P0C4D code meaning
Hybrid/EV Battery Pack Coolant Pump A Supply Voltage Circuit High
Powertrain system Generic code P0Cxx codes Check engine light
What P0C4D means
P0C4D is the counterpart to P0C4C: the voltage measured on the supply of battery coolant pump A is higher than the controller allows. That can come from a feed wire shorted to another, more highly loaded circuit, from a relay that stays closed when the pump should be off, or from an overall excessive on-board voltage, for example a faulty DC/DC converter. No manufacturer documents P0C4D publicly. Ford's bulletins for the 2020 Escape, Explorer and Aviator hybrids name the sibling P0C4B for the open supply, and Bentley describes the feed of the same pump with fuse and relay for 2025–2026 hybrids. CARB requires the electrical components of battery thermal management to be monitored. If several modules log overvoltage at once, the 12 V supply is the more likely culprit than the pump circuit.
P0C4D at a glance
- Check engine lightYes, usually on
- Emissions testCan fail
- Limp modePossible
- Repair difficultyMedium
- Typical labor0.3 to 2.5 hours
- Clears after repairWhen cleared with a scanner
Symptoms of P0C4D
- MIL or hybrid or EV warning
- Coolant pump running although the system is switched off
Common causes of P0C4D
- PossibleSupply wire shorted to another voltage-carrying circuit
- PossiblePump relay sticking closed
- Less likelyExcessive 12 V system voltage from a faulty DC/DC converter
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Hv battery pack coolant pump aWiring harnessBms
What each part of P0C4D means
| P | Powertrain system: engine, fuel system, ignition, emissions and transmission. |
| 0 | Generic code: it means the same on every make (SAE standard). |
| C | Area: hybrid propulsion. |
| 4D | The exact fault in that area. |
What to do next
- Note P0C4D and any other codes stored with it: several codes together often point to one cause.
- Check for loose connectors and damaged wiring around the parts the code names.
- Check open recalls for your car: some faults are fixed for free by the dealer. Enter your VIN.
- Clear the code only after the repair. If it comes back, the fault is still there.
Buying a used car? Scan it for stored codes before you pay. A recently cleared memory can hide a problem.
Questions about P0C4D
What does P0C4D mean?
P0C4D means "Hybrid/EV Battery Pack Coolant Pump A Supply Voltage Circuit High". P0C4D is the counterpart to P0C4C: the voltage measured on the supply of battery coolant pump A is higher than the controller allows. It is a generic code, so it means the same on every make.
Is it safe to drive with P0C4D?
Drive gently and only to a workshop. With P0C4D the car can go into limp mode (reduced power) to protect itself.
Will P0C4D fail an emissions test?
Yes, it can. P0C4D is emissions-related, so most inspection programs fail a car while it is stored or while the check engine light is on.
How hard is P0C4D to fix?
Difficulty: medium. A typical repair takes 0.3 to 2.5 hours of work. This is a job for a workshop.
Will P0C4D clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.