Easy one-page printout for the garage or repair shop
This summary uses the existing diagnostic information shown in full below.
This code means that the car's computer is getting a signal from the traction control system that is too high. It's like when you turn up the volume too much on a radio, and it gets too loud.
The P0859 code is triggered when the traction control system sends a signal to the engine control module (ECM) that is higher than expected.
The traction control system is designed to prevent wheel slip during acceleration by reducing engine power or applying the brakes to individual wheels. The ECM monitors the traction control input signal to ensure it is within a specified range. If the signal is higher than expected, the ECM sets the P0859 code.
• Traction control light illuminated
• Reduced engine performance
• Loss of traction control functionality
• Faulty traction control module
• Wiring issues such as shorts or open circuits
• Faulty wheel speed sensors
ECM: Engine Control Module
ABS: Anti-lock Braking System
• Use an OBD-II scanner to confirm the code.
• Inspect the traction control module and wiring for damage.
• Test the wheel speed sensors for proper operation.
• Repair or replace faulty wiring or connectors.
• Replace the traction control module if defective.
• Replace faulty wheel speed sensors.
• OBD-II scanner
• Multimeter
• Basic hand tools
$150 - $500
Moderate
• Honda Accord
• Toyota Camry
• Ford F-150
• Regular maintenance of the traction control system
• Inspect wiring and connectors periodically
• Ensure wheel speed sensors are clean and functional
Sensor Issue
• Do not ignore the traction control light.
• Consult a professional mechanic if unsure about repairs.
Check with the vehicle manufacturer for specific warranty coverage related to the traction control system.
This code has been associated with traction control system issues in vehicles manufactured since the early 2000s.
Moderate – It is important to address this issue to maintain vehicle safety and performance.
Driving with a malfunctioning traction control system can be dangerous, especially in adverse weather conditions.
• Vehicle must be on a flat surface.
• Ensure the engine is off before performing electrical tests.
The traction control module is typically located near the engine bay or integrated with the ABS module.
Q: Can I drive with a P0859 code?
A: It's possible to drive, but it's not recommended as it may affect vehicle safety.
Q: How do I reset the traction control light?
A: Fix the underlying issue first, then use an OBD-II scanner to clear the code.
Pro · Four-system diagnostics
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Chassis and ABS faults usually need a scanner that can read brake-system data directly.
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