Fuel Injectors, Checking
The following test procedure is used to diagnose all fuel injectors.
Special tools and workshop equipment required
- Multimeter.
- Diode test lamp (12 V).
- Wiring diagram.
Test requirements
- The Fuel Pump relay is operational.
- The Engine Speed (RPM) Sensor -G28- 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 with air filter. Refer to the Repair information.
-- Disconnect the Fuel Injector -- electrical harness connectors from Fuel Injectors -N30, N31, N32, N33, N83-.
Checking internal resistance
-- Using a multimeter, check the Fuel Injector -- electrical terminals 1 to 2 for resistance.
Specified value: 10.0 to 18.5 Ω (at approx. 20° C)
If the specified value was Not obtained:
-- Replace the malfunctioning Fuel Injector -- Refer to the Repair information.
If the specified value was obtained:
Checking activation and wiring
-- Connect a Diode test lamp (12 V) 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 Fuel Pump Relay -J17-.
-- Connect a jumper between the Fuel pump relay terminals 30 and 87
-- Turn the ignition switch ON.
-- Using a test lamp connected to ground, check terminal 1 of the Fuel Injector -- to be tested. The lamp should be ON.
-- If the test lamp did not turn on, locate the open or high resistance in the voltage supply circuit.
If the voltage supply was OK:
If the manufacturers test box is being used, perform the following step.
-- Install the test box.
If the manufacturers test box is not being used, perform the following step.
-- Remove the Engine Control Module (ECM) -J623-. Refer to the Repair information.
-- 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. Refer to Wiring Diagrams for pin locations.
| Component | Fuel Injector -- electrical harness connector terminals | Engine Control Module (ECM) -J623- electrical connector T60 terminals or test box sockets |
|---|---|---|
| Cylinder 1 Fuel Injector -N30- | 2 | 2 |
| Cylinder 2 Fuel Injector -N31- | 2 | 3 |
| Cylinder 3 Fuel Injector -N32- | 2 | 18 |
| Cylinder 4 Fuel Injector -N33- | 2 | 19 |
| Cylinder 5 Fuel Injector -N83- | 2 | 17 |
Specified value: 1.5 Ω Max.
If the specified value was Not obtained:
-- Check the wiring for an open, high resistance or short to voltage or ground.
-- Check the electrical harness connector for damage, corrosion, loose or broken terminals.
-- If necessary, repair the faulty wiring.
If no malfunction is detected in the wiring and If the voltage supply was OK:
-- Replace the Engine Control Module (ECM) -J623-. Refer to the Repair information.
-- Install the engine cover with air filter. Refer to the Repair information.
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 .