P26CB: Engine Coolant Pump Performance/Stuck Off

P26CB means the engine coolant pump does not deliver the expected work, typically because the impeller is blocked or turns too slowly. Ford's OBD summaries for hybrids let the pump's own electronics judge this from current and speed: too much current at too low a speed through four restart attempts is reported over LIN, and the PCM records P26CB after five seconds. Genesis campaign 916G (GV70 3.5 T, 2024–2025) replaces the electric pump of the water-cooled charge air cooler because a stuck impeller set P26CB. Jaguar Land Rover bulletin JLRTB02030NAS1 links it on Ingenium 2.0 L petrol engines to a switchable mechanical pump whose diverter shroud no longer moves, making the fans run at full speed. Toyota's A25A engines log it as speed stuck. Overheating protection may cut power.

Symptoms

• Check engine lamp on
• Cooling fans running constantly at high speed
• Rising engine temperature or reduced power

Most likely causes

• Seized or obstructed impeller in the electric pump
• Diverter shroud of a switchable mechanical pump not moving
• Worn pump motor or bearing drawing excessive current
• Engine module logic needing a software update

What to check, in order

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

1. With the engine cold, check the coolant level; never do this when the system is hot
2. Compare the reading with other engine data while varying the engine speed.
3. Check the actual temperature in live data
4. Make sure the fan comes on when it should
5. Check the thermostat and connector
6. Measure the sensor and replace it if its readings do not make sense

Good to know

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

What each character of P26CB means

• P: Powertrain: engine and transmission
• 2: Generic code: same on every make
• 6: Control modules and outputs
• CB: Specific fault in that system

Frequently asked questions

Can I keep driving with code P26CB?

Watch the temperature gauge. If it climbs or a warning appears, stop the car in a safe place and turn off the engine: overheating can cause serious damage.

What causes code P26CB?

The most common causes are: seized or obstructed impeller in the electric pump; diverter shroud of a switchable mechanical pump not moving; worn pump motor or bearing drawing excessive current.

Related codes

• P26CAEngine Coolant Pump Control Circuit/Open
• P26CEEngine Coolant Pump Overspeed/Air In System
• P26D2Engine Coolant Pump Control Module Over Temperature
• P2601Coolant Pump A Control Circuit Performance/Stuck Off
• P0217Engine Coolant Over Temperature Condition

Sources

• fordservicecontent.com: OBDSM1901 HEV
• static.nhtsa.gov: MC 11023282 0001
• static.nhtsa.gov: MC 10173508 0001
• static.nhtsa.gov: MC 10176705 9999

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.