Powertrain, generic · Transmission

P0908 Gate Select Position Circuit A Intermittent

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modePossible

Points to a gate select position signal on circuit A that drops out or jumps for short moments in an automated manual gearbox, too briefly or too irregularly for a steady low or high fault. Loose terminals, a damaged harness that moves with the engine, or moisture in the connector at the shift and select actuator are the usual reasons. No manufacturer documents this code publicly. An Aisin AI patent explains why even short sensor dropouts matter: if a stroke sensor fails while driving, the controller can no longer confirm the engaged gear and must switch to a fallback strategy. CARB requires circuit and rationality checks on such inputs. P0904 to P0907 are the steady faults of the same circuit. Drivers often notice occasional neutral drops or refused shifts that vanish again.

Likely causes

Loose or spread terminals at the sensor or actuator connector
Harness damage that only opens or shorts under engine movement
Moisture or corrosion in the connector near the gearbox

Symptoms

  • Warning light that comes and goes
  • Occasional drop to neutral or refused shift
  • Fault often disappears after restarting the engine

Repair estimate

DifficultyMediumWorkshop job
Parts and labour€50–1,200
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

P0904P0905P0906P0907P0909

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