ABS SENSOR OUTPUT VOLTAGE MEASUREMENT

Lift up the vehicle and release the parking brake.

Disconnect the ABS-ECU connector B-03, and measure the output voltage at the harness side connector.

Manually turn the wheel to be measured 1/2 to 1 turn/second. Measure the output voltage with a voltmeter or oscilloscope.

Terminal No.
Front left	Front right	Rear left	Rear right
16	9	27	11
26	10	28	17

Output voltage:
42 mV or higher when measured using a multimeter
120 mVP-P or higher when measured using a oscilloscope

If the output voltage is lower than that given above, the cause may be the following, so check or replace the wheel speed sensor if necessary.

ABS sensor pole piece-to-ABS rotor clearance too large

Faulty ABS sensor

WAVE PATTERN INSPECTION USING AN OSCILLOSCOPE

After checking the connection of the wheel speed sensor harness and the connector, take a reading of the output voltage wave patterns for each wheel speed sensor using an oscilloscope as follows.
Start the engine, the transmission selector lever to D range, and then spin the wheel.

NOTE:

You can also take a reading of the wave pattern by actually driving the vehicle in this condition.

The output voltage will be lower when the wheel speed is lower, and will become higher as the wheel speed becomes higher.

POINTS IN WAVEFORM MEASUREMENT
Symptom	Probable causes	Remedy
Too small or zero waveform amplitude	Faulty ABS sensor	Replace sensor
Waveform amplitude fluctuates excessively (This is no problem if the minimum amplitude is 100 mV or more)	Axle hub eccentric or with large runout	Replace hub
	Faulty ABS-ECU earth	Repair harness
Noisy or disturbed waveform	Open circuit in ABS sensor	Replace sensor
	Open circuit in harness	Repair harness
	Incorrectly mounted ABS sensor	Mount correctly
	ABS rotor with missing or damaged teeth	Replace ABS rotor

NOTE: The ABS sensor cable moves in relation to motion of the front or rear suspension. Therefore, it is likely that it has an open circuit only when driving on rough roads but it functions normally when driving on smooth roads. It is recommended to observe sensor output voltage waveform also under special conditions, such as driving on a rough road.