P26D6
Engine Coolant Pump Clutch Control Circuit / Open
The mechanical clutch on a belt-driven coolant pump (used to disengage the pump for fast warm-up) cannot be driven. Pump always engaged so warm-up takes longer.
- Check engine light: Yes
- Emissions related: No
- Repair difficulty: medium
Symptoms
- Check engine or transmission warning light on
- Harsh, delayed, or missing shifts
- Possible limp mode (locked in one gear)
- Slipping or shuddering during gear changes
Common causes
Ordered by how often each turns out to be the cause.
- Open coil in clutch solenoidCommon
- Broken control wirePossible
Parts involved
- Coolant Pump Clutch
- Clutch Solenoid
- Wiring Harness
P26D6 is a generic OBD-II code defined by SAE J2012. Exact wording and diagnostic procedure vary by manufacturer and model. Code definitions are drawn from the public-domain OBDex dataset; the workshop notes are our own.