OBD-II code · Powertrain (generic)
P0859 Traction Control Input Signal High
The traction control input signal to the ECM reports a input signal high condition. Engine torque reduction during wheel slip cannot be commanded reliably.
Is it safe to drive with P0859?
The car may go into limp mode (reduced power). Get it diagnosed before a long trip.
Common causes
- Most likelySignal wire shorted to B+
- PossibleTCS module output high
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
- Medium
- DIY friendly
- Best left to a mechanic
- Typical labour
- 0.5–3 h
- Emissions test
- Usually unaffected
- Parts involved
- Traction Control Module, Wiring Harness, Ecm
Related codes
Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.