P26D2: Engine Coolant Pump Control Module Overtemperature

What it means

The engine coolant pump control module has detected an overtemperature condition.

At a glance

• Usually lights the check-engine light

How it works

The coolant pump control module operates the pump and monitors its own temperature. P26D2 is set when the module detects that it has become too hot, which may follow inadequate cooling, excessive electrical load, or heat generated at a poor connection.

Common causes

Most likely first.

1. Pump control module overheating from inadequate cooling
2. Excessive electrical load or internal module fault
3. Poor electrical connection causing excess resistance

Symptoms

• Check-engine light may be on
• Engine temperature may rise
• Cooling-system warning or reduced-power message may appear

How to diagnose it

1. Review freeze-frame data and live module temperature, pump command, and system voltage to determine when overheating occurs.
2. Inspect the pump module and its surrounding area for damage, blocked cooling paths, or signs of heat exposure.
3. Check the module connector, power, and ground connections for corrosion or looseness that could create resistance and heat.
4. Check whether the pump is drawing excessive current or is mechanically restricted, using the manufacturer's test procedure.
5. If wiring, cooling, and pump load are normal but module temperature still rises, test the control module according to the manufacturer's procedure.

Common fixes

• Repair corroded or loose module power and ground connections.
• Restore any blocked or damaged cooling path for the pump control module.
• Repair or replace a pump that is restricted or drawing excessive current.
• Replace the control module if it continues to overheat despite normal cooling and electrical load.

Can I keep driving?

Avoid driving if the engine temperature rises or a cooling warning appears, because an overheated module may reduce or stop pump operation. Stop safely if the engine overheats.