P091D code meaning
Gear Shift Position Circuit B High
Powertrain system Generic code P09xx codes Check engine light
What P091D means
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.
P091D at a glance
- Check engine lightYes, usually on
- Emissions testCan fail
- Limp modePossible
- Repair difficultyHard
- Typical labor0.5 to 4 hours
- Clears after repairWhen cleared with a scanner
Symptoms of P091D
- Transmission or engine warning light on
- Restricted gear changes or a held gear
- Engine start may be blocked if neutral cannot be confirmed
Common causes of P091D
- Most likelySignal wire of circuit B shorted to supply or battery voltage
- PossibleOpen sensor ground
- PossibleFaulty shift position sensor B
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Gear shift position sensor bWiring harnessTCM
What each part of P091D means
| P | Powertrain system: engine, fuel system, ignition, emissions and transmission. |
| 0 | Generic code: it means the same on every make (SAE standard). |
| 9 | Area: transmission. |
| 1D | The exact fault in that area. |
What to do next
- Note P091D and any other codes stored with it: several codes together often point to one cause.
- Check for loose connectors and damaged wiring around the parts the code names.
- Check open recalls for your car: some faults are fixed for free by the dealer. Enter your VIN.
- Clear the code only after the repair. If it comes back, the fault is still there.
Buying a used car? Scan it for stored codes before you pay. A recently cleared memory can hide a problem.
Questions about P091D
What does P091D mean?
P091D means "Gear Shift Position Circuit B High". 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. It is a generic code, so it means the same on every make.
Is it safe to drive with P091D?
Drive gently and only to a workshop. With P091D the car can go into limp mode (reduced power) to protect itself.
Will P091D fail an emissions test?
Yes, it can. P091D is emissions-related, so most inspection programs fail a car while it is stored or while the check engine light is on.
How hard is P091D to fix?
Difficulty: hard. A typical repair takes 0.5 to 4 hours of work. This is a job for a workshop.
Will P091D clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.