Powertrain, generic · Transmission

P08B3 Neutral Position Sensor B Not Learned

Check engine lightUsually off
EmissionsNot relevant
Drive cycleNot required
Limp modeNo

Analog neutral sensors report a position value, and the control module must learn which value means neutral to cover part and fitting tolerances. P08B3 says no valid learned value exists for sensor B, typically after replacing the sensor, gearbox or module, after a software update, or after an aborted learn. No manufacturer documents P08B3 publicly; the A counterpart P086F is used by GM on the LT5 Corvette. A Schaeffler patent describes the learn: the driver engages neutral and the gears, and a run is rejected if the reading wanders too much in its roughly one-second window. FCA notes a neutral sensor learn procedure after service that restores cruise control. CARB 1968.2 (e)(15) applies. Fix is usually a relearn by scan tool.

Likely causes

Learn procedure not done after sensor, gearbox or module replacement
Learn run aborted, lever unsteady or linkage misadjusted
Learned values erased by software update or module reset
Sensor mounted outside the learnable range or faulty

Symptoms

  • Start-stop unavailable
  • Cruise control may be inoperative
  • Appears right after a repair or software update

Repair estimate

DifficultyEasyWorkshop job
Parts and labour€30–150
Time0.2–1 h

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

Parts involved

neutral position sensor bengine control module

Related codes

P086FP08B2P08ADP08AE

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