Fuel Injectors, Checking
Special tools and equipment
- VAG 1598/31 adapter cable
- VAG 1526 multimeter or VAG 1715 multimeter
- VAG 1527A voltage tester
- VAG 1594 connector test kit
- Wiring diagram
Test requirements
- Engine speed (RPM) sensor must be OK. Engine Speed (RPM) Sensor -G28- Checking
- Fuel Pump (FP) relay must be OK.
- Fuses no. 28 and 32 must be OK.
Resistance values of fuel injectors, checking
- Test resistance of fuel injectors between terminals. Specification: 12 to 17 Ohms
NOTE: Resistance value is valid at approx. 20 °C. At higher temperatures, resistance value increases.
If specified value is not obtained:
- Replace faulty fuel injector
Checking voltage Supply
I - Engine code ATW
II - Engine codes AUG, AWM
- Disconnect fuel injector connectors.
- Connect diode test lamp to connector of tested fuel injector terminal 1 and Ground (GND).
- Operate starter and test voltage supply for fuel injector. LED must light up.
If LED does not light up:
- Switch ignition off.
- Check wire between 2-pin connector terminal 1 and Fuel Pump (FP) relay -J17- for open circuit according to wiring diagram. Wire resistance: max: 1.5 Ohms
Activation and voltage supply, checking
I - Engine code ATW
II - Engine codes AUG, AWM
- Disconnect fuel injector connectors.
- Use adapter cables from the VAG 1594 connector test kit to connect VAG 1527 diode test lamp to the connector terminals of the fuel injector to be tested.
- Operate starter and test activation of fuel injector. LED should flicker.
If LED does not flicker:
- Switch ignition off.
- Connect VAG 1598/31 adapter cable to control module wiring harness. Engine Control Module (ECM) is not connected.
- Use wiring diagram to check wires between test box and harness connector for open circuits or short circuits to Ground (GND) or B+.
Fuel injector 1: Terminal 2 + socket 96
Fuel injector 2: Terminal 2 + socket 89
Fuel injector 3: Terminal 2 + socket 97
Fuel injector 4: Terminal 2 + socket 88
Wire resistance: max: 1.5 Ohms
If there is no malfunction in wire connection:
- Replace Engine Control Module (ECM).