P0E16Hybrid/EV Battery Pack Coolant Heater B Control Circuit/Open
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- Can trigger limp mode
- How the car detects it
- 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.
- What you may notice
- Check engine light on
- Battery warms up slowly in cold weather
- Reduced charging power at low temperatures
- Likely causes
- LikelyBroken wire in the heater B command circuit
- LikelyLoose or corroded connector at heater B
- PossibleOpen element or electronics inside heater B
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Hard · Usually a job for a workshop.Typical cost: €80 – €1,500
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.