Turbocharger Recirculating Valve, Checking
Turbocharger Recirculating Valve, Checking
Special tools, testers and auxiliary items required
• Multimeter.
• Wiring diagram.
Test requirements
• The Motronic Engine Control Module (ECM) (J623) fuses 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.
Test procedure
- Perform a preliminary check to verify the customers complaint. Refer to => [ Preliminary Check ] Preliminary Check
Start diagnosis
- Remove the engine cover with air filter. Refer to the appropriate service manual.
- Disconnect the connector -1- from the Mass airflow sensor (G70) , and remove the Air Filter Housing. Refer to appropriate service manual.
Checking internal resistance
- Disconnect the Turbocharger Recirculating Valve (N249) electrical harness connector- 1 -.
- Using a Multimeter, check the Turbocharger Recirculating Valve (N249) terminals 1 to 2 for resistance.
Specified value: 13.6 +/- 5 ohms (at room temp.)
If the specified value was not obtained:
- Replace the Turbocharger Recirculating Valve (N249). Refer to the appropriate service manual.
- Go to Final procedures
If the specified value was obtained:
Checking Voltage supply
- Using a Multimeter, check the Turbocharger Recirculating Valve (N249) electrical harness connector terminal 1 to Ground (GND).
- Switch Ignition ON.
Specified value: battery voltage.
- Switch the ignition OFF.
If the specified value was not obtained:
- Check for an open or grounded circuit between terminal 1 and fuse SB 7 in Fuse Panel B.
- Check the wiring connection for damage, corrosion, loose or broken terminals.
- If necessary, repair the faulty wiring connection.
- Repair the circuit and replace any open fuses.
- Go to Final procedures
If the specified value was obtained:
Checking wiring
- Remove the Motronic Engine Control Module (ECM) (J623). Refer to the appropriate service manual.
- 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 50 for an open circuit.
Specified value: 1.5 ohms max.
If the specified value was not obtained:
- Check the wiring connection for an open circuit, short circuit to Battery voltage or Ground
- Check the electrical harness connector for damage, corrosion, loose or broken terminals.
- If necessary, repair the faulty wiring connection.
- Go to Final procedures
If the specified value was obtained:
- With the Motronic Engine Control Module (ECM) Connectors still unplugged (J623). Refer to appropriate service manual.
- Use a Multimeter, Check the Turbocharger Recirculating Valve (N249) electrical harness connector terminal 2 to engine ground for continuity
- If Specified value is 1.5 ohms or less
- Check the wiring connection for a short circuit to Engine Ground
- If necessary, repair the faulty wiring or connection.
- If no faults were found Replace the Motronic Engine Control Module (ECM) (J623). Refer to appropriate service manual.
Final procedures
- Reinstall the engine cover and air filter housing, if necessary. Refer to the appropriate service manual.
- After the 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 ] Programming and Relearning.