What it means
The ECM detects a circuit fault on the dc/dc converter current sensor b 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
DC/DC converter current sensor B measures converter current so the control module can manage charging and electric drive. This code sets when the current sensor B circuit is faulty and its reading cannot be trusted, which can lead to limited charging, reduced electric drive, or reduced range.
Common causes
Most likely first.
- Sensor failed
- Wiring or connector fault
Symptoms
- Hybrid or EV system warning light
- Reduced power or limited electric drive
- Charging may be limited
- Reduced electric range
How to diagnose it
- Review freeze-frame data and current sensor B live readings alongside charging status to determine when the circuit becomes unreliable.
- Inspect the DC/DC converter current sensor B connector and harness for looseness, corrosion, chafing, or damage.
- Check the sensor B circuit connections and wiring against the vehicle wiring information, including its power, ground, and signal paths where applicable.
- Compare current sensor B output with the manufacturer's specification during converter operation.
- If the wiring and connector are sound, test the current sensor B and DC/DC converter to isolate the fault.
Common fixes
- Secure the current sensor B connector and correct poor terminal contact.
- Repair damaged wiring in the DC/DC converter current sensor B circuit.
- Replace current sensor B if it fails the manufacturer's tests.
- Repair the DC/DC converter if it is causing the sensor B circuit fault.
Can I keep driving?
Reduced charging or electric drive can affect available power and range, so keep trips short if those symptoms appear. If the vehicle limits power or displays a shutdown warning, stop safely and arrange assistance.
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.