P20F8Intake Manifold Runner Control Circuit Performance (Bank 1)
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- How the car detects it
- P20F8 means the intake manifold runner or swirl flaps on bank 1 do not follow the commanded position, judged by comparing set point and feedback from the position sensor. Unlike P2004/P2006, which state a direction (stuck open or closed), this code reports poor tracking anywhere in the travel. GM's 2018 diesels set it when the tracking error exceeds 10 % in 80 of 100 samples, with coolant at 60 °C or more and the smart actuator powered for at least 5 s, as a Type B code; the 2025 diesel table 25OBDG04B uses the same 10 % limit over 960 of 1,200 counts for a DC swirl motor. Mazda found P20F8 on 2023–2025 Mazda3, CX-30, CX-5 and CX-50 caused by the swirl valve motor overheating from frequent actuation and fixed it with new PCM software (bulletin 01-003/26). Drivers notice the MIL and sometimes rough idle or weaker low-end torque.
- What you may notice
- Malfunction indicator lamp on
- Rough idle or hesitation at low speed
- Less torque at low engine speed
- Likely causes
- LikelyFlaps or shaft sticking from carbon and oil deposits (common on diesels with EGR)
- PossibleWorn or overheating actuator motor or failed position sensor
- PossibleControl software needing an update (Mazda bulletin 01-003/26)
- RareWiring or connector fault at the actuator
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Medium · Usually a job for a workshop.Typical cost: €80 – €900
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.