P0E16 code meaning
Hybrid/EV Battery Pack Coolant Heater B Control Circuit/Open
Powertrain system Generic code P0Exx codes Check engine light
What P0E16 means
P0E16 is the open-circuit code for a second battery coolant heater, B. Why a car has two: some thermal systems pair the pack heater with another heater, for example one for the cabin loop, and can route its heat to the battery. A patent from Magna E-Car describes exactly that fallback when the battery pack heater fails, so the letter depends on how the maker splits the heaters. No manufacturer documents P0E16 publicly, and none of the GM, Ford or Stellantis papers checked used it. The logic matches heater A, which GM's 2016 Volt checks as P1EC3 with 20 failures in 40 samples (Type B). CARB requires circuit monitoring of each output used to heat the energy store. Look for a broken wire, a loose connector or an open element. P0E17 and P0E18 are the shorts.
P0E16 at a glance
- Check engine lightYes, usually on
- Emissions testCan fail
- Limp modePossible
- Repair difficultyHard
- Typical labor1 to 4 hours
- Clears after repairWhen cleared with a scanner
Symptoms of P0E16
- Check engine light on
- Battery warms up slowly in cold weather
- Reduced charging power at low temperatures
Common causes of P0E16
- Most likelyBroken wire in the heater B command circuit
- Most likelyLoose or corroded connector at heater B
- PossibleOpen element or electronics inside heater B
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 heater bWiring harnessBms
What each part of P0E16 means
| P | Powertrain system: engine, fuel system, ignition, emissions and transmission. |
| 0 | Generic code: it means the same on every make (SAE standard). |
| 16 | The exact fault in that area. |
What to do next
- Note P0E16 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 P0E16
What does P0E16 mean?
P0E16 means "Hybrid/EV Battery Pack Coolant Heater B Control Circuit/Open". P0E16 is the open-circuit code for a second battery coolant heater, B. It is a generic code, so it means the same on every make.
Is it safe to drive with P0E16?
Drive gently and only to a workshop. With P0E16 the car can go into limp mode (reduced power) to protect itself.
Will P0E16 fail an emissions test?
Yes, it can. P0E16 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 P0E16 to fix?
Difficulty: hard. A typical repair takes 1 to 4 hours of work. This is a job for a workshop.
Will P0E16 clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.