P0068: MAP/MAF - Throttle Position Correlation. Meaning, possible symptoms and checks before repair.
Meaning, symptoms, causes and checks
The controller finds an implausible relationship between throttle position and load derived from MAF airflow or MAP pressure. This is a correlation check and does not identify a failed sensor by itself. An intake leak or inaccurate input can disturb the expected relationship.
Affected system: Powertrain
Symptoms
- Engine warning light; a fallback operating mode is possible.
- Uneven idle, hesitation or reduced power, depending on the control strategy.
Possible causes
- Intake leak or disconnected duct, depending on the installation.
- Inaccurate MAP/MAF or throttle-position input; damaged electrical connections.
What to check
- Save operating conditions and address accompanying MAP, MAF or throttle electrical codes first.
- Inspect ducts between the filter, throttle and manifold, including PCV connections; use an approved leak-check method.
- Log RPM, throttle position and MAP/MAF together at idle and light acceleration; use application-specific reference data.
- When an input appears implausible, test its supply, ground and signal circuit before condemning the throttle body.
- After repair, clear codes and recheck signal correlation under the original recorded conditions, following the manufacturer’s procedure.
Also written as: P0068-00, P006800, PO068 (some scan tools add the fault-type byte, e.g. -00).