P0CA2DC/DC Converter Step Down Voltage 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
- P0CA2 means the step-down function of the DC/DC converter, which brings high-voltage battery power down to the 12 V network, is not working correctly. GM's 2013 eAssist table 13OBDG05C uses it for a shoot-through fault inside the 14 volt power module: if the module detects a failed silicon power switch, a single 25 ms detection at 9 to 32 V sets the code as Type A, so the MIL lights on the first trip. Documents GM supplied to NHTSA in recall query RQ13-003 on the 2013 Malibu mild hybrid show P0CA2 in dealer cases together with P0562 for low system voltage, power pack replacements, and engineering reviews of returned parts with no fault found. P0CA3 is the step-up counterpart. Without the converter the 12 V battery drains.
- What you may notice
- Check-engine lamp on the first trip, often with a charging warning
- Falling 12 V voltage, low-voltage codes such as P0562
- Hybrid assistance or auto-stop unavailable
- Likely causes
- LikelyFailed power semiconductor in the converter's step-down stage
- PossibleInternal fault of the power module or power pack assembly
- RareSpurious detection without a hardware fault, for example after supply dips
- 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: €300 – €3,000
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.