P2C8AHybrid/EV Battery Interface Control Module A Performance
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- Can trigger limp mode
- How the car detects it
- Battery interface control modules are the satellite boards in the traction battery that measure cell voltages and temperatures and report them to the battery energy control module. P2C8A says module A is reachable but not working properly. GM uses the code on its Ultium EVs: preliminary information PIP6021 (Lyriq, Blazer EV, Equinox EV, later Optiq and Vistiq) blames a BECM calibration anomaly when P2C8A, P2C8B and U3577-U35AF are all set, with MIL or Service High Voltage and a draining 12 V battery; the fix is BECM programming and two manual resets. PIP6081 calls the same pattern a cell monitoring unit brownout on Hummer EV, Silverado EV and Escalade IQ. The earlier Volt checked comparable modules with its own code, a key value test, Type B.
- What you may notice
- MIL or Service High Voltage message
- 12 V battery discharging while parked
- Many battery communication codes stored at the same time
- Likely causes
- LikelyBattery energy control module software or calibration error
- PossibleSupply dip at the cell monitoring module (12 V battery weak, wake-up issue)
- RareDamaged communication or supply harness inside the battery pack
- RareFailed interface module A board
- 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: €100 – €5,000
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.