VSS manual trans location

Does a manual trans 3rd gen have a separate vss? Or does the speedo register off the wheel sensors? I’m researching a possible 9” rear swap in conjunction with my 4 link build. I know I will lose abs, traction control, and atrac. Really curious if I will lose the speedo, and what problems will occur the ECU

 

It never really describes it but from the looks of it, it uses the average value of the functioning sensors. So the speedo will work, you'll just have a Christmas tree for lights.

If you want to test it, disconnect the rear axle harness, its easy to get to, just follow the wires up.

 

I actually did that already. Drove the truck around the block, and completely forgot to look at the speedo. I was paying attention to how the truck drove. It seemed to drive fine. Now I have the front suspension removed, and can’t drive it. Christmas tree dash is an accurate description. I was going with a Solo xlt kit for the front, which deletes the sensors with the Dana 44 hub setup. Thanks for the info.

 

With the Christmas tree, you will also lose cruise control. But, the new version of vF Tuner allows you to bypass most any DTC.

 

Good info about the Vf tuner. I wasnt aware of that capability. I will be reading through that thread to get up to speed. Looks like I wont have any wheel sensors at all, if I follow through with the Solo kit. Any other problems to be aware of without a speedo?

 

It is a new feature since last Wednesday.

You need a speedo of some sort? If you're not getting speed, you won't get odometer mileage also.

 

If he doesn't have any veh speed input to the ECU, won't there be issues with several tables in the calibration? I can think of at least 7 lol.
Hmm, the truck always thinks it's stopped.. but the clutch is out, trans isn't in neutral..

 

I would think so, but it is unfamiliar territory.

 

If you want to keep the functionality.... The rear axle is easy, swap a Tundra 9.5"/10.5" or Land Cruiser 9.5". The speed sensors are compatible. The front is a little more difficult... but not impossible.

 

I was thinking about using a gps speedo. Odometer would start from 0 but thats ok. Would of course like to avoid it all together of possible.

 

Thats what I thought. Can you share those 7 tables that you’re aware of?

 

It will be interesting to know how it all works out in the end.

 

I will call Diamond, I know they build all those axles mentioned.

 

At a basic noob vF tuner level (that's me), you're going to have issues with the truck not knowing which gear map to use (or using the 1st gear map all the time). If you're tuned and already using Mat's single torque map patch, this won't be an issue..

So, Primary Throttle Efficiency Target gear maps 1 through 6, and Accelerator Request to Airload. That one uses vehicle speed raw value.
There are most likely more.

 

I left a voicemail, and email with Diamond. Do you have anymore info on the Tundra/LC swap? I cant find anyone thats done this on a 3rd gen.

 

I’m tuned, but it’s probably an outdated tune 1.05 91 FOB. I’m definitely lagging behind with whats going on with Ovtune, and Vftuner. Idk what the single torque patch is all about, but I will look into it. Sounds like the ECU will need speed either way, if I’m understanding correctly.

 

The ECU is definitely looking for speed input for more than Speedo, ODO, speed limiter, traction control, abs, etc ...that's for sure. Whether or not the lack of this input is going to cause serious driveability issues, up to and including limp mode, is anyone's guess.

Edit: Here's one of the maps that uses raw veh speed input directly (this is my modded version, the stock one is all over the place)

 

I just thought of something else.. the "Skid Control" ECU uses the wheel speed sensor inputs to develop a speed signal that is sent via CAN bus to the cluster.

 

I just got off the phone with Solo. I was told they have built many 3rd gens with their xlt front kit, 9” rears, 0 ABS system, and haven’t had any problems with driveability. I guess they somehow picked up a speed signal with the t case for automatic shift points. I also got the standard dont listen to anyone on forums speech. Lol Idk what to do here.

 

If they say they can do it, and will guarantee it works, I won't stand in their way.

The 2nd and 3rd use the same wheel speed sensors, so 2nd gen swaps should give the required info. Still need to deal with the front.