P2078: Intake Manifold Tuning (IMT) Valve Position Sensor/Switch Circuit High Ba… — what it means, the affected system and what to check before replacing parts.
Meaning, symptoms, causes and checks
Intake Manifold Tuning (IMT) Valve Position Sensor/Switch Circuit High Bank 1. Basic catalogue definition; diagnostic details have not yet been reviewed.
Affected system: Powertrain
Symptoms
- An engine warning may appear without immediate changes in how the vehicle drives.
- Uneven idle or reduced acceleration may occur on some vehicles.
Possible causes
- The electrical signal from the bank-1 manifold-tuning valve position sensor can be too high; this does not by itself mean the valve is physically open.
- Sensor damage, corroded connectors or damaged wiring may affect the signal.
- A sticking valve mechanism may also require checking if position feedback is inconsistent.
What to check
- Confirm P2078 and visually inspect the sensor wiring, connector and terminals.
- Measure the sensor circuit signal and supply against vehicle-specific specifications.
- Compare commanded valve movement with position feedback before considering sensor or actuator replacement.
Also written as: P2078-00, P207800 (some scan tools add the fault-type byte, e.g. -00).