Test Procedure

WARNING: This page is about a different car, the 2018 Audi A3 Quattro, 2017 Audi A3 Quattro, 2016 Audi A3 Quattro, 2016 Audi A3, and 2015 Audi A3 Quattro. However, it is still accessible from the selected car via links, so may be relevant.

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. REMOVE: Evaporative Canister. Refer to appropriate Service Information. Plug or Cap off the Fuel Tank Pressure Sensor -G400- hose going to the vent filter. CONNECT: Hand vacuum pump to the Fuel Tank Pressure Sensor -G400- and apply 0.700 bar and see if the vacuum holds. -- Did the vacuum hold?	-- YES: GO TO: Step 3. -- NO: REPLACE: Fuel Tank Pressure Sensor -G400-. Refer to appropriate Service Information. GO TO: Step 7.
3	DISCONNECT: Fuel Tank Pressure Sensor -G400- harness connector CHECK: Fuel Tank Pressure Sensor -G400- component connector terminals 1 to 3 for resistance. SPECIFIED VALUE: 20 - 40 Ω (± 5.0 Ω @ approx. 20° C). -- Was Value 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 7.
4	REMOVE: Engine Control Module - J623-. Refer to appropriate Service Information. CHECK: Fuel Tank Leak Detection Control Module -J909 - harness connector terminal 1 to the Fuel Tank Pressure Sensor -G400- harness connector terminal 1 for resistance. CHECK: Fuel Tank Leak Detection Control Module -J909 - harness connector terminal 5 to the Fuel Tank Pressure Sensor -G400- harness connector terminal 3 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 7.
5	IGNITION: ON. CHECK: Fuel Tank Leak Detection Control Module -J909 - harness connector terminal 4 to ground for voltage. IGNITION: OFF. SPECIFIED VALUE: Battery Voltage. -- Was Value obtained?	-- YES: GO TO: Step 6. -- 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 7.
6	REMOVE: Engine Control Module - J623-. Refer to appropriate Service Information. CHECK: Fuel Tank Leak Detection Control Module -J909 - harness connector terminal 2 to the Engine Control Module - J623- harness connector T91 / 38 for resistance. CHECK: Fuel Tank Leak Detection Control Module -J909 - harness connector terminal 3 to the Engine Control Module - J623- harness connector T91 / 78 for resistance. SPECIFIED VALUE: 0.5 Ω (± 0.3 Ω). -- Were Values obtained?	-- YES: REPLACE: Fuel Tank Leak Detection Control Module -J909 -. Refer to appropriate Service Information. GO TO: Step 7. -- 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 7.
7	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 Service Information. 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. -- NO: Perform the diagnostic procedure for any DTC's. If no DTC's return, the repair is complete. Return vehicle to customer.