Speed Sensor

Control Relay:

Sensor Level Test:

Sensor Change Test:

Diagnostic Code Reading:

PRETEST PROCEDURE

1. Remove the bolts from the control relay and remove. Disconnecting the check connector.
2. Put the parking brake on and start the engine.
3. Within 2 seconds, push the brake pedal 4 to 6 times.
4. The warning light should be blinking about every 1/4 second or about 4 times a second.


SENSOR LEVEL TEST

After performing the PRETEST PROCEDURE above, drive the vehicle at about 2.5-3.7 m.p.h. in a straight line. The warning light should turn on after a one second delay. If the warning light turns on while the vehicle is within the specified speed range, the check is completed.

NOTE: When the vehicle speed exceeds 3.7 m.p.h. and the warning light blinks again, the speed sensors are OK.

If while driving at speeds above or below 2.5-3.7 m.p.h., the warning light should turn on without blinking. Go to READING DIAGNOSTIC CODES below to find the defective part and repair or replace it.


SENSOR SIGNAL CHANGE TEST

While driving the vehicle at about 28.0-34.2 m.p.h. in a straight line, the warning light should turn on after a one second delay. If the warning light turns on while the vehicle is within the specified speed range, the check is completed. NOTE: When the vehicle speed is not within the specified range and the warning light blinks again, the sensor rotors are OK.

If while driving at speeds above or below 28.0-34.2 m.p.h., the warning light should turn on without blinking. Go to READING DIAGNOSTIC CODES below to find the defective part and repair or replace it.


READING DIAGNOSTIC CODES

After performing the above test, bring the vehicle to a stop. The warning light will begin to blink the diagnostic codes. The diagnostic codes can be read by counting the number of times that the warning light flashes and the time between flashes. Codes are separated by a 2.5-4.0 second delay, the digits in the two digit code are .5 seconds each and are separated from each other by a 1.5 second delay.

CAUTION: Do not put the parking brake on, press the brake pedal more than 16 times or turn the ignition off. Diagnostic codes could be lost if any of these things are done.