P0E17Hybrid/EV Battery Pack Coolant Heater B Control 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
- P0E17 reports that the command signal to battery coolant heater B stays too low, most often from a short to ground between controller and heater. No manufacturer documents P0E17 publicly. Some designs give the second heater a different job, such as warming the cabin loop, and only borrow it for the pack when needed, as a Magna E-Car patent outlines; the wiring of heater B may then run through other areas than that of heater A. GM covers ground shorts of its battery heater command inside the broader code P1EC3 on the 2016 Volt (Type B), so an exact low-only threshold is not public. CARB requires circuit checks on heating outputs of the energy store. Chafing near brackets and water in the plug are the classic finds. Open circuit is P0E16, short to voltage P0E18.
- What you may notice
- Check engine light on
- Second heater does not support battery warm-up
- Slower charging in winter
- Likely causes
- LikelyHeater B command wire shorted to ground
- PossibleWater or coolant in the heater B connector
- RareInternal short at the control input of 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.