Q7 Quattro V8-4.2L (BAR) (2008)
If the specified value was obtained:
Checking wiring
If the manufacturers test box is being used. Perform the following step.
-
Install the test box.
If the manufacturers test box is not being used. Perform the following step.
-
Remove the Engine Control Module (ECM) (J623). Refer to => [ Engine Control Module, Replacing ] See: Service and Repair/Engine Control
Module, Replacing.
-
Using a Multimeter, check the Can-Bus Disconnection plug electrical harness connector terminals to the Engine Control Module (ECM) (J623)
electrical harness connector T94 for resistance.
Specified value: 1.5 ohms Max.
If the specified value was not obtained:
-
Check the wiring for a open circuit, short circuit to each other, Battery (+), or Ground (GND).
-
Check the electrical harness connector for damage, corrosion, loose or broken terminals.
-
If necessary, repair the faulty wiring connection.
If no malfunction is detected in the wiring and if the voltage supply was OK:
-
Erase the DTC memory. Refer to => [ Diagnostic Mode 04 - Erase DTC Memory ] See: Computers and Control Systems/Testing and
Inspection/Scan Tool Testing and Procedures/Diagnostic Modes 01 - 09/Diagnostic Mode 04 - Erase DTC Memory
-
Perform a road test to verify repair.
If the DTC does not return:
Repair complete, Generate readiness code. Refer to => [ Readiness Code ] See: Computers and Control Systems/Testing and Inspection/Monitors,
Trips, Drive Cycles and Readiness Codes.
-
End diagnosis.
If the DTC does return and no malfunction is detected in the wiring and the resistance was not OK:
-
Replace the Engine Control Module (ECM) (J623). Refer to => [ Engine Control Module, Replacing ] See: Service and Repair/Engine Control
Module, Replacing.
Final procedures
After repair work, the following work steps must be performed in the following sequence:
1. Check the DTC memory. Refer to => [ Diagnostic Mode 03 - Read DTC Memory ] See: Computers and Control Systems/Testing and
Inspection/Scan Tool Testing and Procedures/Diagnostic Modes 01 - 09/Diagnostic Mode 03 - Read DTC Memory
2. If necessary, erase the DTC memory. Refer to => [ Diagnostic Mode 04 - Erase DTC Memory ] See: Computers and Control Systems/Testing and
Inspection/Scan Tool Testing and Procedures/Diagnostic Modes 01 - 09/Diagnostic Mode 04 - Erase DTC Memory
3. If the DTC memory was erased, generate readiness code. Refer to => [ Readiness Code ] See: Computers and Control Systems/Testing and
Inspection/Monitors, Trips, Drive Cycles and Readiness Codes.
End diagnosis