P0D65: Hybrid/EV Battery Pack Cooling Fan Enable Circuit Low

P0D65 reports a short to ground on the enable output of the battery cooling fan: the line stays low even though the controller is trying to switch the fan on. GM's 2013 eAssist mild hybrid table 13OBDG05C detects it from the output driver's fault flag for the power pack fan, 20 failures in 25 samples at 250 ms, Type B. The later hybrid tables 16OBDG02 to 19OBDG02 test it with the enable commanded on: a voltage under 5.35 V at system voltage above 10.2 V counts, and 16 failures in 20 samples set the code, again Type B with MIL after two trips. A chafed wire touching the body or a shorted input inside the fan are the usual finds. The fan cannot start, so expect higher battery temperatures and possibly reduced electric support. Open circuit is P0D64, short to voltage P0D66.

High severity. Can I keep driving?If the car still runs, drive as little as possible and go to a specialized repair shop. Do not touch the orange cables: they carry high voltage.

Symptoms

Check engine light or hybrid warning after two trips
Battery cooling fan never switches on
Engine runs more and electric assist drops in hot weather

Most likely causes

Enable wire chafed and shorted to body ground
Shorted enable input inside the fan electronics
Moisture or corrosion bridging the enable pin to ground
Enable driver in the battery controller defective

What to check, in order

Start with the simplest. You can tick off each step.

Read the codes with a hybrid-compatible scanner and write down the freeze frame data
With the connector unplugged, check whether the signal wire is making contact with ground.
Make sure the battery cooling air intake is clean
Check the 12 V auxiliary battery, which can also trigger warnings
Leave any high-voltage measurements to a specialized repair shop

Good to know

Repair difficulty: medium
It can trigger limp mode.
It affects emissions.

What each character of P0D65 means

P: Powertrain: engine and transmission
0: Generic code: same on every make
D: Subsystem depends on the code range
65: Specific fault in that system

Frequently asked questions

Can I keep driving with code P0D65?

If the car still runs, drive as little as possible and go to a specialized repair shop. Do not touch the orange cables: they carry high voltage.

What causes code P0D65?

The most common causes are: enable wire chafed and shorted to body ground; shorted enable input inside the fan electronics; moisture or corrosion bridging the enable pin to ground.

Related codes

Sources

Values and procedures vary by manufacturer. If it affects brakes, steering, fuel or high voltage, see a professional. Updated: 2026-11-04. How we build these pages.