Powertrain, generic · Transmission

P08AE Neutral Position Sensor B Circuit Range/Performance

Check engine lightUsually off
EmissionsNot relevant
Drive cycleNot required
Limp modeNo

Sensor B is the second neutral sensor or channel on the shift shaft of a manual gearbox, complementing sensor A (P086A ff). P08AE means its signal is electrically present but implausible: it stays outside the expected window, does not change when gears are engaged, or reports neutral while the gear ratio says otherwise. No manufacturer documents this code publicly; Audi's G701 and GM's LT5 Corvette are only known to use the A codes. Per a GM patent the neutral sensor is a Hall sensor pair with a PWM output that changes with every gear, so such a plausibility check is possible. CARB 1968.2 (e)(15) requires rationality monitoring of inputs. Start-stop is usually disabled; repair often means adjusting or replacing the sensor.

Likely causes

Sensor B or its magnet misaligned after gearbox work
Sensor B drifting or faulty
Worn shift shaft or detent giving an unclear neutral position

Symptoms

  • Start-stop unavailable
  • Start system or gear indicator message in the cluster
  • No noticeable change while driving

Repair estimate

DifficultyMediumWorkshop job
Parts and labour€60–400
Time0.5–2 h

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

Parts involved

neutral position sensor bwiring harnessengine control module

Related codes

P08ADP08AFP08B0P08B1P08B2P086B

References: law.cornell.edu, patents.google.com, patents.google.com, static.nhtsa.gov.