DTC P0234
DTC P0234: Turbocharger Overboost Problem
General Description
The powertrain control module (PCM) controls the turbocharger boost pressure so that the boost pressure to the engine does not exceed the set upper pressure limit. When the boost pressure increases abnormally, a malfunction of the turbocharger control system is determined and fuel cut and throttle restriction control is done to protect the powertrain.
Monitor Execution, Sequence, Duration, DTC Type
| Execution | Continuous |
| Sequence | None |
| Duration | 1.0 second or more |
| DTC Type | One drive cycle, MIL on |
Enable Conditions
| Condition | Minimum | Maximum |
|---|---|---|
| Engine coolant temperature [ ECT Sensor 1] | 155.9 deg.F (68.8 deg.C) | - |
| Other | No change of boost pressure upper limit | |
| [ ]: HDS Parameter | ||
Malfunction Threshold
Either one of conditions is met for at least 1 second, and fuel cut-off is operated for engine protection.
- The boost pressure is 170 - 300 kPa (1276 - 2250 mmHg, 50.3 - 88.7 inHg) or more*
- The intake air pressure is 249.1 - 293.8 kPa (1868.6 - 2203.4 mmHg, 73.63 - 86.82 inHg) or more*
*: Varies with driving conditions.
Possible Cause
The causes shown may not be a complete list of all potential problems, and it is possible that there may be other causes
- Turbocharger wastegate control valve stuck close failure
- Turbocharger wastegate control actuator stuck close failure
- Turbocharger wastegate control valve bypass clogged
- PCM internal circuit failure (BARO sensor)
- Turbocharger boost sensor internal failure
Confirmation Procedure
Operating Condition
- Start the engine. Hold the engine speed [ Engine Speed] at 3000 RPM without load (in P or N) until the radiator fan comes on.
- Drive at engine speed [ Engine Speed] at 1500 RPM or more for at least 1 second.
- Drive the vehicle in this manner only if the traffic regulations and ambient conditions allow.
With the HDS
None.
Diagnosis Details
Conditions for setting the DTC
When a malfunction is detected, the MIL comes on and a Pending DTC, a Confirmed DTC, the freeze data, and the on-board snapshot are stored in the PCM memory.
Conditions for clearing the DTC
The MIL is cleared if the malfunction does not return in three consecutive trips in which the diagnostic runs. The MIL, the Pending DTC, the Confirmed DTC, the freeze data, and the on-board snapshot can be cleared with the scan tool Clear command or by disconnecting the 12 volt battery.