A5 Quattro Coupe V6-3.2L (CALA) (2009)
If the specified value was not obtained:
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Using a multimeter, check the Motronic Engine Control Module (ECM) Power Supply Relay (J271) socket 8 to the Battery (A) (+) terminal for an
open circuit or short to Ground (GND).
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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:
Checking Ground (GND)
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Using a multimeter, check the Motronic Engine Control Module (ECM) Power Supply Relay (J271) socket 4/85 to the Engine Control Module
(ECM) (J623) electrical harness connector terminal T121/23 for resistance.
Ensure switch is off.
Specified value: 1.5 ohms.
If the specified value was not obtained:
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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 Motronic Engine Control Module (ECM) Power Supply Relay (J271). Refer to appropriate service information.
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Perform a road test to verify repair.
If the fault does not return:
Generate readiness code. Refer to => [ Readiness Code ] See: Powertrain Management/Computers and Control Systems/Testing and
Inspection/Monitors, Trips, Drive Cycles and Readiness Codes/Readiness Code.
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 appropriate service information.
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Assembly is performed in the reverse of the removal.
Final procedures
After the 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: Powertrain Management/Computers and Control
Systems/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: Powertrain Management/Computers and
Control Systems/Testing and Inspection/Scan Tool Testing and Procedures/Diagnostic Mode 01 - 09/Diagnostic Mode 04 - Erase DTC Memory.
3. If the DTC memory was erased, generate readiness code. Refer to => [ Readiness Code ] See: Powertrain Management/Computers and Control
Systems/Testing and Inspection/Monitors, Trips, Drive Cycles and Readiness Codes/Readiness Code.