Tuesday, April 30, 2013
How to Test an ABS Speed Sensor
1. Elevate the rear of the vehicle in a secure position with a car jack, and place it on jack stands. Place wheel blocks around the front tires. Remove the rear tires to test the ABS speed sensors.
2. Locate where the engines electrical wiring harness meets the sensors electrical wiring harness. This is generally in proximity and secured around the strut housing in the wheel well in the front and the shocks in the rear.
3. Remove the sensor from its position using a quarter-inch ratchet with an 8- to 10-mm socket, which is generally located by the heat shield on the caliper.
4. Examine the end of the sensor. If it looks like a big fur ball at the end, then too much contamination is disrupting the sensor.
5. Spray the sensor with brake cleaner and wipe with the rag to remove contamination. Contamination on the sensor can send erroneous signals to the computer.
6. Disconnect the engine harness from the sensor harness. Set the voltage meter to Ohms, and connect the positive and negative terminals of the voltage meter to the input and output on the sensor. If the voltage meter registers as infinity, then the sensor has failed and needs to be replaced.
7. Switch the meter back to Volts, if you do not see an infinity in the ohms setting. If the voltage meter reads above 5 volts, it is starting to fail and can cause intermittent problems. If the voltage meter reads below 5 volts, check the knock sensor for corrosion and check the electrical connections leading to the knock sensor.
