Fuel Metering Valve, Checking

Fuel Metering Valve, Checking

Observe all safety precautions: => [ Safety Precautions ] Safety Precautions

View clean working conditions: => [ Clean Working Conditions ] Clean Working Conditions

Prior to repair work, perform a preliminary check to verify the condition. Refer to => [ Preliminary Check ] Preliminary Check.

Use only gold-plated terminals when servicing any component with gold-plated electrical harness connector terminals.

For wiring diagrams, component locations, and connector views, Refer to the applicable wiring diagram.

Special tools, testers and auxiliary items required

• Multimeter

• Wiring diagram

Test requirements

• 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.

Start diagnosis

- Remove the engine cover.





- Disconnect the Fuel Metering Valve (N290) electrical harness connector.

Checking internal resistance

- Using a multimeter, check the Fuel Metering Valve (N290) terminals 1 to 2 for resistance.

Specified value: Near 3.2 ohms ( +/- 1 ohms)

If the specified value was Not obtained:

- Replace the Fuel Metering Valve (N290). Refer to the repair information.

If the specified value was obtained:

- Turn the ignition switch ON.

- Connect a multimeter red lead to terminal 2 of the Fuel Metering Valve (N290) and the black meter lead to ground and measure the voltage.

- Turn the ignition switch OFF.

Specified value: Battery voltage.

If the specified value was Not obtained:

- Check the circuit between terminal 2 of the Fuel Metering Valve (N290) and fuse SB14 in Fuse Panel B for an open, short or high resistance.

- Repair as necessary.

If the specified value was obtained:

- Turn the ignition switch ON.

- Connect a multimeter red lead to terminal 1 of the Fuel Metering Valve (N290) and the black meter lead to ground.

Specified value: Near 3.2 V (+/-.5 V).

- Turn the ignition switch OFF.

If the specified value was Not obtained:

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 Motronic Engine Control Module (ECM) (J623). Refer to the repair information.

- Using a multimeter, check the Fuel Metering Valve (N290) electrical harness connector terminal 1 to the Motronic Engine Control Module (ECM) (J623) electrical harness connector T60 terminal for a short to ground or voltage, high resistance or an open circuit.






Specified value: 1.5 ohms max.

If the specification is not obtained:

- Check the wires for a short circuit to each other, a short to battery voltage, and a short to ground.

- Check the electrical harness connector for damage, corrosion, loose or broken terminals.

- Repair as necessary.

If no malfunction is detected in the wiring and the voltage was not correct:

- Replace the Engine Control Module (ECM) (J623). Refer to the service information for procedures.

Final procedures

After repair work, the following work steps must be performed in the following sequence:

1. Check the DTC memory. Refer to => [ Diagnostic Mode 03 - Read DTC Memory ] Diagnostic Modes 01 - 0A.

2. If necessary, erase the DTC memory. Refer to => [ Diagnostic Mode 04 - Erase DTC Memory ] Diagnostic Modes 01 - 0A.

3. If the DTC memory was erased, generate readiness code. Refer to => [ Readiness Code ] Readiness Code.