How severe is the code?
In terms of severity, a P0858 diagnostic code ranks extremely high. The presence of this engine error code can lead to the failure of the traction control system’s operation, which can seriously affect your vehicle’s safety.
Symptoms
Symptoms of a P0858 include:
- The traction control system has stopped functioning
- Delayed, harsh, or erratic shifting
- Limp mode
Causes
- Damaged wiring or corroded connectors
- Faulty traction control switch
- Faulty brake electronic control module / ABS module
- Faulty traction control module
How to diagnose the code?
The first thing to consider when diagnosing a P0858 OBDII fault code is the condition of the wiring and connectors. If there is an on/off switch for the anti-skid system, it should be inspected for signs of water damage and corroded or broken connectors. If there is an issue, the anti-skid module and possibly the ABS module will need to be tested.