What it means
The ECM detects a intermittent/erratic 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 for the vehicle’s low-voltage electrical system. The ECM monitors temperature sensor C and sets this code when its signal changes unpredictably or drops out intermittently, often because of a loose connector, unstable ground reference, or vibration-sensitive contact.
Common causes
Most likely first.
- Sensor connector not seated
- Noisy ground reference
- Connector with intermittent contact under vibration
Symptoms
- Hybrid or EV system warning light
- Intermittent reduced power
- Charging may be interrupted
- Reduced electric range
How to diagnose it
- Save freeze-frame data and review sensor C’s live-data history, if available, for sudden jumps or dropouts.
- Inspect the sensor C connector for incomplete seating, damaged seals, corrosion, or pins that move in the connector body.
- Check the sensor ground and wiring for damage, poor connections, or contact with vibrating or moving parts.
- With live data monitored, gently move the accessible sensor C harness and connector to see whether the reading changes.
- Test the sensor and circuit connections against the manufacturer’s specification, then verify stable readings after repair.
Common fixes
- Seat and secure the sensor C connector.
- Repair loose, corroded, or damaged terminals and wiring.
- Restore a stable ground reference for the sensor circuit.
- Replace sensor C if it produces intermittent readings despite sound wiring and connections.
Can I keep driving?
Intermittent power loss or charging interruption can return without warning, so avoid long trips and demanding loads while the fault persists. Stop safely if power becomes limited or the vehicle displays a stop-driving warning.
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.