P2DA4Coolant Heater A Internal Control Module Performance
- Generic OBD-II code · Powertrain
- How the car detects it
- Coolant heater A here is an electric heater with built-in electronics, usually a high-voltage PTC or wire-element unit that warms coolant for cabin and battery in hybrids and EVs; it is separate from the engine block heater codes P01E8 ff. P2DA4 says that heater's own controller has found a fault in itself – a power switch that shorted, a temperature or current measurement that fails, or a processor error. Texas Instruments describes the usual layout: one controller on the 12 V side for LIN or CAN, one on the HV side that drives the elements and cross-checks current, voltage and temperature. No manufacturer documents P2DA4 publicly; Ford stores the sister code P2DA6 in the module SOBDMC on the F-150 Lightning. The heater is switched off, so expect little heat in electric mode.
- What you may notice
- Little or no cabin heat in electric mode
- Engine of a hybrid runs more often just to supply heat
- Climate system message, usually without check engine light
- Likely causes
- LikelyPower switch inside the heater shorted or failed
- PossibleInternal temperature or current measurement faulty
- RareCoolant or moisture inside the electronics housing
- RareSoftware fault in heater or commanding module, update available
- Repair
- Hard · Usually a job for a workshop.Typical cost: €400 – €2,000
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.