Powertrain
Definition only
Lights the check engine lamp
P2840: Shift Fork D Position Circuit
Standardized SAE J2012 code · P28xx codes
What does P2840 mean?
The TCM cannot read a valid position signal from shift fork D position sensor. Selector engagement state is unknown.
The code tells you which monitor failed, not which part is broken. Test before replacing parts.
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
- High Position sensor failed
- Medium Wiring or connector fault
Likelihood is a general estimate across vehicles; your make and model may differ.
Add your car to see reports of P2840 on the same make and model first.
P2840 in the community
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