P0DAABattery Charging System Isolation Fault
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- How the car detects it
- P0DAA reports that the resistance between the charging-side HV bus and chassis ground has fallen too low, so the charging path or the battery is no longer safely insulated. GM documents the logic for the 2014 Chevrolet Volt and Cadillac ELR in the HPC2 (VICM): in charge-only mode the active isolation resistance is measured, at most once per wake-up; below 325 kOhm, or 400 kOhm while the code is active, for 10 s, and with five of the last ten results low, the code sets as Type A with MIL after one trip. GM preliminary information PIC5920 links it to vehicles that will not charge and points to coolant leaking into the battery pack or insulation loss in the cells; technicians check the pack drain plug and reprogram HPCM2 and BECM, and call support if isolation stays under 275 kOhm. GM used P0AA6 for this on 2011–13 Volts.
- What you may notice
- Vehicle will not charge
- MIL on (GM Type A)
- Low coolant level in the battery coolant reservoir
- Likely causes
- LikelyCoolant leaking into the battery pack (GM)
- PossibleInsulation loss within battery cells or sections (GM)
- PossibleOutdated HPCM2/BECM calibration (GM, 2011–2014)
- RareDamaged insulation in the on-board charger or charging cables
- Repair
- Workshop only · Usually a job for a workshop.Typical cost: €100 – €6,000
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.