Fuel Injectors, Checking

Fuel Injectors, Checking






Special Tools and Equipment
- VAG1526A
- VAG1527B
- VAG1594A
- VAG1598/31







Checking internal resistance
- Remove engine cover (arrows).
- Disconnect connector at the fuel injector to be tested.
- Connect multimeter at valve for resistance measurement.
- Specification: 12 to 13 Ohm (at room temperature)

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

If specified value is obtained:
- Check voltage supply

Checking voltage supply

Test requirements:
- Fuse for fuel injectors OK
- Fuel Pump (FP) relay OK;
- Disconnect harness connector at the fuel injector to be tested.







- Connect VAG1527B voltage tester as follows:

Harness connector Measure to
Terminal
1 Engine Ground (GND)

- Switch ignition on.
- LED must light up.

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

If LED lights up:
- Activation of fuel injectors, checking

Checking activation

Test requirement:
- Internal resistance of valve Ok
- Slide back rubber grommet 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 Engine Control Module (ECM), do not connect ECM. [1][2]Scan Tool Connecting and Initial Checks







- 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).