P0A9AHybrid/EV Battery Pack Cooling Fan 2 Control Circuit High
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- Can trigger limp mode
- How the car detects it
- P0A9A reports a short to voltage on the control circuit of the second battery cooling fan. No manufacturer publishes this exact code; CARB requires the electronic outputs of battery thermal management to be checked for circuit faults. The fan 1 counterpart P0A85 shows the usual method: GM samples the output while the fan is commanded between 11 % and 100 % duty and counts a voltage above 9 V as a failure, setting a Type B code after 16 of 20 samples. A fan 2 diagnosis would work the same way. Depending on the circuit design the fan runs constantly or stops responding; a constantly running fan can drain the 12 V battery. Open and low faults are P0A96 and P0A99; a mechanically stuck-on fan is P0A98.
- What you may notice
- Check engine or hybrid warning
- Fan 2 runs constantly or not at all
- Possible 12 V battery drain when parked
- Likely causes
- LikelyFan 2 control wire shorted to supply voltage
- PossibleFan 2 control input internally open or shorted to supply
- RareCorroded connector with leakage to supply
- 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: €60 – €700
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.