The P0859: Traction Control Input Signal High refers to a condition where the traction control system is receiving a higher-than-expected voltage signal. This could be caused by a faulty sensor, wiring issues, or a malfunction in the traction control module or transmission control module (TCM). High voltage in the input signal can cause the traction control system to malfunction, leading to issues with vehicle stability and performance.
P0859 – Quick Overview
| Code | Information |
|---|---|
| Meaning | P0859: Traction Control Input Signal High |
| Is it serious? | Yes, it may cause traction control system malfunctions, affecting vehicle stability and safety. |
| Possible causes | – High voltage in the traction control input signal – Faulty sensor or wiring – Faulty traction control module or transmission control module (TCM) |
| How to diagnose? | – Test the signal for high voltage – Inspect wiring and connectors – Replace faulty components if needed |
P0859 Meaning
The P0859: Traction Control Input Signal High code indicates that the voltage in the traction control input signal circuit is above the specified range. This can lead to malfunctioning of the traction control system, which may reduce vehicle stability and cause performance issues, particularly on slippery or uneven surfaces.
Step-by-step diagnostic guide
| Action | Description | Tools Needed |
|---|---|---|
| Check for Other Codes | Use an OBD-II scanner to check for additional codes that may provide further insights into the traction control or transmission systems. | OBD-II Scanner |
| Inspect Traction Control System | Visually inspect the traction control module, sensor, and related components for signs of damage, wear, or misalignment. | Flashlight, Safety Gloves |
| Test the Signal for High Voltage | Use a multimeter to measure the voltage in the traction control input signal circuit and compare it with the manufacturer’s specifications. | Multimeter |
| Check Wiring and Connectors | Inspect the wiring and connectors for any damage, corrosion, or loose connections that could cause high voltage in the circuit. | Flashlight, Multimeter |
| Replace Faulty Components | If the sensor, wiring, or traction control module is found to be faulty, replace the necessary components to restore proper function. | Replacement Parts, Basic Tools |
| Clear the Code and Test Drive | After repairs, clear the code using an OBD-II scanner and test the vehicle to ensure proper traction control system operation. | OBD-II Scanner, Vehicle Owner’s Manual |
| Recheck for Codes | After the test drive, re-scan the system to confirm that the P0859 code does not return. | OBD-II Scanner |
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Hi, I am Juraj “Yuri” Lukacko. I got frustrated by unhelpful and scammy mechanics, so I decided to learn everything about car diagnostics myself. I test dozens of new car diagnostic tools every month along with learning new strategies to fix and customize cars. About Juraj Lukacko (Yuri)