P0C3ADC/DC Converter Temperature Sensor A Low
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- Can trigger limp mode
- How the car detects it
- P0C3A means the signal of DC/DC converter temperature sensor A is below its valid range. Low refers to the signal voltage: with an NTC thermistor and pull-up, as GM uses for its hybrid temperature sensors, a short to ground or a failed element reads as extreme heat. No manufacturer documents P0C3A publicly. Mercedes-Benz shows the opposite case for the same sensor, P0C3B as a short to positive, on the EQB and the G-Class, and Ram the plausibility code P0C39. CARB requires the converter's inputs to be checked for out-of-range values. Because the controller must assume an overheated power stage, it limits or stops the converter output; the 12 V battery then supplies the car alone and a low-voltage warning may follow. The sensor is usually built into the converter.
- What you may notice
- Hybrid or EV system warning
- 12 V battery warning, system voltage dropping
- Reduced power or restricted functions
- Likely causes
- LikelySensor A signal shorted to ground inside the converter or its harness
- PossibleShorted temperature element A, usually requiring converter replacement
- RareConverter really overheated due to a cooling fault
- 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 – €2,500
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.