Fault Diagnosis, Injectors

Fault Diagnosis, Injectors:

FAULT DIAGNOSIS, INJECTORS

Symptom of fault
The engine is running on 3 cylinders.

Diagnostic procedure
1. Connect an ISAT scan tool.

- Ignition switched ON.
- Select each individual valve in the ISAT menu "ACTIVATE" with the submenu "INJECTORS".

The valve is activated for 10 seconds at 10 Hz. If a longer activation time is required, the command must be repeated.

- Listen for the sound of each individual injector operating.
- If all the injectors are working, continue with step 5.
- If any injector is not working, continue with step 2.

Fault Diagnosis, Injectors:

2. Unplug the connector of the injector concerned.

- Connect the test lamp to the injector's connector (female).
- Activate the injector concerned with the ISAT scan tool and the activating command "INJECTOR CYL 1, 2, 3 or 4".

The test lamp must flash at a frequency of 10 Hz for 10 seconds. Repeat the command in the event of uncertainty.

- If the test lamp flashes, continue with step 4.
- If the test lamp does not flash, continue with step 3.

3. Check that the relevant injector receives a 12 V supply.

- Measure the voltage by connecting the voltmeter between the connector of the relevant injector, pin 1 and Batt -.
- Activate the relevant injector with the ISAT scan tool and the activating command "INJECTOR CYL 1,2,3 or 4."

The voltmeter must show approx. 12 V.

- If the voltage is incorrect, the fault is located in the lead between pin 1 and crimped connection J67.
- If the voltage is correct, check the lead between pin 2 and the relevant ECM output.

Fault Diagnosis, Injectors:

4. Check the resistance of the relevant injector.

- Measure resistance in the injectors connector between pins 1 and 2.

The nominal resistance is 12 ± 0.35 Ohms at 20° C.

- If the resistance is incorrect, install a new injector.
- If the resistance is correct, continue with step 5.

5. Measure flow.

- If the flow measurement is incorrect, install a new injector.
- If the flow measurement is correct, continue with step 6.

6. Drive the car to check whether the fault symptoms persist.

- If so, continue at "Procedure before replacing ECM".