jdk
New Member
- Joined
- June 17, 2003
- Messages
- 1
- Reaction score
- 0
- City, State
- New Mexico
- Year, Model & Trim Level
- '99 XLS
The alternator on my 99 XLS went bezerk and put out 19.2 Volts. Besides frying the radio, the speedometer does not work. After my mechanic put in a new alternator, he tested the speed sensor on the rear diff and it tested OK. Furthermore the ABS works, so the speed signal into the ABS module appears good. So either the problem is in the output from the ABS module or somewhere in the PCM? The automatic tranny still shifts at the right points so maybe the PCM is good. I am tempted to replace the ABS module and see if this fixes the problem. My understanding is that the speed signal goes from the rear diff to the ABS module to the PCM module then to speedometer on the dash. (If this is wrong please let me know!) If I replace the ABS module does it reset itself? Or do I need to flash or reset myself? Any help or advice would be appreciated.