U069ELost Communication With Coolant Heater A
- Generic OBD-II code · Network
- How the car detects it
- Coolant heater A is an electric heater with its own control electronics that warms coolant for the cabin and, in some designs, for the traction battery – usually a high-voltage PTC unit in hybrids and EVs. The vehicle commands it over a data link, mostly LIN: DBK's 400 V heater is driven via LIN 2.0 plus a PWM input, and Webasto's 800 V range adds CAN on its larger models. U069E is stored when the commanding module stops getting answers from the heater. No manufacturer documents U069E publicly. The 2013–2014 Chevrolet Volt shows the layout with a separate coolant heater control module; GM diagnosed it with its own code B101D (PIC5943), and heat returned once the engine ran. Circuit and internal faults of this heater are P2B72–P2B75 and P2DA4–P2DA7. The driver mainly notices little or no heat in electric mode.
- What you may notice
- Little or no cabin heat in electric mode
- Engine starts more often in cold weather to supply heat (hybrids)
- Slow battery warm-up or reduced charging power in frost, where the heater serves the battery
- Likely causes
- LikelyLIN or CAN line to the heater broken, shorted or connector loose
- Possible12 V supply or ground of the heater electronics missing
- PossibleControl electronics inside the heater failed
- RareHeater or master module software fault
- Repair
- Medium · Usually a job for a workshop.Typical cost: €100 – €1,500
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.