Powertrain, generic · Transmission

P086F Neutral Position Sensor A Not Learned

Check engine lightUsually off
EmissionsNot relevant
Drive cycleNot required
Limp modeNo

Neutral position sensor A is a three-wire Hall sensor on the shift shaft of a manual gearbox that reports neutral to the engine module; start-stop may only switch the engine off in neutral. Audi uses it as sender G701 on the Q3 and A3, GM on the 2019 Corvette ZR1 manual, where its faults suspend the gear ratio checks. Thresholds and MIL status are not published. Analog neutral sensors need a learned neutral window to cover part and fitting tolerances. P086F means no valid value is stored, typically after a sensor, gearbox, clutch or module replacement, a software update or an aborted learn run; Schaeffler's patent rejects runs with an unsteady lever. FCA describes cruise control failing after service until the neutral learn is done, without new parts.

Likely causes

Learn procedure not done after replacing sensor, gearbox or module
Learn run aborted: lever strained, linkage misadjusted
Software update deleted learned values
Sensor fitted outside the learnable range or faulty

Symptoms

  • Start-stop not working
  • Cruise control cannot be set (FCA)
  • Fault appears after a workshop visit

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 sensorsensor wiringengine control modulemanual transmission

Related codes

P086AP086BP086CP086DP08B3P080A

References: gsi.ext.gm.com, patents.google.com, static.nhtsa.gov.