Skoda Workshop Service and Repair Manuals

Fault table   Note t  As the control units are interlinked over a data BUS line, always start fault finding by activating the key function 00 „Automatic test sequence“ on all control units fitted to the vehicle. This allows to interrogate all the control units fitted in the vehicle in order to determine their possible faults. t  All the possible faults which can be detected by the ABS control unit -J104- and can be displayed by the -V.A.G 1552-, are listed according to their 5-digit fault code. t  The fault table may also display the fault type. t  The column „Fault elimination“ refers to certain test steps in the electrical test. t  Before replacing components found to be faulty, test all corresponding plug connections, lines and earth connections according to the current flow diagram → Current flow diagrams, Electrical fault finding and Fitting locations t  After carrying out the repair, always interrogate and erase the fault memory using the vehicle system tester -V.A.G 1552- and perform a test drive (at a speed above 20 km/h). t  After the test drive interrogate the fault memory again. Vehicles without CAN BUS

Readout on display -V.A.G 1552-	Possible cause of fault	Rectifying fault
No fault detected	If after repair „No fault detected“ is displayed, the self-diagnosis is completed. If the ABS does not operate without fault in spite of the display read-out „No fault detected“, proceed as follows: 1. Perform a test drive at a speed above 20 km/h, 2. Interrogate the fault memory again, if still no fault is stored, 3. continue fault finding without self-diagnosis and perform the electrical test completely → Chapter.
00283 Front left wheel speed sensor -G47-	t  Open circuit, short-circuit to positive or to earth or loose contact in the wiring between wheel speed sensor -G47- and ABS control unit -J104-	–  Check wiring and plug connections according to the current flow diagrams → Current flow diagrams, Electrical fault finding and Fitting locations –  Perform electrical Test → Chapter.
	t  Damage to the pulse rotor or to the wheel speed sensor -G47-	–  Check the wheel speed sensor -G47- and the pulse rotor for damage.
	t  Wheel speed sensor coil -G47- defective	–  Replace pulse rotor or wheel speed sensor -G47- → Chapter and → Chapter.
	t  ABS control unit -J104- defective	If the fault occurs again: –  Replace ABS control unit -J104- → Chapter.

Readout on display -V.A.G 1552-	Possible cause of fault	Rectifying fault
00283 Front left wheel speed sensor -G47- signal outside the tolerance 1)	t  Open circuit, short-circuit to positive or to earth or loose contact in the wiring between wheel speed sensor -G47- and ABS control unit -J104-	–  Check wiring and plug connections according to the current flow diagrams → Current flow diagrams, Electrical fault finding and Fitting locations –  Perform electrical Test → Chapter.
	t  Electrical malfunctions due to external interference (high-frequency irradiation, e.g. non-insulated ignition cable)	–  Reading measured value block → Chapter display group number 001.
	t  Damage to the pulse rotor or to the wheel speed sensor -G47-	–  Check the wheel speed sensor -G47- and the pulse rotor for damage.
	t  Air gap between wheel speed sensor -G47- and pulse rotor too great (signal N.O.K.)	–  Replace pulse rotor or wheel speed sensor -G47- → Chapter and → Chapter.
00283 Front left wheel speed sensor -G47- mechanical fault 1)	t  Air gap between wheel speed sensor -G47- and pulse rotor too great (signal N.O.K.)	–  Check the installation of the wheel speed sensor -G47- and the pulse rotor → Chapter and → Chapter. –  Reading measured value block → Chapter; display group number 002. –  Final control diagnosis performed → Chapter.
	t  Exhaust valves in the hydraulic unit -N55- defective	If the fault occurs again: –  Replace hydraulic unit -N55- → Chapter.

1) The type of fault can only be detected as of 20 km/h (perform test drive).

Readout on display -V.A.G 1552-	Possible cause of fault	Rectifying fault
00285 Front right wheel speed sensor -G45-	t  Open circuit, short-circuit to positive or to earth or loose contact in the wiring between wheel speed sensor -G45- and ABS control unit -J104-	–  Check wiring and plug connections according to the current flow diagrams → Current flow diagrams, Electrical fault finding and Fitting locations –  Perform electrical Test → Chapter.
	t  Damage to the pulse rotor or to the wheel speed sensor -G45-	–  Check the wheel speed sensor -G45- and the pulse rotor for damage.
	t  Wheel speed sensor coil -G45- defective	–  Replace pulse rotor or wheel speed sensor -G45- → Chapter and → Chapter.
	t  ABS control unit -J104- defective	If the fault occurs again: –  Replace ABS control unit -J104- → Chapter.
00285 Front right speed sensor -G45- signal outside the tolerance 1)	t  Open circuit, short-circuit to positive or to earth or loose contact in the wiring between wheel speed sensor -G45- and ABS control unit -J104-	–  Check wiring and plug connections according to the current flow diagrams → Current flow diagrams, Electrical fault finding and Fitting locations –  Perform electrical Test → Chapter.
	t  Electrical malfunctions due to external interference (high-frequency irradiation, e.g. non-insulated ignition cable)	–  Reading measured value block → Chapter; display group number 001.
	t  Damage to the pulse rotor or to the wheel speed sensor -G45-	–  Check the wheel speed sensor -G45- and the pulse rotor for damage.
	t  Air gap between wheel speed sensor -G45- and pulse rotor too great (signal N.O.K.)	–  Replace pulse rotor or wheel speed sensor -G45- → Chapter and → Chapter.
00285 Front right speed sensor -G45- mechanical fault 1)	t  Air gap between wheel speed sensor -G45- and pulse rotor too great (signal N.O.K.)	–  Check the installation of the wheel speed sensor -G45- and the pulse rotor → Chapter and → Chapter. –  Reading measured value block → Chapter; display group number 002. –  Final control diagnosis performed → Chapter.
	t  Exhaust valves in the hydraulic unit -N55- defective	If the fault occurs again: –  Replace hydraulic unit -N55- → Chapter.

1) The fault can only be detected as of 20 km/h (perform test drive).

Readout on display -V.A.G 1552-	Possible cause of fault	Rectifying fault
00287 Rear right wheel speed sensor -G44-	t  Open circuit, short-circuit to positive or to earth or loose contact in the wiring between wheel speed sensor -G44- and ABS control unit -J104-	–  Check wiring and plug connections according to the current flow diagrams → Current flow diagrams, Electrical fault finding and Fitting locations –  Perform electrical Test → Chapter.
	t  Damage to the pulse rotor or to the wheel speed sensor -G44-	–  Check the wheel speed sensor -G44- and the pulse rotor for damage.
	t  Wheel speed sensor coil -G44- defective	–  Replace pulse rotor or wheel speed sensor -G44- → Chapter and → Chapter.
	t  ABS control unit -J104- defective	If the fault occurs again: –  Replace ABS control unit -J104- → Chapter.
00287 Rear right speed sensor -G44- signal outside the tolerance 1)	t  Open circuit, short-circuit to positive or to earth or loose contact in the wiring between wheel speed sensor -G44- and ABS control unit -J104-	–  Check wiring and plug connections according to the current flow diagrams → Current flow diagrams, Electrical fault finding and Fitting locations –  Perform electrical Test → Chapter.
	t  Electrical malfunctions due to external interference (high-frequency irradiation, e.g. non-insulated ignition cable)	–  Reading measured value block → Chapter; display group number 001.
	t  Damage to the pulse rotor or to the wheel speed sensor -G44-	–  Check the wheel speed sensor -G44- and the pulse rotor for damage.
	t  Air gap between wheel speed sensor -G44- and pulse rotor too great (signal N.O.K.)	–  Replace pulse rotor or wheel speed sensor -G44- → Chapter and → Chapter.
00287 Rear right speed sensor -G44- mechanical fault 1)	t  Air gap between wheel speed sensor -G44- and pulse rotor too great (signal N.O.K.)	–  Check the installation of the wheel speed sensor -G44- and the pulse rotor → Chapter and → Chapter. –  Reading measured value block → Chapter; display group number 002. –  Final control diagnosis performed → Chapter.
	t  Exhaust valves in the hydraulic unit -N55- defective	If the fault occurs again: –  Replace hydraulic unit -N55- → Chapter.

1) The fault can only be detected as of 20 km/h (perform test drive).

Readout on display -V.A.G 1552-	Possible cause of fault	Rectifying fault
00290 Speed sensor rear left -G46-	t  Open circuit, short-circuit to positive or to earth or loose contact in the wiring between wheel speed sensor -G46- and ABS control unit -J104-	–  Check wiring and plug connections according to the current flow diagrams → Current flow diagrams, Electrical fault finding and Fitting locations –  Perform electrical Test → Chapter.
	t  Damage to the pulse rotor or to the wheel speed sensor -G46-	–  Check the wheel speed sensor -G46- and the pulse rotor for damage.
	t  Wheel speed sensor coil -G46- defective	–  Replace pulse rotor or wheel speed sensor -G46- → Chapter and → Chapter.
	t  ABS control unit -J104- defective	If the fault occurs again: –  Replace ABS control unit -J104- → Chapter.
00290 Rear left wheel speed sensor -G46- signal outside the tolerance 1)	t  Open circuit, short-circuit to positive or to earth or loose contact in the wiring between wheel speed sensor -G46- and ABS control unit -J104-	–  Check wiring and plug connections according to the current flow diagrams → Current flow diagrams, Electrical fault finding and Fitting locations –  Perform electrical Test → Chapter.
	t  Electrical malfunctions due to external interference (high-frequency irradiation, e.g. non-insulated ignition cable)	–  Reading measured value block → Chapter; display group number 001.
	t  Damage to the pulse rotor or to the wheel speed sensor -G46-	–  Check the wheel speed sensor -G46- and the pulse rotor for damage.
	t  Air gap between wheel speed sensor -G46- and pulse rotor too great (signal N.O.K.)	–  Replace pulse rotor or wheel speed sensor -G46- → Chapter and → Chapter.
00290 Rear left speed sensor -G46- mechanical fault 1)	t  Air gap between wheel speed sensor -G46- and pulse rotor too great (signal N.O.K.)	–  Check the installation of the wheel speed sensor -G46- and the pulse rotor → Chapter and → Chapter. –  Reading measured value block → Chapter; display group number 002. –  Performing actuator diagnosis → Chapter.
	t  Exhaust valves in the hydraulic unit -N55- defective	If the fault occurs again: –  Replace hydraulic unit -N55- → Chapter.

1) The fault can only be detected as of 20 km/h (perform test drive).

Readout on display -V.A.G 1552-	Possible cause of fault	Rectifying fault
00668 Onboard voltage tml. 30 signal outside the tolerance	t  Open circuit, short-circuit to positive or earth	–  Check wiring and plug connections according to the current flow diagrams → Current flow diagrams, Electrical fault finding and Fitting locations –  Perform electrical test → Chapter and continue.
01044 Control unit wrongly coded	t  ABS control unit -J104- incorrectly coded	–  Check coding of the ABS control unit -J104- → Chapter
	t  Bridge in the multi-pin connector to the ABS control unit -J104- from contact 3 to contact 14 interrupted or short-circuited	–  Check wiring and plug connections according to the current flow diagrams → Current flow diagrams, Electrical fault finding and Fitting locations –  Perform electrical test → Chapter and continue.
01130 ABS operation Implausible signal1)	t  Electrical malfunctions due to external interference (high-frequency irradiation, e.g. non-insulated ignition cable)	–  Erase fault memory. –  Perform a test drive at a speed above 20 km/h. –  Interrogate the fault memory again.
	t  Open circuit, short-circuit to positive or earth	–  Check wiring and plug connections according to the current flow diagrams → Current flow diagrams, Electrical fault finding and Fitting locations –  Perform electrical test → Chapter and continue.
	t  ABS control unit -J104- defective	If the fault occurs again: –  Replace ABS control unit -J104- → Chapter.
01276 ABS hydraulic pump -V64- signal outside the tolerance 1)	t  Plug connection E-engine to control unit	–  Performing actuator diagnosis → Chapter.
	t  Open circuit, short-circuit to positive or earth	–  Check wiring and plug connections according to the current flow diagrams → Current flow diagrams, Electrical fault finding and Fitting locations –  Perform electrical Test → Chapter.
	t  ABS hydraulic pump -V64- defective	–  If the hydraulic pump -V64- starts without fault when carrying out the test step no. 18 in the electrical test → Chapter, then the ABS control unit must be replaced -J104-.
	t  ABS control unit -J104- defective	–  Replace ABS control unit -J104- → Chapter.

1) The fault can only be detected as of 20 km/h (perform test drive).

Readout on display -V.A.G 1552-	Possible cause of fault	Rectifying fault
01312 Databus drive defective 1) or	t  ABS control unit -J104- incorrectly coded	–  Check coding of the ABS control unit -J104- → Chapter
	t  Engine control unit incorrectly coded	–  Test engine control unit → Relevant Engine; Rep. gr.01
	t  Open circuit, short-circuit to positive or earth	–  Check wiring and plug connections according to the current flow diagrams → Current flow diagrams, Electrical fault finding and Fitting locations –  Perform electrical test → Chapter and continue.
Databus drive defective 1) sporadic	t  Ignition key turns too slowly in the ignition lock	–  Erasing fault memory → Chapter –  No further measures required. –  Inform customer (inform).
01314 Engine control unit no communication	t  Open circuit in the data BUS lines, short-circuit to positive or to earth	–  Check data BUS wiring and plug connections according to the current flow diagrams → Current flow diagrams, Electrical fault finding and Fitting locations –  Perform electrical test → Chapter and continue.
01315 Gearbox control unit 2) no communication	t  Open circuit in the data BUS lines, short-circuit to positive or to earth	–  Check data BUS wiring and plug connections according to the current flow diagrams → Current flow diagrams, Electrical fault finding and Fitting locations –  Perform electrical test → Chapter and continue.
01316 Brake control unit no communication	t  Open circuit in the data BUS lines, short-circuit to positive or to earth	–  Check data BUS wiring and plug connections according to the current flow diagrams → Current flow diagrams, Electrical fault finding and Fitting locations –  Perform electrical test → Chapter and continue.

1) The fault „data BUS drive defective“ does not result in the ABS warning light -K47- or the hand brake/brake fluid level warning light -K14/33- lighting up. The ABS function is fully maintained.

2) Only on vehicles with automatic gearbox.

Readout on display -V.A.G 1552-	Possible cause of fault	Rectifying fault
18256 Please read out fault memory of the engine CU	t  Fault entry in 4AV control unit	–  Interrogate the fault memory of the engine control unit → Relevant engine identification characters; Rep. gr.01
65535 Control unit defective	t  ABS control unit -J104- defective	–  Replace control unit -J104- → Chapter.