P0C3DDC/DC Converter Temperature Sensor B Circuit
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- Can trigger limp mode
- How the car detects it
- P0C3D is the general circuit code for the second temperature sensor of the DC/DC converter, which turns high-voltage battery power into 12 V supply. Converters with two sensors watch separate parts of the power stage or cross-check one sensor against the other. No manufacturer documents P0C3D publicly. Sensor B itself appears in bulletins: Mercedes-Benz lists P0C4000, a short to positive of sensor B, on the EQB and the G-Class, and Ram the plausibility code P0C3E as temperature sensor 2 on the 2021 1500 eTorque. Sensor A uses P0C38 for the same fault class. CARB requires such converter inputs to be monitored. A circuit fault makes the controller limit or stop the converter, so the 12 V battery may run down and warnings follow.
- What you may notice
- Hybrid or EV system warning
- 12 V battery warning
- Likely causes
- LikelyConnector or wiring fault in the sensor B circuit
- PossibleFailed temperature element B inside the converter
- RareConverter or hybrid control software misjudging the sensor
- 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 – €2,500
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.