P0A9A code meaning
Hybrid/EV Battery Pack Cooling Fan 2 Control Circuit High
Powertrain system Generic code P0Axx codes Check engine light
What P0A9A means
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.
P0A9A at a glance
- Check engine lightYes, usually on
- Emissions testCan fail
- Limp modePossible
- Repair difficultyMedium
- Typical labor0.5 to 3 hours
- Clears after repairWhen cleared with a scanner
Symptoms of P0A9A
- Check engine or hybrid warning
- Fan 2 runs constantly or not at all
- Possible 12 V battery drain when parked
Common causes of P0A9A
- Most likelyFan 2 control wire shorted to supply voltage
- PossibleFan 2 control input internally open or shorted to supply
- Less likelyCorroded connector with leakage to supply
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Hybrid battery cooling fan 2Wiring harnessBms
What each part of P0A9A means
| P | Powertrain system: engine, fuel system, ignition, emissions and transmission. |
| 0 | Generic code: it means the same on every make (SAE standard). |
| A | Area: hybrid propulsion. |
| 9A | The exact fault in that area. |
What to do next
- Note P0A9A and any other codes stored with it: several codes together often point to one cause.
- Check for loose connectors and damaged wiring around the parts the code names.
- Check open recalls for your car: some faults are fixed for free by the dealer. Enter your VIN.
- Clear the code only after the repair. If it comes back, the fault is still there.
Buying a used car? Scan it for stored codes before you pay. A recently cleared memory can hide a problem.
Questions about P0A9A
What does P0A9A mean?
P0A9A means "Hybrid/EV Battery Pack Cooling Fan 2 Control Circuit High". P0A9A reports a short to voltage on the control circuit of the second battery cooling fan. It is a generic code, so it means the same on every make.
Is it safe to drive with P0A9A?
Drive gently and only to a workshop. With P0A9A the car can go into limp mode (reduced power) to protect itself.
Will P0A9A fail an emissions test?
Yes, it can. P0A9A is emissions-related, so most inspection programs fail a car while it is stored or while the check engine light is on.
How hard is P0A9A to fix?
Difficulty: medium. A typical repair takes 0.5 to 3 hours of work. This is a job for a workshop.
Will P0A9A clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.