P0A84Hybrid/EV Battery Pack Cooling Fan 1 Control Circuit Low
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- Can trigger limp mode
- How the car detects it
- The controller detects a short to ground on the control output of battery cooling fan 1. GM tests it while the fan is commanded at low duty: a circuit voltage below about 0.26 V counts as a failure, and 16 fails in 20 samples at 250 ms set a Type B code (MIL after two trips). Another GM hybrid program detects it through the output stage status flag (20 of 25 samples). Mitsubishi lists P0A84 in the BMU and PHEV ECU of the 2018–20 Outlander PHEV among codes caused by a frozen battery heater relay, so meaning can differ by maker. Open and high faults are P0A81 and P0A85. With the output pulled low the fan may not respond, the pack warms up and power can be reduced.
- What you may notice
- Check engine or hybrid warning after two trips
- Battery cooling fan does not follow commands
- Reduced hybrid power when the pack gets warm
- Likely causes
- LikelyFan control wire chafed and shorted to ground
- PossibleInternal short in the fan's control input
- RareMoisture or corrosion in the fan connector
- RareDefective output stage in the controller
- 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.