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Home >> Audi >> 2007 >> Q7 4.2 >> Repair and Diagnosis >> Transmission >> Transmission Control Systems >> 4.2L - Generic Scan Tool - Engine Code: Bar (Engine DTC & Diagnostic Procedures) >> St Generic Scan Tool >> Diagnosis And Testing >> Diagnostic Procedures >> Engine Component Power Supply Relay -J757-, CHECKING
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Engine Component Power Supply Relay -J757-, CHECKING

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 

Test Requirements 

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
-- NO:
  • GATHER more information from customer about the complaint.
  • 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
-- 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
  • 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
-- 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
  • 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
-- 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
  • 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.