Engine Component Power Supply Relay -J757-, Checking

WARNING: This page does not describe the selected car, but rather 12 other vehicles, including the 2017 Audi S5, 2016 Audi S5, 2016 Audi S4, 2015 Audi S5, and 2015 Audi S4. 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. CHECK: Engine Component Power Supply Relay -J757- socket terminals 1 and 3 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	CONNECT: Jumper wire, Engine Component Power Supply Relay -J757- socket terminals 3 and 5. 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 terminal 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	REMOVE: Jumper wire, Engine Component Power Supply Relay -J757- socket terminals 3 and 5. REMOVE: Engine Control Module -J623-. Refer to appropriate repair information. CHECK: Engine Component Power Supply Relay -J757- harness connector terminal 2 to the Engine Control Module -J623- harness connector T94 / 72 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. Clear the DTC's. Refer to DIAGNOSTIC MODE 04 - ERASE DTC MEMORY . Repair is complete. Generate Readiness Code. Refer to READINESS CODE . Return vehicle to Customer. If all electrical connections are OK: REPLACE: Engine Control Module -J623-. Refer to appropriate repair information. 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.