Manufacturer's Scan Tool

Fuel Injectors, Checking

Special tools, testers and auxiliary items required

• Multimeter (V.A.G 1526 A)

• LED voltage tester (VAG1527B)

• Connector test kit (V.A.G 1594 A)

• Test box (VAG1598/31)

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. Refer to

• Fuel pump relay OK; checking. Refer to => [ Fuel Pump Relay and Relay Activation, Checking ] Fuel Pump Relay and Relay Activation, Checking.

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

- Remove connector on fuel injector to be checked.

- Connect LED voltage tester (VAG1527B) as follows:









- 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. Refer to

- 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 (VAG1527B) between terminals 2 (signal) and 1 (B+).





- Operate starter briefly.

• LED should flash.

• 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 (VAG1598/31) to wiring harness for Engine Control Module (ECM); do not connect ECM. Refer to => [ Electrical Testing, with Test Box VAG 1598/31 ] Electrical Testing, With Test Box VAG 1598/31.

- 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 ECM. Refer to => [ Engine Control Module without Metal Anti-Theft Housing, Replacing ] Engine Control Module Without Metal Anti-Theft Housing, Replacing.