Wheel Speed Sensor: Testing and Inspection

PURPOSE OF TEST

The wheel speed sensor output test measures the relative signal strength of the front and rear wheel speed sensors. Signal strength is measured by reading the WSS OUTPUT meter while spinning the selected wheel. In order to measure output consistently, output should be read from the meter only when the SPEED RANGE indicator is on and not flickering.

HOW TO PERFORM TEST

The test procedure for performing the Wheel Speed Sensor Output test is described below and is summarized in the above illustration.

1. Ignition must be on when performing this and all other tests with the J 36210 tester.

2. Raise car on a frame contact hoist so that the wheel to be tested is off of the ground. Install the J 36210 tester and J 36210-90 adapter; turn ignition on. The READY Light Emitting Diode (LED) must be ON.

3. Select WHEEL SPEED SENSOR test mode on the test selector buttons.

4. Specify wheel to be tested with the SELECT switch.

5. Have an assistant spin the selected wheel until the SPEED RANGE indicator (red) remains on without flickering. The wheel should be turned at a constant speed.

6. Read wheel speed sensor output on the WSS OUTPUT meter. As the wheel is turned, watch the meter needle and note any excessive bounce or flutter which would indicate variations in signal strength.

POSSIBLE RESULTS

Normal Operation

As the wheel is spun, the needle should remain steady at a relatively constant value. Acceptable output ranges are included in the Diagnostic Trouble Trees.

Low Output

A low output condition is encountered when the needle remains steady at a value less than the acceptable minimums specified in the diagnostic information

Excessive Needle Bounce

Large fluctuations in the meter reading as the wheel is turned at a constant speed may indicate excessive toothed sensor ring runout or damage. Needle fluctuations over a range greater than 1.0 units on the meter scale should be investigated.