Automotive wiring schematic for rear axle sensor, PSOM, 4WABS an…

PSOM diagram for '96 Bronco. '93-95 Bronco similar.
http://www.revbase.com/BBBMotor/Wd

CHECK SPEED INPUT SIGNAL

NOTE: Only wiring harness end of connector is to be probed.
* Connect Rotunda Digital Volt-Ohmmeter 014-00407 or equivalent to Pin 4 (speed in positive) and Pin 5 (speed in negative) of the PSOM connector (C252).
* Does the voltage increase smoothly and continuously from 0 to approximately 3.5 volts as vehicle (driveshaft) speed increases from 0 to 48 km/h (0 to 30 mph)?
OR:
* If available, a frequency counter may be connected to Pin 4 (Speed in pos) and Pin 5 (Speed in neg).
* Does the displayed frequency of the signal increase smoothly and continuously from 0 to approximately 667 Hz at approximately 48 km/h (30 mph)?
OR:
* If neither a voltmeter nor frequency counter is available, vehicle speed control may be used as a good indicator. If it works normally, then the speedometer module is at least receiving a speed input signal and the wiring and ABS sensor (DY1123, F85Z-9E731-AB) can be assumed to be good.

Rear axle sensor should read 800-1400 Ohms across the pins, and more than 10 Ohms from the metal shell to either pin

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Owner caption November 2003 · Photo 627 of 6546