With Generic Scan Tool

Fuel injectors, checking

Recommended special tools and equipment
- V.A.G 1526 multimeter or V.A.G 1715 multimeter
- V.A.G 1527 Voltage tester
- V.A.G 1594 Connector test set
- Wiring diagram

Test requirements





- The respective fuses of fuel injectors (-N30- to -N33-, -N83-, -N84-) must be OK:
- Fuel Pump (FP) Relay -J17- must be OK, check:
- Battery voltage must be at least 11.5 volts.
- All electrical consumers like, for example, lights and rear window heating must be switched off.
- Parking brake must be engaged or else daylight driving lights will be switched on.
- For vehicles with automatic transmission, selector lever must be in position -P- or -N-.
- If vehicle is equipped with an A/C system, it must be switched off.
- Ground (GND) connections between engine and chassis must be OK.
- Engine speed (RPM) sensor must be OK, checking
- Ignition switched off.

Test sequence





- Pull connectors -1- off connection -2- of all fuel injectors.

Resistance values of fuel injectors, checking





- Test resistance of fuel injectors between terminals.
Specified value: 13.5 to 15.5 Ohms

If specified value is not obtained:
- Replace malfunctioning fuel injector, item 7 .

Note the following when installing the fuel injectors:
- Replace O-rings on all fuel injectors and wet them slightly with clean motor oil.
- Insert fuel injectors into fuel rail perpendicular and in the right position, and secure them with retaining clips.
- Position fuel rail on intake manifold using secured fuel injectors and apply uniform pressure to press it in.

- Erase DTC memory of Engine Control Module (ECM), Diagnostic mode 4: Reset/erase diagnostic data.
- Generate readiness code. Monitors, Trips, Drive Cycles and Readiness Codes

Checking voltage supply





- 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.
- Switch ignition off.

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

Activation and voltage supply, checking





- Connect diode test lamp to the connector terminals of the fuel injector to be checked.
- Operate starter and test activation of fuel injector.
LED should flicker.
- Switch ignition off.

If LED does not flicker:
- Connect test box to control module wiring harness, connect test box for wiring test. Test Box, Connecting For Wiring Test






- Check wires between test box and 2-pin connector for open circuit according to wiring diagram.
Wire resistance: max: 1.5 Ohms

Vehicles with engine code AHA





Vehicles with engine code ATQ





Continuation for all vehicles
- Also check wires for short circuit to B+ or Ground (GND).
Specified value: Infinity Ohms

If there is no malfunction in wire connection:
- Replace Motronic Engine Control Module (ECM) -J220-.