Fuel Injectors, Checking
The following test procedure is used to diagnose all fuel injectors.
Special tools and workshop equipment required
- Multimeter.
- Diode test lamp 12V.
- Wiring diagram.
Test requirements
- The Fuel Injectors -N30, N31, N32, N33- fuses OK.
- The Engine Speed (RPM) Sensor -G28- is OK.
- Battery voltage at least 12.5 volts.
- All electrical consumers such as, lights and rear window defroster, switched off.
- Vehicles with automatic transmission, shift selector lever into position "P" or "N".
- A/C switched off.
- Ground connections between engine/transmission/chassis OK.
- Ignition switched off.
-- Observe safety precautions.
-- Observe rules for cleanliness.
Test procedure
-- Perform a preliminary check to verify the customers complaint. Refer to PRELIMINARY CHECK
Start diagnosis
-- Remove the engine cover.
-- Disconnect the Fuel Injector -- electrical harness connectors from Fuel Injectors -N30, N31, N32, N33-.
Checking internal resistance
-- Using a multimeter, check the Fuel Injector -- electrical terminals 1 to 2 for resistance.
Specified value: 12.0 to 20.0 Ω (at approx. 20° C)
If the specified value was Not obtained:
-- Replace the malfunctioning Fuel Injector.
If the specified value was obtained:
Checking activation and wiring
-- Connect a diode test lamp to the electrical harness connector terminals 1 and 2 of the Fuel Injector -- to be tested.
-- Operate the starter and test the activation of the Fuel Injector --.
LED should flicker.
-- Switch the ignition off.
If LED does not flicker:
-- Remove the Engine Control Module (ECM) -J623-.
-- Using a multimeter, check the Fuel Injector -- electrical harness connector terminals to the Engine Control Module (ECM) -J623- electrical harness connector T60 terminals for an open circuit.
| Component | Fuel Injector -- electrical harness connector terminals | Engine Control Module (ECM) -J623- electrical connector T60 terminals |
|---|---|---|
| Cylinder 1 Fuel Injector -N30- | 1 | 2 |
| 2 | 33 | |
| Cylinder 2 Fuel Injector -N31- | 1 | 17 |
| 2 | 32 | |
| Cylinder 3 Fuel Injector -N32- | 1 | 1 |
| 2 | 47 | |
| Cylinder 4 Fuel Injector -N33- | 1 | 16 |
| 2 | 48 |
Specified value: 1.5 Ω Max.
If the specified value was Not obtained:
-- Check the wiring for an open, high resistance or short to ground.
-- Check the electrical harness connector for damage, corrosion, loose or broken terminals.
-- If necessary, repair the faulty wiring connection.
If the specified value was obtained:
-- Replace the Engine Control Module (ECM) -J623-.
-- Install the engine cover with air filter.
Final procedures
After the repair work, the following work steps must be performed in the following sequence:
- Check the DTC memory. Refer to DIAGNOSTIC MODE 03 - READ DTC MEMORY .
- If necessary, erase the DTC memory. Refer to DIAGNOSTIC MODE 04 - ERASE DTC MEMORY .
- If the DTC memory was erased, generate readiness code. Refer to READINESS CODE .