Have you tried checking the vehicle speed sensor?
The diagnosis found here addresses an inoperative gauge condition. If the problem being diagnosed is related to gauge accuracy, be certain to confirm that the problem is with the gauge and not with an incorrect speedometer pinion gear, axle ratio, or tire size. Refer to Transmission and Drivetrain for more information on the speedometer pinion gear.
Perform the vehicle speed sensor test. If OK, go to Step 2. If not OK, replace the faulty vehicle speed sensor.
Disconnect and isolate the battery negative cable. Unplug the vehicle speed sensor wire harness connector, the daytime running lamp module wire harness connector, and the PCM wire harness connector B (white). Remove the instrument cluster bezel and the cluster assembly. Unplug the printed circuit wire harness connector 1.
Probe the vehicle speed sensor signal circuit cavity of the printed circuit wire harness connector 1. Check for continuity to a good ground. There should be no continuity If OK, go to Step 4. If not OK, repair the short circuit as required.
Check for continuity between the vehicle speed sensor signal circuit cavities of the printed circuit wire harness connector 1 and the vehicle speed sensor wire harness connector. There should be continuity. If OK, replace the faulty speedometer. If not OK, repair the open circuit as required.
Monday, March 28th, 2011 AT 8:37 AM