Wheel Speed Sensor: Testing and Inspection

1. Prepare system for remaining checks as follows:
a. Turn ignition switch to Off position.
b. Depress parking brake pedal.
c. Connect diagnosis check wiring tool No. 09843-18020, or equivalent, to terminals Ts and E1, Tc and E1 of check connector, Fig. 188.

Fig. 188 Check Connector Pin Identification:

d. Do not depress brake pedal.
e. Block wheels and start engine.
2. Ensure the warning light changes from flashing to lighting up for one second, then to flashing again when the following operations are performed:
a. Depress the brake pedal.
b. Release parking brake, then depress parking brake again.
c. On models with TRAC, press brake pedal while shifting transmission lever to position other than "P" or "N."
3. Check speed sensor signal as follows:
a. Release parking brake.
b. Drive vehicle straight forward.
c. Ensure anti-lock warning light flashes or lights up when vehicle is at speeds indicated, Fig. 189.

Fig. 189 Speed Sensor Signal Chart:

d. Check the output voltage of the speed sensor at a vehicle speed of 2.5-3.7 mph.
e. Drive vehicle faster than 50 mph for several seconds.
g. Stop vehicle then read number of flashes, Fig. 190, of the anti-lock warning light and refer to Fig. 191 for diagnostic trouble code identification.

Fig. 190 Speed Sensor Diagnostic Troule Codes:

Fig. 191 Speed Sensor Diagnostic Trouble Code Chart:

h. The warning light will go On for 0.125 second and Off for 0.125 second. If two or more diagnostic trouble codes are identified at the same time, the lowest numbered diagnostic trouble code will be displayed first.