Advanced Diagnostics

Advanced Diagnostics - 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 boost pressure control system is determined and fuel cut and throttle restriction control is done to protect the powertrain.

Monitor Execution, Sequence, Duration, DTC Type, OBD Status






Enable Conditions






Malfunction Threshold
- Powertrain protection high boost pressure determination.






- When the boost pressure (turbocharger boost sensor output or MAP sensor output) is at a specified pressure or more, and fuel cut for engine protection operates for at least 2.0 seconds, a malfunction is detected.






Driving Pattern
1. Start the engine. Hold the engine speed at 3,000 rpm without load (in P or N) until the radiator fan comes on.
2. Drive the vehicle with the engine at speed 3,800 rpm or more, and the throttle position at 58.8°or more, for at least 2 seconds.

- Drive the vehicle in this manner only if the traffic regulations and ambient conditions allow.

Diagnosis Details

Conditions for setting the DTC
When a malfunction is detected during the first drive cycle, a Pending DTC is stored in the PCM memory. If the malfunction returns in the next (second) drive cycle, the MIL comes on and a Confirmed DTC and the freeze data are stored.

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, and the freeze data can be cleared with the scan tool Clear command or by disconnecting the battery.