P0C3CDC/DC Converter Temperature Sensor A Intermittent/Erratic
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- Can trigger limp mode
- Needs a drive cycle to confirm a fix
- How the car detects it
- P0C3C covers a signal from DC/DC converter temperature sensor A that drops out or jumps for short moments while staying mostly within range. The heat sink of a converter warms and cools slowly, so fast jumps point to the signal path rather than to real temperature changes. No manufacturer documents P0C3C publicly. The method is known from GM's hybrid tables for comparable thermistors, such as P0C37 for battery sensor F: the controller adds up signal changes in short windows and fails the test when several windows exceed a limit. CARB requires such inputs to be monitored for faults. Typical causes are a loose terminal, vibration damage or moisture at the converter connector. Unlike P0C3A and P0C3B, the fault may vanish between tests, so a wiggle test helps.
- What you may notice
- Intermittent hybrid or EV warning
- Occasional 12 V charging interruptions
- Likely causes
- LikelyLoose terminal or moisture at the converter connector
- PossibleHarness damaged by vibration with intermittent contact
- RareIntermittent fault inside the converter
- 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: €80 – €2,500
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.