Fuel Injectors, Checking

Fuel injectors, checking

Electrical testing of fuel injectors
- Disconnect harness connector from injector to be tested.







- Connect multimeter to fuel injector (resistance measurement range).
Specification: 13 to 16 ohms


NOTE: When the engine is at operating temperature the electrical resistance of the injectors will be about 4 to 6 ohms higher.


If the specification is not obtained:
- Replace fuel injector.

If specification is met:
- Check voltage supply.

Checking voltage supply
- Disconnect harness connector from fuel injector to be tested.







- Connect diode test lamp (for measuring voltage) between Ground (GND) and socket 1 of connector.
- Operate starter for a few seconds (the engine can be allowed to start).
Specification: The diode test lamp should light up.

If the diode test lamp lights up:
- Check wiring connections.

If the diode test lamp does not light up:







- Test for continuity in the wiring from socket 1 to fuel pump relay via fuse for injectors. If necessary, correct open circuit.

Checking wiring connections
- Switch ignition off.
- Disconnect harness connector from injector to be tested.
- Connect VAG 1598/31 test box to wiring harness for engine control module. DO NOT connect to engine control module itself, Connecting VAG 1598/31 Test Box







- Test for open circuit and short to B+ or Ground (GND) in the following wiring connections:







- Correct any open/short circuit as necessary.
- If wiring is OK, replace engine control module.
- Generate readiness code, Readiness Code, Generating