P0ACFHybrid/EV Battery Pack Cooling Fan 3 Control Circuit/Open
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- Can trigger limp mode
- How the car detects it
- Air-cooled traction batteries can use several blowers; P0ACF belongs to the third one and means the battery controller sees an open or otherwise invalid control line while it drives fan 3. CARB 1968.2 (e)(15.2.3)(B) requires the electrical inputs and outputs of the battery thermal management to be monitored like other comprehensive components. No manufacturer publicly documents this code; GM shows the method on fan 1 (P0A81): it checks the control voltage on the driver output and needs 16 failures before a Type B code is stored. Fan 1 and fan 2 have their own sets P0A81 and P0A96. Without the third blower the pack heats up faster, and power is limited.
- What you may notice
- Hybrid or EV system warning light, often with check engine light
- Electric drive power reduced when the battery gets warm
- No fan noise from the battery area when cooling is expected
- Likely causes
- LikelyLoose, corroded or unplugged connector at fan 3
- PossibleBroken control wire between battery controller and fan 3
- PossibleFan motor or its built-in driver open internally
- RareFan output stage in the battery controller defective
- 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 – €600
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.