Audi Workshop Service and Repair Manuals

Fault table for faults with fault code as of “01406”

Indicated on vehicle diagnostic, testing and information system -VAS 5051A- and output on printer			Possible cause of trouble	Fault rectification
01406
No flame / SP
			t  Constriction of or leak in air intake area or exhaust system of auxiliary heater	–  Check air intake area and exhaust system of auxiliary heater. –  Perform final control diagnosis → Chapter.
			t  Fault in fuel supply to auxiliary heater –  Metering pump -V54- defective	–  Perform final control diagnosis → Chapter. –  Check fuel delivery of metering pump -V54- → Chapter.
			Fault in auxiliary heater electrical component t  Combustion air blower -V6- defective t  Glow plug for heater -Q9- defective t  Flame monitor -G64- contaminated or defective	–  Check auxiliary heater electrical components → Chapter.
			t  Leak in auxiliary heater	–  Dismantle and check auxiliary heater → Chapter.
			t  Residue in burner element (auxiliary heater operation with rape-oil or vegetable-oil methylester fuel only)	–  Dismantle auxiliary heater and remove residue from burner element → Chapter
			t  Atomiser unit has become detached from combustion air blower -V6-.	–  Dismantle auxiliary heater and check atomiser unit → Chapter.

WARNING As there may be unburnt fuel in the auxiliary heater, there is a possibility of fuel deflagration in the auxiliary heater when the auxiliary heater is first switched on after eliminating the fault. When this fault has been rectified, particular care should therefore be taken to ensure that the auxiliary heater exhaust gas is routed directly into a suitable exhaust gas extractor and drawn off.   Note t  If there is no proper flame formation in the auxiliary heater following several attempted starts or if the fault “Flame interruption” occurs several times in succession without intermediate trouble-free operation (more than approx. 70 ml (cm3) of fuel conveyed into the auxiliary heater), the auxiliary heater is interlocked (possibly too much fuel in the auxiliary heater). The auxiliary heater cannot be reactivated until the fault memory has been read out and erased. t  The auxiliary heater is interlocked for example after reaching the number of attempted starts without flame formation stored in the auxiliary heater control unit -J364-. This may be accompanied by switching to the fault “Flame interruption” or “Repeated flame interruption”. The auxiliary heater cannot be re-started until the fault memory has been erased. t  If the cause of the fault is not to be found in the “Fuel supply”, but rather in the exhaust system for example, fuel is conveyed into the auxiliary heater on each attempted start. t  If this fault is displayed, the problem may be incorrect routing of a fuel diversion pipe in the fuel tank. Should this fault occur, the fuel delivery is therefore to be checked with the fuel tank not more than 1/3 full. t  The atomiser unit is bolted to the shaft of the combustion air blower -V6-. If the bolt has not been properly fitted, it may work loose during heating operation → Chapter.

Indicated on vehicle diagnostic, testing and information system -VAS 5051A- and output on printer			Possible cause of trouble	Fault rectification
01407
Flame interruption / SP
			The causes of this fault entry are the same as for fault entry “01406”(No flame / SP)	→ Anchor (Fault entry “01406”(No flame / SP)

WARNING As there may be unburnt fuel in the auxiliary heater, there is a possibility of fuel deflagration in the auxiliary heater when the auxiliary heater is first switched on after eliminating the fault. When this fault has been rectified, particular care should therefore be taken to ensure that the auxiliary heater exhaust gas is routed directly into a suitable exhaust gas extractor and drawn off.   Note t  If there is no proper flame formation in the auxiliary heater following several attempted starts or if the fault “Flame interruption” occurs several times in succession without intermediate trouble-free operation (more than approx. 70 ml (cm3) of fuel conveyed into the auxiliary heater), the auxiliary heater is interlocked (possibly too much fuel in the auxiliary heater). The auxiliary heater cannot be reactivated until the fault memory has been read out and erased. t  The auxiliary heater is interlocked for example after reaching the number of attempted starts without flame formation stored in the auxiliary heater control unit -J364-. This may be accompanied by switching to the fault “Flame interruption” or “Repeated flame interruption”. The auxiliary heater cannot be re-started until the fault memory has been erased. t  If the cause of the fault is not to be found in the “Fuel supply”, but rather in the exhaust system for example, fuel is conveyed into the auxiliary heater on each attempted start. t  If this fault is displayed, the problem may be incorrect routing of a fuel diversion pipe in the fuel tank. Should this fault occur, the fuel delivery is therefore to be checked with the fuel tank not more than 1/3 full. t  To avoid critical fuel accumulation in the auxiliary heater, the auxiliary heater control unit -J364- switches off the auxiliary heater as soon as a calculated fuel quantity (max. 70 cm3) has been conveyed without a flame being detected by the flame monitor -G64- (e.g. after 3 attempted starts with start repetition).

Indicated on vehicle diagnostic, testing and information system -VAS 5051A- and output on printer			Possible cause of trouble	Fault rectification
01408
Undervoltage shutoff (fixed value) / SP
			t  Voltage dips during auxiliary heater operation to below the specified minimum voltage value	–  Check alternator -C- and voltage regulator. → Electrical system; Rep. Gr.01 and → "Guided fault-finding" function of vehicle diagnostic, testing and information system VAS 5051.
			t  Contact resistance in wiring between battery -A- and auxiliary heater control unit -J364-	–  Use current flow diagram to locate and eliminate contact resistance.
			t  Battery -A- insufficiently charged or defective	–  Check, re-charge or replace battery -A-.
			t  Fixed value entered for undervoltage shutoff too high	–  Use “Adaption” function to alter fixed value → Chapter

Note t  The undervoltage shutoff fixed value is active with code “00XX1”. It can be entered or altered by way of the “Adaption” function → Chapter. The current shutoff voltage value is displayed in the measured value block of the auxiliary heater control unit -J364- → Chapter. t  The fault “Undervoltage shutoff” results in deactivation of the auxiliary heater. The auxiliary heater cannot be re-started until the engine has been started at least once and the fault is no longer present (signal “Terminal 15 on” must be received at least once via convenience data bus system). t  The undervoltage shutoff fixed value is also active with code “00XX1” but is not displayed. If the voltage value has been altered for a control unit with code “00XX2” and the control unit was then re-encoded to “00XX1”, this fault may also be displayed for control units encoded for automatic undervoltage shutoff. Remedy: Set code of auxiliary heater control unit -J364- to “00XX2” → Chapter. Alter fixed value by way of “Adaption” function (specification less than 10.5 V) → Chapter and then set control unit code to “00XX1” again. t  In the event of frequent auxiliary heater operation, the battery -A- may no longer be sufficiently charged if the vehicle is only used for example for short journeys.

Indicated on vehicle diagnostic, testing and information system -VAS 5051A- and output on printer			Possible cause of trouble	Fault rectification
01409
Repeated flame interruption / SP
			The causes of this fault entry are the same as for fault entry “01406”(No flame / SP)	→ Anchor (Fault entry “01406”(No flame / SP)

WARNING As there may be unburnt fuel in the auxiliary heater, there is a possibility of fuel deflagration in the auxiliary heater when the auxiliary heater is first switched on after eliminating the fault. When this fault has been rectified, particular care should therefore be taken to ensure that the auxiliary heater exhaust gas is routed directly into a suitable exhaust gas extractor and drawn off.   Note t  If there is no proper flame formation in the auxiliary heater following several attempted starts or if the fault “Flame interruption” occurs several times in succession without intermediate trouble-free operation (more than approx. 70 ml (cm3) of fuel conveyed into the auxiliary heater), the auxiliary heater is interlocked (possibly too much fuel in the auxiliary heater). The auxiliary heater cannot be reactivated until the fault memory has been read out and erased. t  The auxiliary heater is interlocked for example after reaching the number of attempted starts without flame formation stored in the auxiliary heater control unit -J364-. This may be accompanied by switching to the fault “Flame interruption” or “Repeated flame interruption”. The auxiliary heater cannot be re-started until the fault memory has been erased. t  If the cause of the fault is not to be found in the “Fuel supply”, but rather in the exhaust system for example, fuel is conveyed into the auxiliary heater on each attempted start. t  If this fault is displayed, the problem may be incorrect routing of a fuel diversion pipe in the fuel tank. Should this fault occur, the fuel delivery is therefore to be checked with the fuel tank not more than 1/3 full.

Indicated on vehicle diagnostic, testing and information system -VAS 5051A- and output on printer			Possible cause of trouble	Fault rectification
01410
Heating unit overheating / SP –  Heater overheating fuse -S24- tripped
	t  Open circuit / short to positive / SP t  Short to earth / SP		t  Fault in wiring between auxiliary heater control unit -J364- and heater overheating fuse -S24- t  Heater overheating fuse -S24- defective	–  Use current flow diagram to locate and eliminate open circuit or short circuit in wiring. –  Check auxiliary heater electrical components → Chapter.
	t  No additional information on display		t  Air in coolant circuit t  Constriction in coolant circuit	–  Bleed coolant circuit in specified manner. –  Locate and eliminate constriction in coolant circuit.
			t  No circulation pump -V55- operation t  Temperature sensor -G18- not properly fitted (supplying incorrect temperature values) or defective t  Heater overheating fuse -S24- defective	–  Perform final control diagnosis → Chapter. –  Check auxiliary heater electrical components → Chapter.

Note t  The auxiliary heater does not start up in the event of the fault “Heating unit overheating”. The auxiliary heater cannot be re-started until the fault is no longer present. t  The heater overheating fuse -S24- opens at a coolant temperature in the auxiliary heater of greater than 110 °C and closes once the coolant temperature has dropped below 105 °C. t  The metering pump -V54- is actuated by the auxiliary heater control unit -J364- by way of the heater overheating fuse -S24-. t  The heater overheating fuse -S24- is only interrogated by the auxiliary heater control unit -J364- in auxiliary heating mode. However, in view of the fact that the auxiliary heater already switches to the control interval at a coolant temperature of 91 °C, this fault can only be entered if there is a fault in the coolant circuit even for vehicles with map-controlled cooling (higher coolant temperature) → Relevant engine, mechanics workshop manual.

Indicated on vehicle diagnostic, testing and information system -VAS 5051A- and output on printer			Possible cause of trouble	Fault rectification
01411
Temperature sensor -G18-
	t  Implausible signal / SP t  Open circuit / short to positive / SP t  Short to earth / SP		t  Fault in wiring between auxiliary heater control unit -J364- and temperature sensor -G18- t  Temperature sensor -G18- defective	–  Use current flow diagram to locate and eliminate open circuit or short circuit in wiring. –  Check auxiliary heater electrical components → Chapter.

Note The auxiliary heater does not start up in the event of the fault Temperature sensor -G18-. The auxiliary heater cannot be re-started until the fault is no longer present.

Indicated on vehicle diagnostic, testing and information system -VAS 5051A- and output on printer			Possible cause of trouble	Fault rectification
01413
Metering pump -V54-
	t  Open circuit / short to positive / SP t  Short to earth / SP		t  Fault in wiring between auxiliary heater control unit -J364- and metering pump -V54- t  Metering pump -V54- defective t  Fault in wiring between auxiliary heater control unit -J364- and heater overheating fuse -S24-	–  Use current flow diagram to locate and eliminate open circuit or short circuit in wiring. –  Check auxiliary heater electrical components → Chapter.

Note t  The auxiliary heater does not start up in the event of the fault Metering pump -V54-. The auxiliary heater cannot be re-started until the fault is no longer present. t  The metering pump -V54- is actuated by the auxiliary heater control unit -J364- by way of the heater overheating fuse -S24-.

Indicated on vehicle diagnostic, testing and information system -VAS 5051A- and output on printer			Possible cause of trouble	Fault rectification
01414
Combustion air blower -V6-
	t  Short to positive / SP t  Short to earth / SP t  Open circuit / SP t  Blocked or deenergised / SP t  Excessive speed deviation / SP		t  Fault in wiring between auxiliary heater control unit -J364- and combustion air blower -V6- t  Combustion air blower -V6- defective	–  Use current flow diagram to locate and eliminate open circuit or short circuit in wiring. –  Check auxiliary heater electrical components → Chapter.

Note The auxiliary heater does not start up in the event of the fault Combustion air blower -V6-. The auxiliary heater cannot be re-started until the fault is no longer present.

Indicated on vehicle diagnostic, testing and information system -VAS 5051A- and output on printer			Possible cause of trouble	Fault rectification
01415
Circulation pump -V55-
	t  Open circuit / short to positive / SP t  Short to earth / SP		t  Fault in wiring between auxiliary heater control unit -J364- and circulation pump -V55- t  Circulation pump -V55- defective	–  Use current flow diagram to locate and eliminate open circuit or short circuit in wiring. –  Check auxiliary heater electrical components → Chapter.
			t  Auxiliary heater control unit -J364- not encoded in specified manner	–  Auxiliary heater control unit -J364- not encoded in specified manner; check and if necessary correct encoding → Chapter.

Note t  With certain auxiliary heater control units -J364-, the “final control diagnosis” function results in storage of the fault circulation pump -V55- although there is no fault present and the circulation pump -V55- is functioning properly. In such cases, the fault memory is to be erased. t  The auxiliary heater does not start up in the event of the fault Circulation pump -V55-. The auxiliary heater cannot be re-started until the fault is no longer present. t  At present, the Audi A4 is always fitted with the circulation pump -V55-. For heaters to be introduced at a later date and only to be used as supplementary heaters, the option of operating the auxiliary heater as supplementary heater without a circulation pump is already available. t  At present, the circulation pump -V55- is not regulated by the auxiliary heater control unit -J364- but rather only switched on or off. At a later date, it is planned to install auxiliary heater control units -J364- which will regulate the delivery of the circulation pump -V55- as a function of the coolant temperature in the auxiliary heater (introduction not yet finalised). t  To assist the engine coolant pump, the circulation pump -V55- can also be activated with the auxiliary heater switched off → Chapter.

Indicated on vehicle diagnostic, testing and information system -VAS 5051A- and output on printer			Possible cause of trouble	Fault rectification
01416
Fresh air blower actuation signal
	t  Open circuit / short to positive / SP t  Short to earth / SP		t  Problem with actuation of fresh air blower -V2- by operating and display unit, Climatronic control unit -J255- (of air conditioner/heater)	–  Interrogate fault memory of operating and display unit, Climatronic control unit -J255- and eliminate cause of trouble. → Air conditioning; Rep. Gr.01 or → Heating; Rep. Gr.01
			t  Control unit in dash panel insert -J285- incorrectly encoded (incorrect adaption for auxiliary heater in channel “18” and / or “61”)	–  Check encoding and adaption of control unit in dash panel insert -J285- and correct if necessary. → Electrical system; Rep. Gr.01 and → "Guided fault-finding" function of vehicle diagnostic, testing and information system VAS 5051.

Note t  The fault “Fresh air blower actuation signal” does not result in deactivation of the auxiliary heater. t  The message indicating a fault at the fresh air blower -V2- is transmitted via the convenience data bus system by the operating and display unit, Climatronic control unit -J255-. t  Reception of the information is displayed in the measured value block of the auxiliary heater control unit -J364- (display group 125) → Chapter.

Indicated on vehicle diagnostic, testing and information system -VAS 5051A- and output on printer			Possible cause of trouble	Fault rectification
01443
Adaption to battery not performed / SP
			t  Adaption not performed after replacing auxiliary heater control unit -J364-	–  Check encoding of auxiliary heater control unit -J364- → Chapter and perform undervoltage shutoff adaption → Chapter.

Note t  The fault “Adaption to battery not performed” does not result in deactivation of the auxiliary heater. t  If adaption is not performed, auxiliary heater undervoltage shutoff takes place at 12.5 V.

Indicated on vehicle diagnostic, testing and information system -VAS 5051A- and output on printer			Possible cause of trouble	Fault rectification
01444
Undervoltage shutoff (automatic) / SP
			t  Voltage dips during auxiliary heater operation to below the specified minimum voltage value	–  Check alternator -C- and voltage regulator. → Electrical system; Rep. Gr.01 and → "Guided fault-finding" function of vehicle diagnostic, testing and information system VAS 5051. –  Check encoding of auxiliary heater control unit -J364- → Chapter and undervoltage shutoff adaption → Chapter.
			t  Contact resistance in wiring to auxiliary heater control unit -J364-	–  Use current flow diagram to locate and eliminate contact resistance.
			t  Battery -A- insufficiently charged or defective	–  Check, re-charge or replace battery -A-.

Note t  The fault “Undervoltage shutoff” results in deactivation of the auxiliary heater. The auxiliary heater cannot be re-started until the engine has been started at least once and the fault is no longer present (signal “Terminal 15 on” must be received at least once via the convenience data bus). t  The “Automatic” value for undervoltage shutoff is active with code “00XX1”. The current shutoff voltage value is displayed in the measured value block of the auxiliary heater control unit -J364- (display group “001”) → Chapter. t  In the event of frequent auxiliary heater operation, the battery -A- may no longer be sufficiently charged if the vehicle is only used for example for short journeys. t  If other faults are displayed together with the fault “Undervoltage shutoff (automatic)”, start by eliminating the cause of the fault “Undervoltage shutoff (automatic)”.

Indicated on vehicle diagnostic, testing and information system -VAS 5051A- and output on printer			Possible cause of trouble	Fault rectification
01490
Flame monitor -G64-
	t  Implausible signal / SP t  Open circuit / short to positive / SP t  Short to earth / SP		t  Fault in wiring between auxiliary heater control unit -J364- and flame monitor -G64-	–  Use current flow diagram to locate and eliminate open circuit or short circuit in wiring. –  Check auxiliary heater electrical components → Chapter.
			t  Flame monitor -G64- contaminated or defective	–  Remove flame monitor -G64-, check for contamination and replace if necessary → Chapter

Note t  The auxiliary heater does not start up in the event of the fault Flame monitor -G64-. The auxiliary heater cannot be re-started until the fault is no longer present. t  The flame monitor -G64- is a phototransistor. The flame monitor -G64- switches as soon as it is exposed to the brightness of a flame. The switching status of the flame monitor -G64- is displayed in the measured value block of the auxiliary heater control unit -J364- (display group “004”).

Indicated on vehicle diagnostic, testing and information system -VAS 5051A- and output on printer			Possible cause of trouble	Fault rectification
01491
Glow plug for heater -Q9-
	t  Open circuit / short to positive / SP t  Short to earth / SP		t  Fault in wiring between auxiliary heater control unit -J364- and glow plug for heater -Q9- t  Open circuit or contact resistance in earth connection of auxiliary heater control unit -J364- t  Glow plug for heater -Q9- defective	–  Use current flow diagram to locate and eliminate open circuit or short circuit in wiring. –  Check auxiliary heater electrical components → Chapter.

Note t  The auxiliary heater does not start up in the event of the fault Glow plug for heater -Q9-. The auxiliary heater cannot be re-started until the fault is no longer present. t  The earth connection between the glow plug for heater -Q9- and the auxiliary heater control unit -J364- is provided by way of a stud at the auxiliary heater housing. If applicable, check stud for firm attachment, contamination and corrosion.

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 auxiliary heater control unit -J364- different to that transmitted by convenience data bus system	–  Check transmitted and actual chassis numbers, compare to chassis number stored in auxiliary heater control unit -J364- → Chapter (”Reading measured value block" function, display group 081) and read out measured value block of control unit in dash panel insert -J285-. → Electrical system; Rep. Gr.01 and → "Guided fault-finding" function of vehicle diagnostic, testing and information system VAS 5051. –  Use “Adaption” function to erase chassis number stored in auxiliary heater control unit -J364- → Chapter.

Note t  New replacement auxiliary heater control units -J364- are supplied without chassis number. The first time the ignition is switched on following installation, the chassis number transmitted by way of the convenience data bus system is read into and stored in the auxiliary heater control unit -J364- (anti-theft protection). t  If the auxiliary heater control unit -J364- has been replaced and it is then not possible to switch on the auxiliary heater, heed the display in measured value block “090” of the auxiliary heater control unit -J364- → Chapter (“Reading measured value block” function). t  The chassis number stored in the auxiliary heater control unit -J364- is indicated in display group “081” → Chapter (”Reading measured value block" function). t  If an auxiliary heater control unit -J364- is installed 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 auxiliary heater control unit -J364-. The chassis number stored in the auxiliary heater control unit -J364- is erased by entering the PIN in the adaption function → Chapter. t  The fault “Control unit incorrect chassis number” does not result in deactivation of the auxiliary heater.

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 auxiliary heater control unit -J364- (terminal “30” or terminal “31”) t  Loose contact or contact resistance in wiring to auxiliary heater control unit -J364-	–  Use current flow diagram to locate and eliminate fault in wiring
			t  Fault in program sequence of auxiliary heater control unit -J364- t  Auxiliary heater control unit -J364- defective	–  Replace auxiliary heater control unit -J364-

Note The auxiliary heater does not start up in the event of the fault “Control unit defective”. The auxiliary heater cannot be re-started until the fault is no longer present.