Fuel Metering Valve, Checking

Fuel Metering Valve, Checking

Special tools, testers and auxiliary items required
- Multimeter.
- Wiring diagram.

Test requirements
- The Engine Control Module (ECM) J623 fuses OK.
- The fuel filter OK.
- The battery voltage at least 12.5 V.
- All electrical consumers switched off (radiator fan must NOT run during test).
- A/C switched off.
- The fuel tank at least 1 / 4 filled.
- The ignition switched off.

Test procedure
- Perform a preliminary check to verify the customers complaint. General Diagnosis

Start diagnosis







- Remove engine cover - arrows -.

Checking resistance







- Disconnect the Fuel Metering Valve N290 electrical harness connector - 2 -.







- Using a multimeter , check the Fuel Metering Valve N290 terminals 1 to 2 for resistance.
- Specified value: 25 to 35 Ohms (at approx. 20 degrees C)

If the specified value was not obtained:
- Replace the Fuel Metering Valve N290.

If the specified value was obtained:

Checking voltage
Switch the ignition on.







- Using a multimeter , check the Fuel Metering Valve N290 electrical connector terminal 1 to Ground (GND) for voltage.

Specified value: battery voltage.

Switch the ignition off.

If the specified value was not obtained:
- Check the wiring from the Fuel Metering Valve N290 electrical connector terminal 1 to the Engine Component Power Supply Relay J757 socket 2/87 for an open circuit, a short circuit to each other, Battery (+), and Ground (GND).
- Check the electrical harness connector for damage, corrosion, loose or broken terminals.
- If necessary, repair the wiring connection.

If no malfunctions are found in the wiring:

Checking wiring

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.







- Using a multimeter , check the Fuel Metering Valve N290 electrical harness connector terminals to the Engine Control Module (ECM) J623 electrical harness connector T60 terminals for resistance.

Fuel Metering Valve N290 Engine Control Module (ECM) J623
electrical harness connector electrical harness connector T60
terminal terminal or test box socket
2 19

Specified value: 1.5 Ohms Max.

If the specification was not obtained:
- Check the wiring for an open circuit, a short circuit to each other, Battery (+), and Ground (GND).
- Check the electrical harness connector for damage, corrosion, loose or broken terminals.
- If necessary, repair the faulty wiring connection.

If no malfunction is detected in the wiring:
- Erase the DTC memory. Diagnostic Mode 04 - Erase DTC Memory
- Perform a road test to verify repair.

If the DTC does not return:

Repair complete, Generate readiness code. Monitors, Trips, Drive Cycles and Readiness Codes
- End diagnosis.

If the DTC does return and no malfunction is detected in the wiring and the voltage supply was OK:
- Replace the Engine Control Module (ECM) J623.
- Assembly is performed in the reverse of the removal.

Final procedures
After repair work, the following work steps must be performed in the mentioned sequence:
1. Check the DTC memory. Diagnostic Mode 03 - Read DTC Memory
2. If necessary, erase the DTC memory. Diagnostic Mode 04 - Erase DTC Memory
3. If the DTC memory was erased, generate readiness code. Monitors, Trips, Drive Cycles and Readiness Codes

End of diagnosis