Advanced Diagnostics

Advanced Diagnostics - DTC P0299: Turbocharger Underboost Problem










General Description
A malfunction of the powertrain control module (PCM) is detected when boost pressure does not occur at the engine operating area where boost pressure should occur, and a DTC is stored.

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






Enable Conditions






Malfunction Threshold
The difference between the upper limit boost pressure output and the actual boost pressure output is 27 kPa (7.9 inHg, 200 mmHg) or more for at least 4.0 seconds.

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 speed 3,800 rpm or more, and the throttle position 58.8° or more for at least 4 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.