P0AD1: Hybrid/EV Battery Pack Cooling Fan 3 Stuck On

What it means

The HV battery pack cooling fan 3 reports a stuck on condition. Battery thermal management is impaired.

At a glance

• Usually lights the check-engine light
• The engine or gearbox may go into limp mode

How it works

Battery cooling fan 3 moves air through the hybrid or EV battery pack when the control system requests cooling. This code sets when fan 3 continues running after it should be off, indicating that its relay, control circuit, driver, or fan wiring may be keeping it powered.

Common causes

Most likely first.

1. Fan relay or control circuit stuck on
2. Fan control module or driver fault
3. Cooling fan motor or wiring fault

Symptoms

• EV/hybrid system warning light on
• Reduced power output or limp mode
• Charging may fail or be slowed
• Reduced electric range

How to diagnose it

1. Use a scan tool to compare the fan 3 command with its actual operation and note whether the fan remains on after the command ends.
2. Inspect fan 3 wiring and connectors for damage or a short that could keep the fan energized.
3. Check the fan 3 relay and control circuit for contacts or signals stuck in the on state, following the wiring diagram.
4. Test the fan control module or driver and fan motor circuit according to the manufacturer's procedure.
5. Check related battery cooling codes and module data before replacing a control component.

Common fixes

• Repair wiring that is shorted or keeping fan 3 powered.
• Replace a fan 3 relay confirmed stuck on.
• Repair or replace a faulty fan control module or driver.
• Replace fan 3 if testing identifies an internal motor or wiring fault.

Can I keep driving?

A fan that runs continuously can drain the low-voltage battery and may signal a control fault affecting battery cooling. Avoid long trips if the fan stays on or the vehicle limits power, and have the fault diagnosed promptly.