Questions and Answers

Infinity Q45 Speedometer Doesn't Work Q. Hi Autorepair, I have a 1990 Infinity Q45 whose speedometer stops working after about six miles of driving. At the same time the power steering quits. Is there a speed sensor on the transmission that may be malfunctioning? The power steering is weighted to the speed of the car and if the speed sensor stops sending signal, the steering has nothing to compute. Correct?

How do I determine if this is the problem, and how do I replace it? Any idea of cost? I hate to go back to the dealer, as I have been previously hosed by them and hence, have little trust in their veracity.

Regards,
Chuck

A. The Vehicle Speed Sensor (VSS) sends a signal to the speedometer and from there to the Power Steering Control Unit. So if the VSS has gone bad, it would kill both the speedometer and power steering.

The VSS is located on the rear right hand side of the transmission. Here's how to test it.

1. Remove the speed sensor, then connect a voltmeter to the terminals as shown in the diagram
2. Rotate the speedometer pinion, reading should be approximately 0.5 volts.

There should also be a DTC 14 stored in the PCM.