S5 Quattro Coupe V8-4.2L (CAUA) (2009)
8 for an open circuit or short to Ground (GND).
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Check the electrical harness connectors for damage, corrosion, loose or broken terminals.
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If necessary, repair the wiring connection.
If no malfunctions are found in the wiring:
Checking Ground (GND)
If the manufacturers test box is being used, perform the following step.
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Install the test box.
If the manufacturers test box is not being used, perform the following step.
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Remove the Engine Control Module (ECM) (J623). Refer to => [ Engine Control Module, Replacing ] See: Service and Repair/Engine Control
Module, Replacing.
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Using a Multimeter, check the following wiring connection for resistance.
Specified value: 1.5 ohms.
If the specified value was not obtained:
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Check the Engine Component Power Supply Relay (J757) socket 4 to the Motronic Engine Control Module (ECM) (J623) electrical harness
connector T94 terminal 32 for an open circuit or a short to Battery (+).
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Check the electrical harness connector for damage, corrosion, loose or broken terminals.
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If necessary, repair the wiring connection.
If no malfunctions are found in the wiring and the voltage supply was OK:
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Replace the Engine Component Power Supply Relay (J757).
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Perform a road test to verify repair.
If the fault does not return:
Repair complete, Generate readiness code. Refer to => [ Readiness Code ] See: Testing and Inspection/Monitors, Trips, Drive Cycles and Readiness
Codes.
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End of diagnosis.
If the fault does return and no malfunction is detected in the wiring and the voltage supply was OK:
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Replace the Engine Control Module (ECM) (J623). Refer to => [ Engine Control Module, Replacing ] See: Service and Repair/Engine Control
Module, Replacing.
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Assembly is performed in the reverse of the removal.
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: Testing and Inspection/Scan Tool Testing and
Procedures/Diagnostic Mode 01 - 09/Diagnostic Mode 03 - Read DTC Memory.
2. If necessary, erase the DTC memory. Refer to => [ Diagnostic Mode 04 - Erase DTC Memory ] See: Testing and Inspection/Scan Tool Testing
and Procedures/Diagnostic Mode 01 - 09/Diagnostic Mode 04 - Erase DTC Memory.