Powertrain, generic · Transmission

P0905 Gate Select Position Circuit A Range/Performance

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modePossible

Plausibility fault of the gate select position signal on circuit A in an automated manual gearbox. The signal is electrically within limits, but it does not fit what the control module expects: typical checks compare the measured select travel with the learned gate positions and the commanded target gate. No manufacturer documents this code in freely citable material. Patents by Aisin AI on select control with target and actual gate, and on fallback strategies after a stroke sensor failure, show how the module depends on this signal; CARB requires rationality checks on such inputs. P0904, P0906 and P0907 cover the electrical faults, P0909 a select movement that misses its target. The driver typically sees a fallback mode with no or limited shifting.

Likely causes

Worn or drifting gate select sensor, main and redundant tracks disagree
High resistance at connector pins distorting the sensor voltage
Gate positions not relearned after actuator, clutch or TCM replacement
Loose or displaced magnet or sensor mounting on the select shaft

Symptoms

  • Check engine or transmission warning light on
  • Gearbox drops to neutral or refuses certain gears
  • Slow or jerky gear changes in fallback mode

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

gate select position sensor awiring harnesstcm

Related codes

P0904P0906P0907P0908P0909P09A3

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