Stuck in 3rd (Limp Mode?) and Speedometer problem

[paulywallydoalawladay]

New to me 1999 Mazda b3000 2x4, found that the tranny was replaced at some point, has "2004 Ranger" painted on the side and has three unused sensors that my truck does not have the wiring for.

I had no speedometer and no odometer, O/d light flashing. Only code is P0500. Also did not have working wipers, dome lights or door chime...

So I replaced the VSS at the rear diff and had no change after a short drive.
Then I Ordered a used GEM module from ebay and installed today. Now my wipers and dome lights and everything work but my speedometer is reading higher speeds than Im actually traveling and about 15mph at idle...

Transmission feels like it's stuck in about 3rd gear. I figure this is limp mode for when the speedo was not being read. Reverse works great, 2nd feels the same as drive, and 1st feels locked up, truck wont move at all.

My question now is:

I don't know how long the previous owner drove the truck around in limp mode but I'm going to say it was probably for a long time. So, are there tranny solenoids I should start checking or does this computer just need time to catch up with the speedo and get its self to start shifting again?

I checked fluid and its bright red, and at the proper level when truck is hot.

 

[Curious Hound]

Won't go above third gear sounds like a torque converter lockup problem to me. Might be the solenoid that isn't hooked up. The speedometer problem could be a totally different issue.

 

[Burnsy]

Maybe the OUTPUT speed sensor that bolts into the side/rear top of the transmission, if your tranny has one....its the same shape as the vss but smaller....its held on with one bolt that has a star pattern fitting, maybe use a mirror to see it to get your tool on it as it faces kind of "up" and isn't really visible, but its not too tough just takes a little patience

 

[Burnsy]

Maybe the OUTPUT speed sensor that bolts into the side/rear top of the transmission, if your tranny has one....its the same shape as the vss but smaller....its held on with one bolt that has a star pattern fitting, maybe use a mirror to see it to get your tool on it as it faces kind of "up" and isn't really visible, but its not too tough just takes a little patience

Sometimes the auto parts stores computers don't really differentiate between the vss and the oss , they will both show up on their screen at the same time as speed sensors regardless of how they look them up.............the only differentiating thing sometimes is a line that ll read "goes into the side of the transmission" or " goes into the rear axle(differential)".......but YOU may have to look for this on their screen while they've got it up etc.......and also, like I said, the oss is smaller, but shaped exactly the same , you can always compare size