What P2831 means
The TCM cannot read a valid position signal from shift fork A position sensor.
How the engine computer detects it
Selector engagement state is unknown.
Written from public technical sources and not yet checked by a mechanic. How we write these pages
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
Common causes
- Position sensor failed Most likely
- Wiring or connector fault Possible
How to diagnose P2831
- Read every stored code with an OBD-II scanner. If misfire or fuel trim codes are there too, fix those first: they often cause this one.
- Inspect the parts involved: shift fork a, shift fork position sensor a, wiring harness.
- Work through the causes above from most to least likely, cheapest checks first.
- Clear the code and drive a full drive cycle to confirm the repair held.
Vehicles that report P2831 most
| Vehicle | Years | Reports | Share | Median miles |
|---|---|---|---|---|
| Ford Focus | 2012–2013 | 8 | 57k |
Counts of owner complaints to the NHTSA that mention P2831 (8 in total), not failure rates: popular models get more complaints simply because more of them are on the road. Models with fewer than 3 complaints are left out.
Reading the code
- P
- Powertrain
- 2
- Generic (SAE) code
- 831
- Specific fault
Questions drivers ask
Can I drive with code P2831?
If the car shifts normally, drive gently to a shop. If it's stuck in one gear, slips, shifts harshly or won't move out of Park, don't drive it: have it towed.
Often reported together
Codes that owners mention in the same NHTSA complaints as P2831. They can point to a shared cause, so it's worth checking them together.
This page is general information, not a substitute for a professional diagnosis. Repair costs are rough estimates for parts and labor and vary by vehicle and region.