KlaroFault codeP0858
MODERATETraction Control Input Signal Low
What this code means
Traction Control Input Signal Low.
P0858 is a generic code: it means the same thing on every make. P0858 belongs to family P08xx — Transmission (continued). Its page explains how to read a code and groups all its codes by part.
Type of fault
The control unit reads a voltage on this circuit below its expected range. Usual causes: a wire shorted to ground or broken, a corroded or loose connector, or the component itself. Check the wiring and connector before replacing the part — that is where many of these faults turn out to be.
Traction control signal
The traction control unit, part of the ABS/ESP system, asks the engine control unit to cut torque when a wheel slips. These codes concern the signal between the two.
What you notice
Traction control or ESP warnings, power that drops unexpectedly or a system that does not intervene.
How to check it
Read the codes of the ABS/ESP unit too: the source of the fault is often there, such as a wheel speed sensor. Then check the communication wiring between the modules.
What to do
Have it checked this week. The car remains usable, but the fault will not clear itself and will fail the roadworthiness test.
Clearing a code switches the light off but repairs nothing: if the fault remains, the code comes back. Clearing a fault code yourself →
How to read this code
- PPowertrain
- 0standardised code
- 8Transmission (continued)
- 58P0858
