P26D5Engine Coolant Pump Supply Voltage Circuit High
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- How the car detects it
- P26D5 is set when the power feed of the engine coolant pump carries a higher voltage than the system allows. No manufacturer documents this code in public. It belongs to the same supply group as P26D3 and P26D4; Ford's hybrid OBD summaries explain the supply logic on the general code, and CARB requires electrical faults of monitored components to be detected. A high feed voltage can stem from an overcharging alternator or DC/DC converter, a jump start from a 24 V source, or a sensing line shorted to another powered circuit. In some designs a feed that stays live after shutdown, for example because of a stuck relay, is also judged as high. The pump electronics may switch off to protect themselves, and other modules often log overvoltage codes at the same time.
- What you may notice
- Check engine lamp on
- Overvoltage codes in other control modules
- Likely causes
- PossibleOvercharging alternator or DC/DC converter
- PossibleSupply relay stuck closed so the feed stays live
- RareFeed or sensing wire shorted to another powered circuit
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Medium · Usually a job for a workshop.Typical cost: €20 – €900
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.