What it means
The ECM detects a circuit fault on the dc/dc converter temperature sensor c circuit. Reading cannot be used reliably for control.
At a glance
- Usually lights the check-engine light
- The engine or gearbox may go into limp mode
How it works
The DC/DC converter reduces high-voltage battery power to the lower voltage used by vehicle electronics and the auxiliary battery. The ECM monitors temperature sensor C and sets this code when it detects a fault in that sensor’s electrical circuit, making its reading unreliable for converter control.
Common causes
Most likely first.
- Sensor failed
- Wiring or connector fault
Symptoms
- Hybrid/EV system warning light may turn on
- Reduced power or charging performance
How to diagnose it
- Use a scan tool to record freeze-frame data and compare sensor C with other converter temperature readings to see when the fault occurred.
- Inspect sensor C’s connector and nearby wiring for loose pins, corrosion, damage, or contact with hot or moving parts.
- Check the sensor circuit connections and continuity against the manufacturer’s specification.
- Test sensor C and its signal while monitoring live data to determine whether the fault follows the sensor or its wiring.
- After repairs, clear the code and confirm the reading remains plausible during converter operation.
Common fixes
- Reconnect and secure the temperature sensor C connector.
- Repair damaged wiring or poor circuit connections.
- Clean or repair corroded connector terminals.
- Replace temperature sensor C if it fails testing.
Can I keep driving?
Avoid relying on electric drive or charging if the vehicle shows reduced power or a hybrid/EV warning; the converter may not be protected using a reliable temperature reading. Follow the vehicle’s warning messages and stop if power drops sharply.
A code shows where the control module detected a fault, not always which part failed. Check the causes in order and confirm with a test before replacing parts. Have several codes? Check them together
This is a generic code: it means the same on every make. The car’s maker may add more detail in its own service information.