temperature flap control motor -V159- and operating and display unit, Climatronic control unit -J255-	–  Use current flow diagram to locate and eliminate short circuit, open circuit in wiring or wiring fault
			t  Right temperature flap stiff t  Right temperature flap control motor -V159- defective	–  Check freedom of movement of right temperature flap –  Check right temperature flap control motor -V159- → Chapter

Note In the case of an operating and display unit, Climatronic control unit -J255- up to hardware/software version “0203”, the type of fault “Short to earth” or “Open circuit/short to positive” may also be displayed for this control motor. The cause of the trouble with these operating and display units, Climatronic control unit -J255- is the same as for the fault “Blocked or deenergised”.

Indicated on vehicle diagnostic, testing and information system -VAS 5051A- and output on printer			Possible cause of trouble	Fault rectification
01841 Left temperature flap control motor potentiometer -G220- in left temperature flap control motor -V158-
	t  Short to earth / SP t  Open circuit / short to positive / SP		t  Short circuit, open circuit in wiring or wiring fault between left temperature flap control motor potentiometer -G220- and operating and display unit, Climatronic control unit -J255- t  Left temperature flap control motor potentiometer -G220- in left temperature flap control motor -V158- defective	–  Use current flow diagram to locate and eliminate short circuit, open circuit in wiring or wiring fault –  Replace left temperature flap control motor -V158-
	t  Adaption limit exceeded		t  Temperature flap stiff t  Left temperature flap control motor potentiometer -G220- in left temperature flap control motor -V158- defective	–  Check freedom of movement of temperature flap –  Replace left temperature flap control motor -V158-

Note t  The fault “Adaption limit exceeded” is only detected during basic setting. If this fault occurs, a substitute value is stored as adaption value (adaption value for this potentiometer) and displayed in the corresponding measured value block. t  If the fault “Adaption limit exceeded” is displayed, check whether flap reaches both end stops and that there is no excessive play in the operating levers (wear).

Indicated on vehicle diagnostic, testing and information system -VAS 5051A- and output on printer			Possible cause of trouble	Fault rectification
01842 Right temperature flap control motor potentiometer -G221- in right temperature flap control motor -V159-
	t  Short to earth / SP t  Open circuit / short to positive / SP		t  Short circuit, open circuit in wiring or wiring fault between right temperature flap control motor potentiometer -G221- and operating and display unit, Climatronic control unit -J255- t  Right temperature flap control motor potentiometer -G221- in right temperature flap control motor -V159- defective	–  Use current flow diagram to locate and eliminate short circuit, open circuit in wiring or wiring fault –  Replace right temperature flap control motor -V159-
	Adaption limit exceeded		t  Temperature flap stiff t  Right temperature flap control motor potentiometer -G221- in right temperature flap control motor -V159- defective	–  Check freedom of movement of temperature flap –  Replace right temperature flap control motor -V159-

Note t  The fault “Adaption limit exceeded” is only detected during basic setting. If this fault occurs, a substitute value is stored as adaption value (adaption value for this potentiometer) and displayed in the corresponding measured value block. t  If the fault “Adaption limit exceeded” is displayed, check whether flap reaches both end stops and that there is no excessive play in the operating levers (wear).

Indicated on vehicle diagnostic, testing and information system -VAS 5051A- and output on printer			Possible cause of trouble	Fault rectification
65535 Control unit defective / SP
			t  Open circuit in wiring to operating and display unit, Climatronic control unit -J255- (terminal “30”, “75” or terminal “31”) t  Loose contact or contact resistance in wiring to operating and display unit, Climatronic control unit -J255-	–  Use current flow diagram to locate and eliminate fault in wiring –  Check buttons of operating and display unit, Climatronic control unit -J255- for dirt and clean if necessary.
			t  One or more buttons of operating and display unit, Climatronic control unit -J255- constantly pressed (button sticking)	–  Replace operating and display unit, Climatronic control unit -J255-
			t  Fault in program sequence of operating and display unit, Climatronic control unit -J255- t  Operating and display unit, Climatronic control unit -J255- defective	–  Replace operating and display unit, Climatronic control unit -J255-