The Suburban is a full-sized sports utility vehicle manufactured by Chevrolet. The 1994 model is from the fourth generation Suburban line, which included several new features such as a fuel-efficient engine. The vehicle speed sensor on the Suburban is a device that monitors the rotational speed of the transmission shaft. Symptoms of a defective vehicle speed sensor include inaccurate speedometer readouts, improper cruise control operations and converter clutch lockup.
Park the Suburban is a safe location on level ground. Raise the rear end of the vehicle with a car jack. Place jack stands at the rear axles to keep the rear of the vehicle elevated. The car should be raised high enough so that the wheels can spin freely.
Open the hood and locate the vehicle speed sensor, which is mounted to the driver side of the transmission, just near the transmission shaft.
Connect a voltmeter to the vehicle speed sensor output wire. Activate the voltmeter and select the "20-volt AC" scale.
Start the engine and place the transmission in drive. Allow the rear wheels to spin while you monitor the voltmeter. Replace the vehicle speed sensor if the voltmeter does not show a readout of 0.5-volt or more.
Perform a similar test to troubleshoot the wires of the vehicle speed sensor. Put the transmission in park and turn off the engine. Disconnect the voltmeter from the vehicle speed sensor. Connect an ohmmeter to the power train module.
Activate the ohmmeter and monitor the readout. Replace the power train module and the attaching wires if the ohmmeter shows a readout more than 0-ohms.
