The speedometer is out and the o/d off light is flashing

JAKEZOC

MEMBER
1999 FORD RANGER
6 CYL
4WD
AUTOMATIC
135,000 MILES

I pulled it down the driveway to test and found the speedometer is out and the o/d off light is flashing. I did some research and found that this is normally caused by the abs sensor in the rear diff (also acts as the vss through gem) so I replaced it. This didnt fix a thing. I checked all the wiring and it looked good. Have not been able to test it yet but will if no other ideas. Could this problem be caused by the G.E.M or the P.C.M?

1 Reply

KASEKENNY

MECHANIC
18,907 POSTS

We need to start with what codes are there. These could be related but we need to start with codes and then figuring out one of the issues and if it fixes both then that is a bonus.

https://www.2carpros.com/articles/checking-a-service-engine-soon-or-check-engine-light-on-or-flashing

https://youtu.be/rTtAnsOlZU4

Basically, the way this works is the ABS sensor in the rear diff that you replaced sends the speed signal to the ABS module and then that sends it to the GEM and then the GEM sends that to the various other modules including the speedometer.

I attached the info below on this.

Please let us know what you find with the codes, and we can go from there. Thanks

Image (Click to make bigger)