P0858 OBD-II Trouble Code: Traction Control Input Signal Low

Our certified mechanics come to you · 12-month, 12,000-mile warranty

SCHEDULE P0858 DIAGNOSTIC Get a fair and transparent estimate upfront
Red-stars EXCELLENT RATING ON

Cost of diagnosing the P0858 code

P0858 is a diagnostic trouble code (DTC) for "Traction Control Input Signal Low". This can happen for multiple reasons and a mechanic needs to diagnose the specific cause for this code to be triggered in your situation. Our certified mobile mechanics can come to your home or office to perform the Check Engine Light diagnostic for $70.00. Once we are able to diagnose the problem, you will be provided with an upfront quote for the recommended fix and receive $30.00 off as a credit towards the repair. All our repairs are backed by our 12-month / 12,000-mile warranty.

Cars Estimate Credit towards follow-up repair Earliest Availability
Ford$70.00$30.00
Toyota$70.00$30.00
BMW$70.00$30.00
SCHEDULE P0858 DIAGNOSTIC Get a fair and transparent estimate upfront

diagnostic check engine light

P0858 code definition

When the powertrain control module (PCM) detects a problem with the traction control input signal circuit, a P0858 trouble code is stored. The traction control input signal circuit delivers data to the PCM via a signal, which the PCM then uses to calculate how much the engine revolutions per minute (RPMs) are needed, engine timing, and how much fuel is needed for current vehicle traction. The P0858 trouble code only applies to vehicles that have an electronic traction control system. Some related trouble codes include P0856, P0857, P0859, and P0860.

What the P0858 code means

When the PCM, or a related module, doesn't receive input from the traction control module, a P0858 trouble code is stored and the check engine light illuminates. In some models, the traction control light might also illuminate and the transmission will be placed in Limp-in mode.

What causes the P0858 code?

A defective traction control ON/OFF switch is the most likely culprit behind the storage of a P0858 trouble code. Other causes can include damaged wiring or electrical connectors, corrosion in the sensor connector, and liquids spilled into the traction control switch.

What are the symptoms of the P0858 code?

Symptoms of a P0858 trouble code include the traction control system failing to operate, which is most obvious in slippery driving conditions. In addition to the warning lights, drivers can encounter problems when shifting gears and an increase in overall fuel usage while driving.

How does a mechanic diagnose the P0858 code?

To properly diagnose a P0858 trouble code, a mechanic needs an advanced scanner, digital volt/ohmmeter, a specialized scanner for testing the Controller Area Network (CAN) Bus harness, and a CAN Bus system wiring diagram. In addition, the mechanic should perform the following when diagnosing:

  • Inspect the wiring, connectors, and components. In particular, look for faulty, corroded, or damaged items during inspection.
  • Download any stored trouble codes or freeze frame data.
  • Install a memory-saving device and test the pins of the CAN Bus harness for wiring for fault using a specialized CAN Bus scanner. The mechanic should keep in mind that this process is time consuming and cost prohibitive.
  • Using a digital volt/ohmmeter, check the CAN Bus circuits, control modules, connectors, and fuses for fault.
  • When checking these components, connectors, and wiring, make sure to test for reference voltage and continuity with the battery ground.
  • Using the volt/ohmmeter, check the continuity and ground at the traction control ON/OFF switch.
  • Clear and retest the system to see if the problem returns.

Common mistakes when diagnosing the P0858 code

Mechanics most commonly cite the traction control module as being at fault, when in fact the problem lies with a faulty switch, circuit, or connector. Subsequent replacement of the traction control module does not fix the problem causing the P0858 trouble code and the code returns.

How serious is the P0858 code?

While a P0858 trouble code usually doesn't affect the operation of a vehicle with the code, it can lead to issues with gaining proper traction in slippery conditions. In addition, transmission issues in the form of shifting problems are commonly experienced with this code, as well as a decrease in the overall fuel efficiency of the vehicle.

What repairs can fix the P0858 code?

Fixing a P0858 trouble code requires the mechanic to complete the following repairs:

Need help with a P0858 code?

YourMechanic offers certified mobile mechanics who will come to your home or office to diagnose and repair your vehicle. Get a quote and book an appointment online or speak to a service advisor at 1-800-701-6230.

trouble codes
P0858
OBD-II

Fast and easy Check Engine Light is on Inspection service at your home or office.

SCHEDULE P0858 DIAGNOSTIC
Get a fair and transparent estimate upfront

Recent Check Engine Light is on Inspection reviews

Excellent Rating


YourMechanic Check Engine Light is on Inspection Service

Average Rating

4.5/5

Number of Reviews

3,484

Rating Summary
3,176
153
40
23
92
3,176
153
40
23
92

Richard

10 years of experience
415 reviews
Richard
10 years of experience
This is the second time I’ve had Richard work on my car. He always does an outstanding job and is quick, knowledgeable and professional. Highly recommended!!
2012 DODGE CHALLENGER - CHECK ENGINE LIGHT IS ON - LAS VEGAS, NEVADA

Michael

13 years of experience
372 reviews
Michael
13 years of experience
Mike was an absolute professional when he arrived. He walked me thru the whole process of my repairs and also made good recommendations for preventive issues. His mechanical knowledge and good customer services was a breath of air and greatly appreciated :-)
2007 CHEVROLET AVALANCHE - CHECK ENGINE LIGHT IS ON INSPECTION - MARIETTA, GEORGIA

Rodrigo

10 years of experience
85 reviews
Rodrigo
10 years of experience
Rodrigo was exactly on time, very professional and friendly. He assessed my car, let me know the exact problem when a previous mechanic from a shop in my area was unable to. I felt he was very honest and sincere letting me know the level of urgency that I deal with the issue. Absolutely no pressure. I will absolutely use Rodrigo the next time I need anything to do with my car and will tell everyone about him. This is such a great service, I will never go to another mechanic again. It is so convenient. I couldn’t be happier. :)
2013 SMART FORTWO - CHECK ENGINE LIGHT IS ON - LAS VEGAS, NEVADA

Ricardo

8 years of experience
223 reviews
Ricardo
8 years of experience
Great service and was very helpful on what maintenance my vehicle needed and what to expect in the future. Would definitely recommend to anyone and will.
2004 MITSUBISHI LANCER - CHECK ENGINE LIGHT IS ON - LOS ANGELES, CALIFORNIA

More related articles

P2422 OBD-II Trouble Code: Evaporative Emissions Control System (EVAP) Vent Valve Stuck Closed
Diagnostic Trouble Code (DTC): P2422 P2422 code definition Evaporative Emissions Control System (EVAP)...
What are the Car Pool Rules in Hawaii?
Hawaii is widely regarded as a land of vacation and relaxation, and as such, its scenic roads and routes are far better known than the state’s freeways. But, as with all...
Auto Safety Tips
Driving is more than a way to get from point A to point B. Owning and driving a car can also be a highly enjoyable experience. Whether a person is driving...

Related questions

Q: The truck cut out suddenly

Code P0722 is an output shaft sensor code for the transmission. While that may be an indication of an issue, it would not cause the truck to just quit. A catastrophic failure of the fuel pump, ignition system, or engine...

Q: Where is the plug in for the code reader? 2013 Honda Civic

I am working on this

Q: Getting error codes P0599 and P0171. Ive cleaned the O2 sensors but have no idea where to go from here.

Hello. Code P0599 is the code for an issue with the thermostat heater control circuit, while P0171 is for a lean condition on bank 1. P0599 is set when the computer detects that there is an issue with the electronically...

How can we help?

Our service team is available 7 days a week, Monday - Friday from 6 AM to 5 PM PST, Saturday - Sunday 7 AM - 4 PM PST.

1-800-701-6230 · hi@yourmechanic.com