Fuel Injectors, Checking

Fuel Injectors, Checking

Special tools and equipment






- VAG1526A
- VAG1527B
- VAG1594A
- VAG1598/31

Checking internal resistance
- Disconnect harness connector at the fuel injector to be tested.

NOTE: In order to prevent a mix-up of the harness connectors at the fuel injectors, each group of two connectors are connected with a plastic track.






- Check resistance of individual fuel injectors.
Specification: 12 to 13 ohms (at room temperature)

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

If specified value is obtained:

Checking voltage supply

Test requirements
- Fuel Pump (FP) OK, checking. Fuel Pump (Fp) Relay -J17-, Testing and Activating
- Fuse for fuel injectors OK
- Disconnect harness connector at the fuel injector to be tested.

NOTE: In order to prevent a mix-up of the harness connectors at the fuel injectors, each group of two connectors are connected with a plastic track.






- Connect VAG1527B voltage tester as follows:

Harness connector Measure to
Terminal
1 Engine Ground (GND)

- Operate starter briefly (engine can also start).
- LED must light up.

If LED does not light up:
- Check wire connection between terminal 1 and fuse for fuel injector for open circuit.
- Repair open circuit if necessary.

If LED lights up:
- Check activation of fuel injectors.

Checking activation of fuel injectors

Test requirement:
- Internal resistance of valve OK
- Slide back rubber boot of fuel injector connector, but leave connector connected.






- Connect VAG1527B voltage tester between sockets 2 (signal) and 1 (B+).
- Operate starter briefly (engine can also start).
- LED must blink.

NOTE: Voltage testers do not go out completely during low current pick-up between activations by the ECM, but rather continue to glow a little and then get slightly brighter during activation.

If LED does not blink:
- Connect VAG1598/31 test box at wiring harness to ECM, do not connect ECM. Wiring and Component Testing Using VAG1598/31 Test Box






- Check the following wire connections for open circuit and short circuit to Ground (GND) and B+:






- Repair open circuit or short circuit if necessary.

If wire connection is OK:
- Replace Engine Control Module (ECM).