What it means
The DC/DC converter step-up (boost) voltage performance is outside calibration. Output voltage does not match commanded value.
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's step-up function raises voltage where the hybrid or EV system requires it. The control module compares commanded boost output with the measured result, and this code sets when the step-up output fails to follow the command within the vehicle's calibration.
Common causes
Most likely first.
- Regulator characteristic drifted
- Load mismatch
Symptoms
- Check-engine or hybrid-system warning light on
- Charging-system warning light may come on
- 12-volt electrical system performance may be affected
How to diagnose it
- Record freeze-frame data and note whether the mismatch occurred during acceleration, charging, or another change in hybrid-system demand.
- Use a scan tool to compare commanded and actual step-up output and review related hybrid-system status.
- Inspect accessible converter connectors and wiring for loose connections, corrosion, heat damage, or chafing, observing high-voltage precautions.
- Check for related battery, inverter, or DC/DC converter codes that could explain a load mismatch or affect the boost command.
- Test the step-up circuit and converter response using the vehicle's service procedure, comparing results with the manufacturer's specification.
Common fixes
- Secure or repair a loose, corroded, or damaged converter connection.
- Repair wiring faults affecting the step-up command or feedback circuit.
- Resolve a related battery or inverter fault if it is causing the boost mismatch.
- Replace the DC/DC converter if its step-up performance remains out of specification after circuit and load checks.
Can I keep driving?
Limit driving if the hybrid warning, charging warning, or reduced-power behavior is present because the converter may not provide the voltage the system needs. Stop safely if propulsion becomes unreliable, and follow the vehicle's high-voltage safety instructions.
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.