Fuel Metering Valve 2, Checking

Fuel Metering Valve 2, Checking

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

Test requirements
- The Fuel Pump (FP) Control Module J538 OK.
- The Engine Component Power Supply Relay J757 OK.
- The Fuse S282 OK.
- The fuel filter OK.
- The parking brake engaged.
- The battery voltage at least 12.5 V.
- The selector lever of automatic transmission in position "P" or "N".
- 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







- Disconnect the Fuel Metering Valve 2 N402 electrical harness connector - arrow -.

Checking internal resistance







- Using a Multimeter , check the Fuel Metering Valve 2 N402 terminals for resistance

Specified value: 450 to 1000 Ohms.

If the specified value was not obtained:
- Replace the High Pressure Fuel Pump.

If the specified value was obtained:

Checking voltage
- Switch the ignition on.







- Using a Multimeter , check the Fuel Metering Valve 2 N402 electrical harness connector terminal 1 to Ground (GND) for voltage.
- Switch the ignition off.

Specified value: battery voltage.

If the specified value was not obtained:
- Check the wiring from the Fuel Metering Valve 2 N402 electrical harness connector terminal 1 to the Engine Component Power Supply Relay J757 terminal 2/87 for a short circuit to Ground (GND), or an open circuit.
- Check the electrical harness connector for damage, corrosion, lose or broken terminals.
- If necessary, repair the wiring connection.

If no malfunctions are found in the wiring:

Checking wiring connections

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) 2 J624.







- Using a multimeter , check the Fuel Metering Valve 2 N402 electrical harness connector terminal 2 to the Engine Control Module (ECM) 2 J624 electrical harness connector T60a terminal 35 for an open circuit.

Fuel Metering Valve 2 N402 Engine Control Module (ECM) 2
electrical harness connector J624 electrical connector T60a
terminal terminal or test box socket
2 19

Specified value: 1.5 Ohms Max.

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

If no malfunction is detected in the wiring:
- Replace the Engine Control Module (ECM) 2 J624.

Final procedures
After the repair work, the following work steps must be performed in the following 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.