P0D64Hybrid/EV Battery Pack Cooling Fan Enable 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
- Besides its speed command, a battery cooling fan can have a separate enable line that switches the fan electronics on. P0D64 means the controller has found this enable output open. GM documents it in its hybrid OBD tables 16OBDG02 to 19OBDG02 under the battery system module, there named fan 1 enable: with the enable commanded off and system voltage above 10.2 V, an output voltage stuck between 1.14 and 2.81 V counts as an open circuit, and 16 failures in 20 samples at 250 ms set it as Type B, MIL after two trips. The fan speed diagnostic P0BC8 is suspended while P0D64 to P0D66 are active. Typical causes are a broken wire or an unplugged fan connector. Without enable the fan stays off, so the battery heats faster and power may be reduced. Short to ground is P0D65, short to voltage P0D66.
- What you may notice
- Check engine light or hybrid warning after two trips
- Battery cooling fan does not run
- Reduced electric assist when the battery gets hot
- Likely causes
- LikelyBroken enable wire between battery controller and fan
- PossibleFan connector unplugged or not latched, often after battery or trim work
- PossibleOpen enable input inside the fan electronics
- RareEnable driver in the battery system module defective
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Medium · Often possible to do yourself.Typical cost: €30 – €500
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.