Comprehensive Guide to Repairing ABS and Traction Control Systems

This guide will go over the repairs and what to look for when the ABS and Traction control light come on in your vehicle. We will start with the easy stuff and progress into the more intricate. When these warning lights flash or stay on steadily it means these systems are disabled. Park the car on level ground with the transmission in park, the emergency brake set, turn the engine off. Let's begin!

Possible Supplies

• Brake Fluid
• ABS and Traction Control Scanner
• Voltmeter
• Tool Set
• Gloves and protective eyewear
• Floor Jack
• Lug wrench
• Flashlight

1. Most people don't know this but, if the brake fluid is low in the brake system master cylinder the ABS and Traction control warning lights will come on. Lift the hood to check the fluid level in the master cylinder fluid reservoir.

2. Raise the car up to do a visual inspection of the wheel speed sensor wiring, may times road debris or obstacles can tear the wiring from the wheel speed sensor in which case just repair the wiring or replace the sensor.

3. Locate the fuse panel under the hood, use the fuse panel lid to find the ABS and traction control system fuses, remove them for inspection and replace if blown. If the fuse blows again there is a short circuit somewhere in the system, which is usually the ABS module or pump motor.

4. The ABS and traction control system use the same data port connector as the engine transmission which located under the dash on the drivers side, connect the scanner and follow the prompts to retrieve the code to make the repairs. Once complete the system should clear the codes after a short drive, some European and Japanese models may need to be cleared using the code reader. If the warning lights remain on after the code clearing, it means you still have a problem. You can purchase a code reader capable of reading ABS codes starting at about $22.00 from Amazon.

Since most of the time the problem will be a wheel speed sensor you can test the sensors manually using a voltmeter. Remove the tire to access the sensor and disconnected it, then attach a volt meter and spin the bearing hub, you should get a small amount of AC voltage.

5. If after you have scanned the ABS and Traction control system and you get any of these codes:

C0031 - Front Left Wheel Speed Sensor
C0034 - Front Right Wheel Speed Sensor
C0037 - Rear Left Wheel Speed Sensor
C0040 - Rear Right Wheel Speed Sensor
C0041 - Wheel Speed Sensor Rear Left Range/Performance
C0045 - Wheel Speed Sensor Rear Right Range/Performance
C0046 - Rear Wheel Speed Sensor Circuit Open
C0047 - Rear Wheel Speed Sensor Circuit Range/Performance
C0048 - Rear Wheel Speed Sensor Circuit Low
C0049 - Rear Wheel Speed Sensor Circuit High
C0050 - Wheel Speed Sensor Rear Right Circuit Fault
C0051 - Steering Wheel Angle Sensor Calibration Required

The wheel speed sensor or bearing hub will need to be replaced or wiring repaired. This job is not to difficult and can be done using basic tools and a floor jack.

6. If when scanning a code is presented for a ABS and Traction Control Module failure it will need to be replaced. This is common because of the high pressures the pump motor performs during its operation, it can overheat and fail.

7. These safety systems uses a series (usually 4, one for each wheel) sensing reluctors or stator rings and is what the wheel speed sensors are counting to give feedback data to the ABS/Traction control computer. If this ring gets damaged or dislodged it can cause the system to malfunction. The system may constantly be activated because it thinks the wheel is rotating slower then the others, in this case these rings must be physically inspected, there may be no warning light on for this problem. The location of these stator rings will vary, some are in plan sight as shown below but others can be located internally within the bearing hub or differential housing.

Watch the Video!

Please watch this video of the job being done to glean additional helpful information.

Credits

This guide knowledge base was created by the 2CarPros Team, and by Ken Lavacot: Automobile repair shop owner and certified master automobile technician of over 30 years. If you have question or need help please ask one of our experts we are happy to help. Please visit our 2CarPros YouTube Channel.