P0859 Traction control system input high
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P0859 – OBD-II Trouble Code Technical Description
High traction control input
What does the fault code mean P0859?
DTC P0859 indicates the traction control system input level is high. This means that there is a communication error between the engine control module (PCM) and the traction control module.
Traction control plays an important role in preventing wheel spin on slippery roads by working with the ABS system to effectively apply braking force to the spinning wheels. Code P0859 can cause the traction control system to disable and, in some cases, the stability control, cruise control and ABS braking functions to be disabled.
To resolve this issue, it is recommended that you conduct a thorough diagnosis of all components associated with this code, including wheel speed sensors, engine speed sensors, throttle position sensors, and other transmission sensors. Only once the specific cause has been identified can repairs be made, which may include replacing damaged sensors or wiring and repairing associated control modules.
Possible reasons
Code P0859 may indicate the following problems:
- Traction control switch malfunction.
- Problems with the wheel speed sensor or drive ring.
- Damaged, burnt, shorted or corroded wiring and connectors.
- Malfunctions in the ABS system.
- Potential PCM malfunction.
What are the symptoms of a fault code? P0859?
To diagnose code P0859, it is important to look for the following symptoms:
- Problems with traction on slippery surfaces.
- Abrupt or unsuccessful gear shifting.
- The Malfunction Indicator Light (MIL) or check engine light comes on.
- Disabling the traction control system.
- Inoperative stabilization system.
- Inability to activate cruise control.
- Disables the ABS brake function.
Although the P0859 code is not critical to driving the vehicle, it is recommended that it be repaired immediately to avoid possible malfunctions in the auxiliary systems.
How to diagnose a fault code P0859?
When diagnosing DTC P0859, the following steps are recommended:
- Check manufacturer's technical bulletins to identify known problems and solutions, which can save time and money in diagnosis.
- Test the traction control switch using a multimeter as it is often the root cause of the P0859 code.
- Inspect all wires and connectors associated with the system and ensure the integrity of the wheel speed sensor and drive ring.
- If the P0859 code remains after following the above steps, it is recommended that you contact a professional to diagnose and, if necessary, test the engine control module.
As for the incidence of the P0859 code problem, it may be higher on brands such as Ford. Additionally, sometimes this error may be accompanied by other trouble codes such as P0856, P0857, P0858.
Diagnostic errors
When diagnosing a P0859 code, some common errors may occur including:
- Incomplete or incorrect scanning of all system-related wires and connectors, which may result in missing key problem areas.
- Incorrect identification of the root cause of the error, which may result in replacing unnecessary components and not correcting the actual problem.
- Incorrect interpretation of data received from the code reader, which can lead to incorrect diagnosis and incorrect corrective action.
- Failure to sufficiently check all possible problem areas such as wheel speed sensors, drive rings, wires and connectors may result in an incomplete diagnosis and failure to resolve all issues associated with the P0859 code.
How serious is the fault code? P0859?
Trouble code P0859, although it can cause some problems with the vehicle's operation, is usually not critical to driving safety. However, it can disable some important systems such as traction control, stability control, cruise control and ABS braking function. Therefore, although the vehicle may continue to drive, it is recommended to correct this problem immediately to avoid possible consequences and maintain optimal vehicle performance.
What repair will help eliminate the code? P0859?
To resolve code P0859, the following is recommended:
- Check and, if necessary, replace the traction control switch if it is faulty.
- Check and repair the wiring and connectors associated with the traction control system to ensure their integrity.
- Check and, if necessary, replace the wheel speed sensors and associated drive rings.
- Check and, if necessary, replace the engine control module if other measures fail.
To effectively repair and resolve the P0859 code, it is important to conduct a thorough diagnosis and ensure that the root cause of the problem is accurately identified and corrected.
