What it means
The gear shift position circuit B reports a circuit high fault. Gear shift position feedback is unreliable on this channel.
At a glance
- Usually lights the check-engine light
- The engine or gearbox may go into limp mode
How it works
The transmission control module uses gear shift position feedback to confirm where the selector or shift mechanism is positioned. This code sets when position circuit B reads higher than the module expects, making that channel’s position feedback unreliable.
Common causes
Most likely first.
- Position sensor failed
- Wiring fault
- Connector pins corroded - high contact resistance
Symptoms
- Check engine or transmission warning light on
- Harsh, delayed, or missing shifts
- Possible limp mode (locked in one gear)
- Slipping or shuddering during gear changes
How to diagnose it
- Record freeze-frame data and compare live position circuit B readings with the reported gear while moving the selector, since this shows when the feedback becomes implausible.
- Inspect the position sensor and its connector for corrosion, loose or pushed-back pins, and damaged wiring that could affect circuit B.
- With the system safe to test, monitor circuit B while gently moving the harness to see whether the reading changes or the fault returns.
- Check circuit B continuity and for shorts to power or ground using the vehicle wiring diagram and the manufacturer's test procedure.
- If wiring and connections pass, test the gear shift position sensor and module input against the manufacturer's specification.
Common fixes
- Clean and secure corroded or loose position-sensor connector pins.
- Repair damaged wiring or a poor connection in gear shift position circuit B.
- Replace the faulty gear shift position sensor if its output is outside specification.
- Repair the transmission control module circuit only if testing confirms a module fault.
Can I keep driving?
Because the transmission may shift harshly, miss shifts, or enter limp mode, avoid long trips and heavy traffic; stop if the vehicle slips or loses drive. Continued driving with unreliable position feedback can make gear selection unpredictable.
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.