P0C3D: DC/DC Converter Temperature Sensor B Circuit
What to do
As P0C38 — and mention whether the 12-volt battery has been flat, because that is the symptom this fault actually produces.
What this code means
The second temperature sensor on the DC/DC converter has a circuit fault.
What the converter is, and why its faults present as a flat 12-volt battery, are at P0C38. A second sensor is coverage rather than redundancy — as with the inverter at P0BD1, the heat is not evenly spread and one sensor would either sit on the hot spot or miss it. Their disagreement is informative: one hot and one normal points at that part of the converter; both rising together points at cooling.
Likely causes
Start here
- Faulty DC-DC converter · specialist
- Corroded or loose connector · easy
Less common
- Low inverter coolant level · easy
- Air trapped in the inverter cooling circuit · moderate
Symptoms
Components involved
Information, not instruction
CarGeek is a reference, not a service manual. Its pages are written from public sources and from what other people have found, never from a manufacturer's own service information, so they can be wrong or incomplete for your particular vehicle. Some of what they describe carries real risk: high voltage, fuel under pressure, stored energy, hot and moving parts.
Have anything you intend to act on checked by a trained person against the manufacturer's own procedure for your vehicle. Nothing here replaces that procedure.
Community experience
Be the first to write this up
Nothing posted about this yet. Whatever you found is worth writing down — even a dead end saves someone the same afternoon.
What makes one worth reading:
- The car — make, model, year and engine. The same fault behaves differently on each.
- What you measured, not only what you replaced.
- What actually fixed it — or that nothing did, which is worth knowing too.
Sign in or create an account to add what you found about P0C3D.