Intake Manifold Runner Control Stuck Closed (Bank 1)
The IMRC flap on bank 1 is stuck in the closed position and cannot open at higher rpm. Top-end power suffers because the runner is restricted, and the engine may breathe poorly above mid-range.
Affected components
- Intake manifold runner
- Imrc actuator
Common causes
- High likelihood: Carbon deposits seize flap closed
- Medium likelihood: Actuator stuck or vacuum line collapsed
- Low likelihood: Carbon or debris buildup preventing free movement
Diagnostic notes
- The malfunction indicator lamp may illuminate
- This code can affect emissions
- A drive cycle may be required after repair
Related codes
Sources
Diagnostic information is provided for reference only. Confirm the code with a compatible scan tool and follow the vehicle manufacturer's service procedures before replacing components.