Fuel Injectors, Checking

WARNING: This page is about a different car, the 2015 Audi A7 Quattro and 2014 Audi A7 Quattro. However, it is still accessible from the selected car via links, so may be relevant.

Function

The Cylinder 1, 2, 3, 4, 5, 6 Fuel Injectors -N30, N31, N32, N33, N83, N84- are controlled by the Engine Control Module -J623- and are mounted normally in the cylinder head. The fuel injectors spray high-pressure atomized fuel directly into the combustion chamber.

Special tools and workshop equipment required

Multimeter
Wiring Diagram
Scan Tool
LED Test Lamp

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 .

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 FUEL INJECTORS, CHECKING => 2 . -- NO: GATHER more information from customer about the complaint.
2	IGNITION: OFF. DISCONNECT: Faulty Fuel Injector -- from harness connector. CHECK: Faulty Fuel Injector -- component connector pins 1 and 2 for resistance. SPECIFIED VALUE: 0.5 - 35 Ω (@ approx. 20° C). -- Was Value obtained?	-- YES: GO TO Step 3 FUEL INJECTORS, CHECKING => 3 . -- NO: REPLACE: Faulty injector(s). Refer to appropriate repair information. GO TO: Step 4 FUEL INJECTORS, CHECKING => 4 .
3	REMOVE: Engine Control Module - J623-. Refer to appropriate service information. CHECK: Faulty Fuel Injector -- harness connector terminal 1 to the Engine Control Module - J623- harness connector terminal. (Refer to the wiring diagram for proper terminal locations). CHECK: Faulty Fuel Injector -- harness connector terminal 2 to the Engine Control Module - J623- harness connector terminal. (Refer to the wiring diagram for proper terminal locations). SPECIFIED VALUE: 0.5 Ω (± 0.3 Ω). -- Were Values obtained?	-- YES: REPLACE: Faulty Cylinder Fuel Injector -- for a mechanical condition. Refer to appropriate repair information. GO TO: Step 4 FUEL INJECTORS, CHECKING => 4 . -- NO: 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 4 FUEL INJECTORS, CHECKING => 4 .
4	Final Procedure Perform a road test to verify repair. Do any DTC's return:	-- YES: FAULT DOES RETURN: REPLACE: Engine Control Module - J623-. Refer to appropriate repair information. FAULT DOES NOT RETURN: Check the DTC memory. Refer to DIAGNOSTIC MODE 03 - READ DTC MEMORY . Perform the diagnostic procedure for that DTC. -- NO: Repair is complete. Generate readiness code. Refer to READINESS CODE . Return vehicle to Customer.