What it means
The position sensor signal for actuator B on bank 1 is above the upper diagnostic threshold. Wiring faults of this kind typically come from chafing, water ingress at connector seals, or pin push-back — a wiggle test on the harness while the code is active often confirms the location.
At a glance
- Usually lights the check-engine light
How it works
The B rocker arm actuator position sensor reports switching position on bank 1. This high-circuit code sets when the signal exceeds its upper diagnostic threshold, which can happen if the signal wire is open or shorted to the sensor's 5 V reference.
Common causes
Most likely first.
- Open sensor element
- Signal wire shorted to the 5 V reference
- Connector pins corroded - high contact resistance
Symptoms
- Check-engine light
- Reduced engine power or acceleration
- Rough running or engine misfire
How to diagnose it
- Record freeze-frame data and review live B position-sensor data on bank 1 to confirm the signal is high when the fault occurs.
- Inspect the sensor connector and bank 1 harness for loose or corroded pins, damage, or contact with the 5 V reference wire.
- Gently move the harness while watching the live signal to check for an intermittent open or short.
- Test the signal wire for an open and for a short to the 5 V reference using the manufacturer's procedure.
- If wiring is sound, test the B sensor output and module input against the manufacturer's specification.
Common fixes
- Reconnect or clean a loose or corroded bank 1 B sensor connector.
- Repair an open signal wire or a short to the 5 V reference.
- Replace the B position sensor if its element is open.
- Repair the module-side connection if testing identifies it as the cause.
Can I keep driving?
Avoid hard acceleration and limit driving if the engine has reduced power or runs roughly, since the controller cannot reliably determine bank 1 actuator B's position. Stop if severe misfiring develops or the check-engine light flashes.
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.