P0C4CHybrid/EV Battery Pack Coolant Pump A Supply Voltage Circuit Low
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- Can trigger limp mode
- How the car detects it
- P0C4C reports that the supply voltage reaching battery coolant pump A is below the expected level while the circuit is not fully open. Typical reasons are high resistance in the feed, a corroded fuse contact, a weak relay, a poor ground or a short to ground that drags the line down. No manufacturer documents P0C4C publicly. Ford uses the sibling P0C4B for the open supply circuit on its 2020 Escape, Explorer and Aviator hybrids, and Bentley's bulletin on P0C4700 for 2025–2026 Continental GT and Flying Spur hybrids shows what such a feed contains: a 10 A fuse, a relay and a harness route that can chafe at the rear suspension. CARB requires the electrical parts of battery thermal management to be monitored. A pump that receives too little voltage runs slowly or not at all.
- What you may notice
- MIL or hybrid or EV warning
- Coolant pump running slowly or intermittently
- Battery power reduced when the pack warms up
- Likely causes
- LikelyHigh resistance from corroded fuse, relay contacts or connector
- PossiblePoor pump ground connection
- RareSupply wire chafed and shorted to ground
- 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 – €600
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.