Fuel Injectors, Checking

Fuel Injectors, Checking

Special tools and workshop equipment required
- V.A.G 1526 A Multimeter
- V.A.G 1527 B LED voltage tester
- V.A.G 1594 A Connector test kit
- V.A.G 1598/31 Test box

Work sequence

- Remove engine cover (arrows).

Checking internal resistance
- Remove connector on fuel injector to be checked.

- Connect multimeter to fuel injector to measure resistance.
- Specified value: 12 to 13 Ohms (at room temperature)

If specified value is not obtained:
- Replace fuel injector.

If specified value is obtained:

Checking power supply

Requirements
- Fuse for injectors OK
- Fuel pump relay OK; checking. Fuel Pump (FP) Relay -J17- and Activation, Checking

NOTE: The fuel injectors receive their power supply via the fuel pump relay.

- Remove connector on fuel injector to be checked.

- Connect LED voltage tester V.A.G 1527 B as follows:

Connector terminal Measure to
1 Engine ground (GND)

- Operate starter briefly.
- LED should light up.

If the LED does not light up:
- Check wiring connection between terminal 1 and fuse for fuel injector for open circuit:
- Repair any open circuit or wiring concerns.

If the LED lights up:

Checking activation

Requirements
- Internal resistance of the valve OK
- Push back rubber grommet of connector on fuel injector but leave connector attached.

- Connect LED voltage tester V.A.G 1527 B between terminals 2 (signal) and 1 (B+).
- Operate starter briefly.
- LED should flash.

NOTE: Voltage testers with a low current draw continue to glow faintly between activation from the engine control module (rather than extinguishing completely) and become slightly brighter when activated.

If LED does not flash:
- Connect test box V.A.G 1598/31 to wiring harness for Engine Control Module (ECM); do not connect Engine Control Module (ECM).

Check for open circuit, short to positive, or short to ground in following wiring connections:

- Repair any open/short circuit as necessary.

If the wiring is OK:
- Replace Engine Control Module (ECM).