P0234-TURBOCHARGER OVERBOOST CONDITION
For a complete wiring diagram Refer to Section 8W
- When Monitored:
With the engine running and the ECM attempting to govern turbocharger boost pressure.
- Set Condition:
The Intake Air Temperature/Boost Pressure Sensor indicates actual turbocharger boost is greater than the ECM setpoint for 6.5 seconds.
| Possible Causes |
| INTERMITTENT DTC |
| INTAKE AIR RESTRICTION |
| INTAKE AIR LEAK |
| VACUUM HOSES/TUBES |
| BOOST PRESSURE ACTUATOR |
| TURBOCHARGER |
Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 9 - ENGINE - DIAGNOSIS AND TESTING)
Diagnostic Test
1. CHECK FOR ACTIVE DTCTurn the ignition on.
With the scan tool, clear DTCs in the Engine Control Module (ECM).
Test drive the vehicle.
With the scan tool, select View DTCs.
Is the status Active for this DTC?
Yes
- Go To 2
No
- Refer to the *CHECKING FOR AN INTERMITTENT DTC Diagnostic Procedure. (Refer to 9 - ENGINE - DIAGNOSIS AND TESTING)
2. CHECK FOR INTAKE AND EXHAUST SYSTEM RESTRICTIONS
NOTE: Damaged, restricted or poorly connected intake and turbocharger related tubes can cause this DTC to set.
Inspect all air intake, crankcase vent and turbocharger related hoses/tubes and connections.
Inspect the complete exhaust system for damaged, bent or clogged pipes that can cause exhaust system restrictions and excessive backpressure.
Were any problems found?
Yes
- Repair or replace as necessary.
- Perform the ECM Verification Test Ver. 1. (Refer to 9 - ENGINE - DIAGNOSIS AND TESTING)
No
- Go to 3
3. INTAKE AIR TEMPERATURE/BOOST PRESSURE SENSOR CIRCUIT RESISTANCE
Turn the ignition off.
Disconnect the ECM harness connectors.
Disconnect the Intake Air Temp/Boost Pressure Sensor harness connector.
Measure the resistance of the each of the Boost Pressure Sensor circuits (3 circuits) between the Intake Air Temp/Boost Pressure Sensor and ECM harness connectors.
Is the resistance below 10.0 ohms for each measurement?
Yes
- Go to 4
No
- Repair the Boost Pressure Sensor circuit(s) that measure above 10.0 ohms for an open.
- Perform the ECM Verification Test Ver. 1. (Refer to 9 - ENGINE - DIAGNOSIS AND TESTING)
4. CHECK THE BOOST PRESSURE SYSTEM
Refer to the CHECKING THE BOOST PRESSURE SYSTEM to check the boost pressure supply hoses, Boost Actuator and Turbocharger boost output.
With the scan tool, select View DTCs.
View repair.
Yes
- Repair as necessary.
- Perform the ECM Verification Test Ver. 1. (Refer to 9 - ENGINE - DIAGNOSIS AND TESTING)