Fault-Code Library · Turbocharging
P0234: Turbocharger overboost condition
Boost pressure exceeded the ECU's permitted target for the operating condition.
Common symptoms
- •Reduced-power mode
- •Abrupt power loss
- •Boost surge
- •Engine warning light
Likely causes
- •Sticking turbo vanes or wastegate
- •Faulty boost-control valve
- •Restricted vacuum control
- •Incorrect pressure signal
First checks
- •Compare requested and actual boost
- •Inspect vacuum lines and actuator travel
- •Check charge-pressure sensor plausibility
Important
Do not continue repeated full-load testing until boost control is understood.
A fault code identifies a detected condition, not a failed part. Confirm manufacturer-specific subcodes and live data.