Low Fuel Pressure Sensor -G410-, 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 low-side fuel pressure is constantly monitored by the Low Fuel Pressure Sensor -G410- and sent to the Engine Control Module -J623-. If this pressure deviates from the desired pressure, the Engine Control Module -J623- sends a signal to the Fuel Pump Control Module -J538-. The Fuel Pump Control Module -J538- then sends a PWM signal to the Transfer Fuel Pump -G6- until the desired fuel pressure is achieved.

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: Low Fuel Pressure Sensor -G410- harness connector. IGNITION: ON. CHECK: Low Fuel Pressure Sensor -G410- harness connector terminals 1 to 3 for voltage. IGNITION: OFF. SPECIFIED VALUE: About 5.0 V. -- Was Value obtained?	-- YES: GO TO: Step 3 -- NO: GO TO: Step 4
3	REMOVE: Engine Control Module - J623-. Refer to appropriate repair information. CHECK: Low Fuel Pressure Sensor -G410- harness connector terminal 2 to the Engine Control Module - J623- harness connector T60 / 44 for resistance. SPECIFIED VALUE: 0.5 Ω (± 0.3 Ω). -- Was Value obtained?	-- YES: REPLACE: Low Fuel Pressure Sensor -G410-. 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
4	REMOVE: Engine Control Module - J623-. Refer to appropriate repair information. CHECK: Low Fuel Pressure Sensor -G410- harness connector terminal 1 to the Engine Control Module - J623- harness connector T60 / 50 for resistance. CHECK: Low Fuel Pressure Sensor -G410- harness connector terminal 3 to the Engine Control Module - J623- harness connector T60 / 35 for resistance. SPECIFIED VALUE: 0.5 Ω (± 0.3 Ω). -- Were Values obtained?	-- YES: 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.