What it means
The ECM detects a circuit fault on the 14 volt power module 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
Current Sensor B monitors current in the 14-volt power module, and the engine control module uses its signal to assess and control the low-voltage power system. This code sets when the Sensor B circuit has an electrical fault and its current reading cannot be relied on.
Common causes
Most likely first.
- Sensor failed
- Wiring or connector fault
Symptoms
- Check-engine or hybrid-system warning light on
- Charging-system warning light may come on
- Charging or 12-volt system performance may be affected
How to diagnose it
- Use a compatible scan tool to record freeze-frame data and check whether the Sensor B reading is missing, fixed, or implausible.
- Check for related charging-system or 12-volt system codes and note whether the charging warning appeared at the same time.
- With the vehicle switched off, inspect the Sensor B connector and accessible wiring for looseness, corrosion, damaged insulation, or bent pins.
- Using the vehicle wiring diagram, check the Sensor B circuit for opens, shorts, and poor connections according to the manufacturer's procedure.
- If the wiring and connector pass, test Current Sensor B using the specified procedure and replace it if it fails.
Common fixes
- Secure a loose Current Sensor B connector.
- Repair damaged wiring or corroded terminals in the Sensor B circuit.
- Replace Current Sensor B if circuit checks confirm the sensor has failed.
- Clear the code and confirm the Sensor B reading and charging-system operation.
Can I keep driving?
A faulty Sensor B signal can affect 12-volt charging control and may lead to warning lights or electrical problems. Limit driving if the charging warning is on, and stop safely if lights dim, electrical systems fail, or the vehicle reports a power-system fault.
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.