P2846Shift Fork B Position Sensor Incorrect Neutral Position Indicated
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- Can trigger limp mode
- How the car detects it
- P2846 flags a mismatch between the neutral reading of the fork B position sensor and the gear state the transmission module expects. Either the sensor claims fork B rests in neutral while the shaft speeds prove its gear carries load, or it reports an engaged fork where the module has commanded neutral. No manufacturer publicly documents P2846. CARB 13 CCR 1968.2 requires transmission inputs to be checked for rationality, and GM's 2023 Corvette dual-clutch table shows one way to do it: an unloaded rod has to read within a tolerance band around the learned neutral or engaged point. GM books such deviations for its second rod under P2837, though. Likely triggers are lost learned positions, a loosened sensor target or a worn detent; a relearn comes first.
- What you may notice
- Gears served by fork B refused or skipped
- Transmission warning with reduced performance
- Gear indicator disagrees with the actual gear
- Likely causes
- LikelyLearned neutral position of fork B missing after repair or module replacement
- PossibleMagnet or target on the fork B rod loosened or shifted
- RareWorn detent letting fork B settle off its neutral point
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Hard · Usually a job for a workshop.Typical cost: €80 – €2,500
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.