Powertrain, generic · Transmission

P091D Gear Shift Position Circuit B High

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modePossible

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.

Likely causes

Signal wire of circuit B shorted to supply or battery voltage
Open sensor ground
Faulty shift position sensor B

Symptoms

  • Transmission or engine warning light on
  • Restricted gear changes or a held gear
  • Engine start may be blocked if neutral cannot be confirmed

Repair estimate

DifficultyHardWorkshop job
Parts and labour€80–1,500
Time0.5–4 h

Typical range across vehicles; the real cost depends on what the testing finds.

Parts involved

gear shift position sensor bwiring harnesstcm

Related codes

P091AP091BP091CP0917P095D

References: law.cornell.edu, patents.google.com, patents.google.com.