P2B31: Fan 2 Performance/Stuck Off

What it means

Cooling fan 2 is commanded on but does not produce the expected airflow. Mechanical seizure, broken motor, or relay failure.

At a glance

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

How it works

Cooling Fan 2 provides additional airflow through the radiator and condenser when the control module requests it. This code sets when Fan 2 is commanded on but does not produce the expected airflow, often because its motor has failed, its relay cannot switch, or its blades are obstructed.

Common causes

Most likely first.

1. Fan motor seized or burned out
2. Fan relay contacts oxidised
3. Carbon or debris buildup preventing free movement

Symptoms

• Check-engine or temperature warning light
• Engine temperature rises, especially at low speed or idle
• Air conditioning may cool poorly

How to diagnose it

1. Review freeze-frame data and fan command status to verify that Fan 2 was requested to run when the fault set.
2. With the vehicle safely switched off, inspect Fan 2 specifically for debris, damage, or binding that prevents its blades from turning freely.
3. Check Fan 2's fuse, relay, connector, and wiring for corrosion, looseness, damage, or overheating.
4. Use a scan tool to command Fan 2 on and check whether it turns and moves air; keep hands clear because it can start unexpectedly.
5. If its supply and control circuit are intact, test the Fan 2 motor and relay against the manufacturer's specification.

Common fixes

• Remove debris or obstruction preventing Fan 2 from turning.
• Repair a loose or corroded Fan 2 connector or wiring fault.
• Replace a faulty Fan 2 relay.
• Replace the Fan 2 motor if it is seized or fails testing.

Can I keep driving?

Avoid heavy traffic and prolonged idling, and stop if the temperature warning appears or the engine begins to overheat. Continued overheating can cause severe engine damage, so arrange prompt repair before driving further.