P2D40 code meaning
Hybrid/EV Battery Cooling System C Performance
Powertrain system Generic code P2Dxx codes Check engine light
What P2D40 means
P2D40 is the functional check of the third cooling path of the traction battery. Ford uses it for the refrigerant chiller on the 2020–2023 Explorer, Aviator and Police Interceptor Utility hybrids (FHEV and PHEV); the code is stored in the secondary OBD module SOBDMC and lights the MIL. Bulletin 22-2342 tests the path: after the pack has warmed to at least 18 °C, maximum chiller flow is commanded for 2 minutes and the inlet coolant must drop by 3 °C; otherwise cooler fins, coolant pump and diverter valve are checked. On the road the chiller should engage above about 51 °C battery temperature on FHEV and 42 °C on PHEV. Ford lists squeezed hoses, trapped air, a refrigerant charge under 80 % of specification or a partly blocked cooler; SSM 51297 points to an updated workshop procedure. Other paths are P0C32 and P2D3F.
P2D40 at a glance
- Check engine lightYes, usually on
- Emissions testCan fail
- Limp modePossible
- Repair difficultyHard
- Typical labor1 to 5 hours
- Clears after repairAfter a drive cycle
Symptoms of P2D40
- Malfunction indicator lamp on
- Battery temperature rises during hard driving or towing, power may be reduced
- Weak cabin air conditioning if the refrigerant charge is low
Common causes of P2D40
- Most likelyLow refrigerant charge in the A/C circuit feeding the battery chiller
- PossibleAir in the coolant or pinched, kinked battery coolant hoses
- PossiblePartly blocked battery chiller (high voltage battery cooler)
- PossibleCoolant diverter valve or battery coolant pump not delivering flow through the chiller
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Hv battery cooling system cBattery pack coolant loop
What each part of P2D40 means
| P | Powertrain system: engine, fuel system, ignition, emissions and transmission. |
| 2 | Generic code (second SAE range): it means the same on every make. |
| 40 | The exact fault in that area. |
What to do next
- Note P2D40 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 P2D40
What does P2D40 mean?
P2D40 means "Hybrid/EV Battery Cooling System C Performance". P2D40 is the functional check of the third cooling path of the traction battery. It is a generic code, so it means the same on every make.
Is it safe to drive with P2D40?
Drive gently and only to a workshop. With P2D40 the car can go into limp mode (reduced power) to protect itself.
Will P2D40 fail an emissions test?
Yes, it can. P2D40 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 P2D40 to fix?
Difficulty: hard. A typical repair takes 1 to 5 hours of work. This is a job for a workshop.
Will P2D40 clear itself after the repair?
After the repair the car has to complete a drive cycle (a mix of city and highway driving) before the test runs again. Until then the readiness monitor shows "not ready", which can fail an inspection.