Skoda Workshop Service and Repair Manuals > Octavia Mk1 > Drive unit | 2.0 ltr./85 kW Engine, Fuel Injection and Ignition System | Mixture preparation system, electronic inj.,Gas | Testing auxiliary signals | Testing databus (CAN bus)

Test sequence

–	Switch off ignition.

For engines with identification characters AEG, APK, AQY

–	Remove air filter.

–	Separate plug connections of control units with CAN databus → Current flow diagrams and Fitting locations.

–	Connect test box -V.A.G 1598/21- or -V.A.G 1598/33- to ABS wiring loom.

–	Test the central terminating resistor in the engine control unit:

–	Measure the resistance between sockets 10 + 11 (ABS) or 11 + 15 (ABS + ESP) at the test box:

Specified value: 60...72 Ω

If the resistance is not within the specified range:

–	Test wiring, rectify any faults in the CAN databus line → Electrical System → Rep. Gr.90.

If the resistance is not within the specified range and the CAN databus line is OK

–	Replace engine control unit → Chapter.

For engines with identification characters AZH, AZJ

–	Unlock connector at control unit and unplug.

–	Connect the -V.A.G 1598/31- to the engine control unit. The wiring loom of the control unit is not connected for this test.

–	Test the central terminating resistor in the engine control unit.

–	Carry out a resistance measurement for this purpose between sockets 58 and 60 of the test box.

Specified value: 60...72 Ω

If the resistance value is not within the nominal value range:

–	Replace engine control unit → Chapter.

If the resistance value is within the nominal value range:

–	Test CAN databus → Electrical System → Rep. Gr.90.

Skoda Workshop Service and Repair Manuals