What it means
The redundant park pawl position sensor B reads 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 park pawl position sensor uses two position signals so the transmission module can check that the mechanical lock is engaged or released as expected. P271D sets when the B signal rises above its allowed range, which can make the module uncertain whether the vehicle is securely in Park.
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 or transmission warning light on
- Park engagement or release may be unreliable
- Transmission may not shift out of Park
How to diagnose it
- Check freeze-frame data and live park-pawl position readings to see whether sensor B stays high or changes when Park is selected and released.
- Inspect the sensor B connector and nearby harness for moisture, corrosion, backed-out pins, or chafing that could interrupt the signal.
- With the code active, gently move the harness while watching sensor B data to check for a change that points to an intermittent connection.
- Using the vehicle's wiring diagram, check the sensor B signal for a short to the 5 V reference and inspect the reference and ground circuits.
- Test the sensor element and circuit continuity against the manufacturer's specification before replacing the sensor or considering a module fault.
Common fixes
- Clean and reseat the sensor B connector; repair loose or corroded terminals.
- Repair chafed or damaged sensor B wiring, including any short to the 5 V reference.
- Replace the park pawl position sensor if its B element is open or fails testing.
- Repair the park pawl mechanism or its control system if sensor readings remain incorrect after circuit repairs.
Can I keep driving?
If Park engagement or release is unreliable, do not rely on the transmission to hold the vehicle; use the parking brake and avoid driving until the fault is checked. The vehicle may fail to shift out of Park or may not be securely locked when parked.
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.