P0500 code, no tach and flashing overdrive light
 

Fellow orgers,
After much research (searching this forum), I would like to share the corrective action I've done to correct these issues. I'm doing this in case someone has a similar issue or runs into this problem in the future.

Car: 98SE automatic with 160K miles

Problem: Tachometer and cruise control stopped working. I get the overdrive light flashing 16 times at start-up and the check engine light with code P0500 (VSS sensor) and P0600 (Communications interruption). Speedometer works fine and car runs good.

After mutiple code resets, checking wire connections and sensors, I went to the JY and replaced the entire gauge assembly. All codes, flashing lights fixed. Tach and cruise now work.

True root cause: By switching out gauges from the old assembly with the new assembly, was able to determine the old tach was functional in the new assembly, but the original speedometer, although functional, was not sending a signal to the tachometer. I believe the cruise wasn't working due to no signal from the tach or speedometer.

Lesson to pass on: For those with a code P0500 and no working tach, the solution may be to change out only your speedometer unit. It does take some work and may be easier to change out the entire gauge assembly.

Hope this helps anyone who has struggled with similar symptoms.:D