Powertrain, generic · Transmission

P08B0 Neutral Position Sensor B Circuit High

Check engine lightUsually off
EmissionsNot relevant
Drive cycleNot required
Limp modeNo

P08B0 reports that the signal of neutral position sensor B on a manual gearbox is above its upper electrical limit. With a three-wire Hall sensor this usually points to an open signal or ground wire or a short to voltage. No manufacturer documents P08B0 publicly. For the A sensor Audi does: the 2019–20 Q3 and 2022–23 A3 store P086D/P086E because the wires to sender G701 were too short and were pulled apart by shifting, fixed by lengthening them 20 mm; the same harness logic applies to a B sensor. A GM patent explains the dual-Hall neutral sensor with PWM output. CARB 1968.2 (e)(15) requires circuit monitoring. Low is P08AF; start-stop is typically off.

Likely causes

Signal or ground wire pulled apart, harness too short
Signal wire shorted to voltage
Sensor B open internally

Symptoms

  • Start-stop does not switch the engine off
  • Start system warning in the cluster
  • Fault may come and go with gear changes

Repair estimate

DifficultyMediumWorkshop job
Parts and labour€50–350
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

P08ADP08AEP08AFP08B1P086D

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