With Generic Scan Tool

Fuel Injectors, Checking

Recommended special tools and equipment
- VAG1526 multimeter or VAG1715 multimeter
- VAG1527 voltage test lamp
- VAG1594 connector test kit
- Wiring diagram

Test requirements






- The respective fuses of fuel injectors (Cylinder 1 Fuel Injector -N30- to Cylinder 4 Fuel Injector -N33-) must be OK.
- Fuel Pump (FP) Relay -J17- must be OK, check:
- Battery voltage must be at least 11.5 volts.
- All electrical consumers such as, for example, lights and rear window defroster 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. Testing and Inspection
- Ignition switched off.

Test sequence
Resistance values of fuel injectors, checking






- Test resistance of fuel injectors between terminals.
Specified value: 12...17 ohms

NOTE: Resistance value is valid at approx. 20 degrees C. At higher temperatures, resistance value increases.

If specified value is not obtained:
- Replace malfunctioning fuel injector, item 10

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 distributor with secured fuel injectors on intake manifold and apply uniform pressure to press it in.

- Erase DTC memory of Engine Control Module (ECM), Diagnostic mode 4: Reset/erase diagnostic data. 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 fuel injector to be tested 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






- 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
- Also check wires for short circuit to B+ and Ground (GND).
Specified value: Infinite Ohms

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