DTC Troubleshooting: P0234
DTC P0234: Turbocharger Overboost Problem
NOTE:
Before you troubleshoot, review the general troubleshooting information.
If any of the DTCs listed below are stored at the same time as DTC P0234, troubleshoot those DTCs first, then recheck for P0234.
P0107, P0108: MAP sensor
P0237, P0238: Turbocharger boost sensor

DTC Description
Confirmed DTC
Pending DTC
P0234 Turbocharger Overboost Problem
    

1.
Problem verification:

Problem verification
?1.
Turn the vehicle to the ON mode.

?2.
Clear the DTC with the HDS.


?3.
Turn the vehicle to the OFF (LOCK) mode.

?4.
Start the engine.

?5.
Hold the engine speed at 3,000 rpm without load (in P or N) until the radiator fan comes on.

?6.
Test-drive the vehicle under the same conditions with the on-board snapshot of this DTC is recorded.
Signal
Current conditions
Values
Unit
VEHICLE SPEED
    
ECT SENSOR 1
    
MAP SENSOR (HI RES)
    
TC BOOST PRESSURE
    
ENGINE SPEED
    

?7.
Check for Pending or Confirmed DTCs with the HDS.
DTC Description
Confirmed DTC
Pending DTC
P0234 Turbocharger Overboost Problem
    

Is DTC P0234 indicated?

     
YES
     
     
     
Go to step 2.
     
NO
     
     
     
Intermittent failure, the system is OK at this time. Check for poor connections or loose terminals at the turbocharger and the PCM. If the on-board snapshot of this DTC is recorded, try to reproduce the failure under the same conditions with the on-board snapshot.?
2.
Turbocharger wastegate control actuator check:

Turbocharger wastegate control actuator check
?1.
Select the Electric Waste Gate in the INSPECTION MENU with the HDS.

  

?2.
Visually inspect the operation of the turbocharger wastegate control actuator.

Does the turbocharger wastegate control actuator operate?

     
YES
     
     
     
Check for any authorized service information related to the DTCs or symptoms you are troubleshooting, or substitute a known-good PCM.?
     
NO