Turbocharger Recirculating Valve N249, Checking

Turbocharger Recirculating Valve N249, Checking

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

Test requirements
- Fuse SB32 OK.
- The Motronic Engine Control Module (ECM) Power Supply Relay 2 J670 OK.
- Battery voltage at least 12.5 volts.
- All electrical consumers such as, lights and rear window defroster, switched off.
- On vehicles with automatic transmission, selector lever in position "P" or "N".
- A/C switched off.
- Ground (GND) connections between engine/transmission/chassis OK.
- Ignition switched off.

NOTE: Voltage for the Turbocharger Recirculating Valve N249 is supplied by the Motronic Engine Control Module (ECM) Power Supply Relay 2 J670.

Test procedure
- Perform a preliminary check to verify the customers complaint. Preliminary Check

Start diagnosis
- Remove the engine cover with air filter.

Checking internal resistance







- Disconnect the Turbocharger Recirculating Valve N249 electrical harness connector - 2 -.







- Using a multimeter, check the Turbocharger Recirculating Valve N249 terminals 1 to 2 for resistance.

Specified value: 10 to 20 Ohms (at approx. 20 degrees C)

If the specification was not obtained:
- Replace the Turbocharger Recirculating Valve N249.

If the specification was obtained:

Checking Voltage supply







- Using a multimeter, check the Turbocharger Recirculating Valve N249 electrical harness connector terminal 1 to Ground (GND).

Turbocharger Recirculating Valve N249 Measure to
electrical harness connector terminal
1 Engine Ground (GND)

- Operate the starter briefly.

Specified value: battery voltage.

- Switch the ignition off.

If the specified value was not obtained:
- Check the wiring from the Turbocharger Recirculating Valve N249 electrical harness connector terminal 1 to the Motronic Engine Control Module (ECM) Power Supply Relay 2 J670 socket 2/87 for a open circuit or a short circuit to 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 Motronic Engine Control Module (ECM) J623.







- Using a multimeter, check the Turbocharger Recirculating Valve N249 electrical harness connector terminal 2 to Motronic Engine Control Module (ECM) J623 electrical harness connector T60 terminal 21 for an open circuit.

Turbocharger Recirculating Motronic Engine Control Module
valve N249 electrical harness (ECM) J623 electrical harness
connector terminal connector T60 terminal or test box socket
2 21

Specified value: 1.5 Ohms max.

If the specification is not obtained:
- Check the wiring for 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 and if the voltage supply was OK:
- Replace the Turbocharger Recirculating Valve N249.
- 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 Motronic Engine Control Module (ECM) J623.
- Assembly is performed in the reverse of the removal.

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