P2DFCHybrid/EV Battery Coolant Leak Detected
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- Can trigger limp mode
- Needs a drive cycle to confirm a fix
- How the car detects it
- P2DFC states that the liquid loop cooling the high-voltage battery is losing coolant. No manufacturer documents this exact code publicly. A GM patent explains how such a verdict is reached: a float or reed switch in the reservoir at the highest point of the loop is sampled in windows of a few seconds, only while the car stands level, the pump turns fast enough to purge air and pack temperature is in range; a low reading in two of the last three drive cycles counts as a leak, stores a code and lights the MIL. GM's Chevrolet Volt applies this under its own code P1FFE: sensor voltage of 1.38 to 2.84 V in 16 of 20 samples at standstill, seen twice within three key cycles, Type A. Since leaking coolant can reach the cells, charging or propulsion may be blocked. Sensor wiring faults are P2BE0 to P2BE3.
- What you may notice
- Hybrid or EV system service message and MIL
- Charging blocked or drive power reduced
- Coolant level in the battery reservoir visibly low, possibly traces of coolant under the car
- Likely causes
- LikelyLeaking hose, clamp or quick connector in the battery coolant loop
- PossibleLeak at the battery chiller, heat exchanger or cooling plates inside the pack
- PossibleCracked reservoir or leaking cap
- RareLoop not filled or bled correctly after a repair
- RareLevel sensor reporting low although the level is correct
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Workshop only · Usually a job for a workshop.Typical cost: €150 – €3,000
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.