Engine Component Power Supply Relay -J757-, CHECKING

WARNING: This page is about a different car, the 2010 Audi Q7, 2009 Audi Q7, 2008 Audi Q7, and 2007 Audi Q7. However, it is still accessible from the selected car via links, so may be relevant.

General Description

The following procedure is used to diagnose the Engine Component Power Supply Relay -J757- and the power supply voltage that is provided to the engine components.

Special tools and workshop equipment required

Multimeter.
Wiring Diagram.
Scan Tool.

Test Requirements

Fuses OK.
Battery voltage OK.
Switch OFF all electrical and electronic accessories.
Vehicles with Auto. Transmission, ensure Selector Lever position is in "P".
Vehicles with Man. Transmission, ensure Shifter Lever position is in "N" with Parking Brake applied.
Coolant Temperature: ≥ 80° C.
Observe all safety precautions: SAFETY PRECAUTIONS .
View clean working conditions: CLEAN WORKING CONDITIONS .
For Hybrid vehicles refer to: HIGH VOLTAGE SYSTEM GENERAL WARNINGS .

Test Procedure

Step	Procedure	Result / Action to Take
1	PERFORM: Preliminary Check to verify the customers complaint. Refer to PRELIMINARY CHECK . -- Was Complaint verified?	-- YES: GO TO: Step 2 -- NO: GATHER more information from customer about the complaint.
2	IGNITION: OFF. DISCONNECT: Engine Component Power Supply Relay -J757- from the Fuse box in the engine compartment. IGNITION: ON. For 2007 - 2009 MY: CHECK: Engine Component Power Supply Relay -J757- socket terminals A3d and A3b to ground for voltage. For 2010 MY: CHECK: Engine Component Power Supply Relay -J757- socket terminals A1f and A1h to ground for voltage. IGNITION: OFF. SPECIFIED VALUE: Battery voltage. -- Were Values obtained?	-- YES: GO TO: Step 3 -- NO: PERFORM: Visual Inspection of wiring and component. CHECK: Wiring for open, high resistance, short or harness connector for damage, corrosion, loose or broken terminals. REPAIR: Faulty wiring or connector. GO TO: Step 5
3	For 2007 - 2009 MY: CONNECT: Jumper wire, between the Engine Component Power Supply Relay -J757- socket terminals A3b and A3a. For 2010 MY: CONNECT: Jumper wire, between the Engine Component Power Supply Relay -J757- socket terminals A1h and A1b. DISCONNECT: Ignition Coil 1, 2, 3, 4 With Power Output Stage -N70, N127, N291, N292- harness connectors. IGNITION: ON. CHECK: Ignition Coil 1, 2, 3, 4 With Power Output Stage -N70, N127, N291, N292- harness connector terminals 1 to ground for voltage. IGNITION: OFF. SPECIFIED VALUE: Battery voltage. -- Were Values obtained?	-- YES: GO TO: Step 4 -- NO: PERFORM: Visual Inspection of wiring and component. CHECK: Wiring for open, high resistance, short or harness connector for damage, corrosion, loose or broken terminals. REPAIR: Faulty wiring or connector. GO TO: Step 5
4	For 2007 - 2009 MY: REMOVE: Jumper wire, between the Engine Component Power Supply Relay -J757- socket terminals A3b and A3a. For 2010 MY: REMOVE: Jumper wire, between the Engine Component Power Supply Relay -J757- socket terminals A1h and A1b. REMOVE: Engine Control Module -J623-. Refer to appropriate repair information. For 2007 - 2009 MY: CHECK: Engine Component Power Supply Relay -J757- socket terminal A3c to the Engine Control Module -J623- harness connector T94 / 32 for resistance. For 2010 MY: CHECK: Engine Component Power Supply Relay -J757- socket terminal A1d to the Engine Control Module -J623- harness connector T94 / 32 for resistance. SPECIFIED VALUE: 0.5 Ω (± 0.3 Ω). -- Was Value obtained?	-- YES: REPLACE: Engine Component Power Supply Relay -J757-. Refer to appropriate repair information. GO TO: Step 5 -- NO: PERFORM: Visual Inspection of wiring and component. CHECK: Wiring for open, high resistance, short or harness connector for damage, corrosion, loose or broken terminals. REPAIR: Faulty wiring or connector. GO TO: Step 5
5	Final Procedure Perform a road test to verify repair. -- Does the original DTC return?	-- YES: CHECK: Engine Control Module -J623- harness connector for any damaged, pushed-out pins. REPAIR: As necessary. If all electrical connections are OK: REPLACE: Engine Control Module -J623-. Refer to appropriate repair information. Clear the DTCs. Refer to DIAGNOSTIC MODE 04 - ERASE DTC MEMORY . Repair is complete. Generate Readiness Code. Refer to READINESS CODE . Return vehicle to Customer. -- NO: Perform the diagnostic procedure for any DTC's. If no DTC's return, the repair is complete. Return vehicle to customer.