I just bought a clean little wagon I have wanted forever, but the speedo/odo aren't working. 4cyl. Automatic. D4 is flashing. Check engine light on. I changed VSS, nothing. I changed speedo, nothing. I lifted front wheels and ran it in gear with VSS removed, and center shaft (pin) isn't turning (is it supposed to?). I changed the entire P.S./VSS unit in transaxle with another nicer looking used one, nothing. Please help if you know what's happening!~ THANKS

 

What code is being flashed by TCU? This may help.

Has transmission or engine ever been removed?

The VSS drive key plugs into top end of a short shaft w/ a gear that engages the flywheel (?). If short shaft w/ gear were incorrectly installed, the VSS drive key might not turn. Appears to be a single bolt holds this assy into the transmission.

good luck

 

You may be on to something there. It wasn't turning when I got the car, and it was a ***** to get out. When I put it back in, I just dropped it into the hole and replaced the extended bolt. I didn't know there was a trick to it. I figured if the gear didn't mesh, the assembly wouldn't go into the hole. The guy at the wrecking yard said he thought the tranny was a 93, while the engine is 94. I don't know what TCU code is flashing.

 

I would suspect part may be too short rather than incorrectly installed. You might try to find a 94-97 part and check against yours or replace.

good luck

 

I tried a newer version at the wreckers, but the single bolt which holds it in was in a different spot.

 

Re-check the "pin" - one end is a hex and the other is round with "two" ears/tabs.

The hex end is sticking out of the trans to the VSS - the round end with tabs/ears goes into the trans- The link between the trans on a 93/4th gen and a 94/5th gen is the same part number "78411sm4003".

PS - there are two bolts holding the VSS to the trans - have any pictures of the part you are replacing?

 

How did you determine the VSS key is not turning? This would require elevating front wheels on blocks, and running the trans in forward drive gear.

The reason I ask is you could be chasing wrong problem. You never said what codes were presented; presumably code 17 for ECU (no VSS signal) and code 4 (VSS circuit fault).

If only code 4 you could have a wiring harness error or TCM fault. However, if VSS link is not turning, Code 17 should be present.

good luck

 

Thanks again Tex,

I believe I installed the pin correctly, and when I took the assy out I spun the gear at the bottom by hand, and the pin at the top also spun. However, when installed, the pin doesn't move (I elevated the front wheels and ran the car in DRIVE).
However, I wasn't able to run codes - I've read about using a paper clip or similar (wire) across the two ports near the glovebox, but haven't gotten to that yet.

 

Thanks Moderator Poorman Sir! I believe I put the pin in correctly.

 

BTW, does code 17 mean I have to pull the tranny and install whatever gear is supposed to engage the VSS?