OBD-II code · Powertrain (generic)
P0C40 DC/DC Converter Temperature Sensor B High
The ECM detects a high fault on the dc/dc converter temperature sensor b. Reading cannot be used reliably for control.
Is it safe to drive with P0C40?
The car may go into limp mode (reduced power). Get it diagnosed before a long trip.
Common causes
- Most likelySignal wire shorted to B+
- PossibleOpen sensor
Repair at a glance
- Difficulty
- Easy
- DIY friendly
- Best left to a mechanic
- Typical labour
- 0.5–3 h
- Emissions test
- Usually unaffected
- Parts involved
- Dcdc Converter Temp Sensor B, Wiring Harness, Dcdc Converter
Related codes
- P0C3BDC/DC Converter Temperature Sensor A High
- P0C3DDC/DC Converter Temperature Sensor B Circuit
- P0C3EDC/DC Converter Temperature Sensor B Range/Performance
- P0C3FDC/DC Converter Temperature Sensor B Low
- P0C41DC/DC Converter Temperature Sensor B Intermittent/Erratic
- P0C42Hybrid/EV Battery Pack Coolant Temperature Sensor A Circuit
- P0C43Hybrid/EV Battery Pack Coolant Temperature Sensor A Circuit Range/Performance
Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.