P20F8
Intake Manifold Runner Control Circuit Performance (Bank 1)
The IMRC actuator drive circuit on bank 1 is electrically OK but its current draw or duty-cycle response is outside the calibrated profile — typically a high-resistance solenoid winding or a partially shorted driver.
- Check engine light: Yes
- Emissions related: Yes
- Repair difficulty: medium
Common causes
Ordered by how often each turns out to be the cause.
- Solenoid winding ageing — resistance climbingCommon
Parts involved
- IMRC Actuator
- IMRC Harness
P20F8 is a generic OBD-II code defined by SAE J2012. Exact wording and diagnostic procedure vary by manufacturer and model. Code definitions are drawn from the public-domain OBDex dataset; the workshop notes are our own.