DTC Troubleshooting

DTC P0234: Turbocharger Overboost Problem

NOTE:
- Before you troubleshoot, record all freeze data and any on-board snapshot, and review the general troubleshooting information.
- If any of the DTCs listed below are indicated at the same time as DTC P0234, troubleshoot those DTCs first, then recheck for P0234.

P0107, P0108, P1128, P1129: Manifold absolute pressure (MAP) sensor.
P0236, P0237, P0238: Turbocharger boost sensor.

1. Turn the ignition switch ON (II).
2. Clear the DTC with the HDS.
3. Select the TURBOCHARGER WASTEGATE CONTROL SYSTEM TEST in the INSPECTION MENU with the HDS.

Is the result OK?

YES - Intermittent failure, the system is OK at this time.

NO - Go to step 4.

4. Select TURBOCHARGER WASTEGATE CONTROL SOLENOID VALVE ON in the INSPECTION MENU with the HDS.

Do you hear the solenoid operating?

YES - Go to step 5.

NO - Replace the turbocharger wastegate control solenoid valve, then go to step 10.

5. Turn the ignition switch OFF.
6. Remove the charge air cooler.




7. Check for poor connections, blockage, or damage at these parts:
- Hose (A) between the turbocharger wastegate control solenoid valve and the turbocharger wastegate control actuator
- Hoses (B) and pipe (C) between the turbocharger wastegate control solenoid valve and turbocharger
- Turbocharger port (D)

Are the parts OK?

YES - Go to step 8.

NO - Repair or replace any damaged parts, then go to step 9.

8. Inspect the turbocharger wastegate control solenoid valve.

Is the solenoid valve OK?

YES - Check the turbocharger and turbocharger wastegate control actuator, make any necessary repairs, then go to step 9.

NO - Replace the turbocharger wastegate control solenoid valve, then go to step 9.

9. Reinstall the charge air cooler.
10. Turn the ignition switch ON (II).
11. Reset the PCM with the HDS.
12. Do the PCM idle learn procedure.
13. Start the engine. Hold the engine speed at 3,000 rpm without load (in Park or neutral) until the radiator fan comes on, then let it idle.
14. Test-drive under these conditions:
- ECT SENSOR 1 above 158 °F (70 °C)
- Transmission in D position
- Engine speed above 3,800 rpm
- REL TP SENSOR above 59 deg
- Drive at least 2 seconds

15. Check for Temporary DTCs or DTCs with the HDS.

Is DTC P0234 indicated?

YES - Make sure the turbocharger wastegate control solenoid valve, connecting hose, and port are OK, then go to step 1.

NO - Troubleshooting is complete. If any other Temporary DTCs or DTCs are indicated, go to the indicated DTCs troubleshooting.