P091DGear Shift Position Circuit B High
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- Can trigger limp mode
- How the car detects it
- Set when the shift position signal on circuit B of an automated manual gearbox stays above its highest valid value for longer than a calibrated time. The signal line may be shorted to sensor supply or battery voltage, the sensor ground may be open, or the sensor may be faulty. No manufacturer documents this code publicly. Patents from Aisin AI and Nissan/Aichi present the shift stroke or shift position sensor as the feedback for gear engagement, so a reading above the valid band leaves the module unable to judge this channel. CARB requires out-of-range checks on such inputs. P091C is the opposite low fault, P0917 and P095D are the high faults of circuits A and C, P091B the plausibility fault of circuit B. Shifting is usually restricted.
- What you may notice
- Transmission or engine warning light on
- Restricted gear changes or a held gear
- Engine start may be blocked if neutral cannot be confirmed
- Likely causes
- LikelySignal wire of circuit B shorted to supply or battery voltage
- PossibleOpen sensor ground
- PossibleFaulty shift position sensor B
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Hard · Usually a job for a workshop.Typical cost: €80 – €1,500
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.