OBD-II code · Powertrain (generic, extended)
P2839 Shift Fork B Position Circuit High
Voltage on shift fork B position sensor signal line is above the expected window. Wire shorted to B+ or sensor open.
Is it safe to drive with P2839?
The car may go into limp mode (reduced power). Get it diagnosed before a long trip.
Common causes
- Most likelySignal wire shorted to B+
- PossibleOpen position sensor
- Less likelyConnector pins corroded - high contact resistance
Symptoms
- Check engine or transmission warning light on
- Harsh, delayed, or missing shifts
- Possible limp mode (locked in one gear)
- Slipping or shuddering during gear changes
Repair at a glance
- Difficulty
- Hard
- DIY friendly
- Best left to a mechanic
- Typical labour
- 3–10 h
- Emissions test
- Usually unaffected
- Parts involved
- Shift Fork B, Shift Fork Position Sensor B, Wiring Harness
Related codes
- P2834Shift Fork A Position Circuit High
- P283EShift Fork C Position Circuit High
- P2843Shift Fork D Position Circuit High
- P2866Shift Fork E Position Circuit High
- P2836Shift Fork B Position Circuit
- P2837Shift Fork B Position Circuit Range/Performance
- P2838Shift Fork B Position Circuit Low
- P283AShift Fork B Position Circuit Intermittent
- P283BShift Fork C Position Circuit
- P283CShift Fork C Position Circuit Range/Performance
Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.