With Manufacturer's Scan Tool

Fuel Injectors, Checking

Special tools and equipment
- VAG1598/31 test box
- Multimeter (Fluke 83 or equivalent)
- VAG1527B voltage tester
- VW1594 adapter set
- Wiring diagram

Test requirements







- Fuses 28 and 32 OK
- Engine speed sensor OK (checking). Refer under "Powertrain Management/Computers and Control Systems/Engine Speed Sensor", Testing and Inspection
- Battery voltage at least 11.5 V
- Fuel pump relay OK

Test procedure


WARNING!
Fuel system is under pressure! Before opening the system place a cloth around the connection. Then release pressure by carefully loosening the connection.


- Remove intake manifold upper section.


NOTE: Seal the intake ports in the intake manifold lower section or in cylinder head with a clean cloth.


- Disconnect harness connectors from fuel injectors.

Checking resistance of fuel injectors







- Check resistance of fuel injectors between terminals.
Specified value: 13.0-19.0 ohms


NOTE: The resistance figures are valid for approx. 20 °C. At higher temperatures the resistance figures will increase.


If the specified value is not obtained:
- Replace faulty fuel injector, item 12. Refer to "Intake Manifold Lower Section, Disassembling and Assembling", Service and Repair

Pay attention to the following when installing the fuel injector:
- Replace O-rings on all fuel injectors and lightly moisten with clean engine oil.
- Insert fuel injectors vertically and in the correct position into the fuel rail and secure using retaining clips.
- Fit fuel rail with fuel injectors installed and secured on intake manifold lower section and press in evenly.

- Check DTC memory. If necessary, repair any malfunctions and erase DTC memory2.
- Display readiness code.

If DTC memory has been erased or the Engine Control Module (ECM) was disconnected from permanent battery (B+) voltage, the readiness code must be generated again.

Checking voltage supply







- Connect voltage tester to terminal -1- and Ground of relevant fuel injector harness connector.
- Operate starter and check voltage supply for fuel injector.
The LED must light up.

If the LED does not light up:
- Switch ignition off.
- Check wire between 2-pin harness connector terminal -1- and Fuel Pump (FP) relay -J17- for open circuit according to wiring diagram.
Wire resistance: max. 1.5 ohms

Checking activation and voltage supply







- Connect VAG1527B voltage tester to harness connector terminals of fuel injector to be tested using cables from VW1594.
- Operate starter and check activation of fuel injector.
The LED must flicker

If the LED does not flicker:
- Switch ignition off.
- Remove wiper arms and plenum chamber cover.







- Connect VAG1598/31 testbox to Engine Control Module (ECM) wiring harness. Engine Control Module (ECM) is not connected by this action.







- Check wiring between test box and fuel injector 2-pin harness connectors for open circuit according to wiring diagram.
- Injector 1: terminal -2- + socket 96
- Injector 2: terminal -2- + socket 112
- Injector 3: terminal -2- + socket 88
- Injector 4: terminal -2- + socket 113
- Injector 5: terminal -2- + socket 97
- Injector 6: terminal -2- + socket 89

- Wire resistance: max. 1.5 ohms

- Additionally, check wires for short to one another.
Specified value: infinity ohms

If there is no malfunction in the wiring, and the resistance measurement values are OK:
- Replace Engine Control Module (ECM).