OBD-II code · Powertrain (generic, extended)
P26D5 Engine Coolant Pump Supply Voltage Circuit High
The dedicated supply voltage to the coolant pump module is above operating range. Wiring faults of this kind typically come from chafing, water ingress at connector seals, or pin push-back — a wiggle test on the harness while the code is active often confirms the location.
Is it safe to drive with P26D5?
Usually safe to drive in the short term. Get it diagnosed when convenient, sooner if the car drives differently.
Common causes
- Most likelyAlternator regulator failed to limit output
- Less likelyWiring shorted to a higher-voltage circuit
- Less likelyConnector pins corroded - high contact resistance
Repair at a glance
- Difficulty
- Medium
- DIY friendly
- Best left to a mechanic
- Typical labour
- 1–3.5 h
- Emissions test
- Usually unaffected
- Parts involved
- Smart Coolant Pump Module, Supply Circuit, Charging System
Related codes
- P26D2Engine Coolant Pump Control Module Over Temperature
- P26D3Engine Coolant Pump Supply Voltage Circuit
- P26D4Engine Coolant Pump Supply Voltage Circuit Low
- P26D6Engine Coolant Pump Clutch Control Circuit / Open
- P26D7Engine Coolant Pump Clutch Performance/Stuck Off
- P26D8Engine Coolant Pump Clutch Stuck On
Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.