SMKNGTA

I have an 89 GTA with a 99 LS1 and t56 and I cant get the speedo to work. I have R50 connected to to c207 K, and the buffer box has been bypassed and disconnected by connecting C and F. I dont get any reading on my speedo at all. All of my other gauges work as they should. Im wondering if there is anything I am missing here. I had a t56 in the car before the LS1 swap and the speedo worked while running through a dakota digital box. I know I can set it up to run the same way but I know the LS1 computer is more then capable of the job. Any help would be very appreciated.

Thanks

86White_T/A305

Odd,it should work.I wired my tach,speedo and oil pres. directly at the back of the cluster harness to the ecm.The ecm has to see the vss from the t56 to give you speedo on the cluster if you want it to function without the dakota box.

SMKNGTA

Yeah, it should work. Ive read all of Pocket's info countless times through this process among other info and it all points to it being wired correctly. I still need to to wire up my DLC so I can hook up a scanner to make sure it is reading the vss.

86White_T/A305

Yea id double check how you reconnected the vss to the ecm,you can also use a multimeter on the 2 vss wires to check if you are getting signal.Just raise the car on jack stands,probe both wires and see if you get ac voltage and slowly increase speed should increase voltage.Then you know the vss is fine going to the ecm.Also the ecm must be tuned for t56 not auto or you wont get it working either from what Ive been told when my ecm was first tuned.

SMKNGTA

I plan on checking with a DVOM. The ecm, engine and harness are all from the same car which was a t56 car. I also had the ecm tuned by Frost as a ls1 t56 in a thirdgen to remove all of the unused equipment.

Pocket

iTrader: (24)

Is the Dakota box still wired in? If so, bypass it and try again. You want a strait shot from the PCM to speedometer

SMKNGTA

Pocket
I have the box still connected to some old wiring that I need to remove but it shouldnt be connected to anything anymore since the trans side of the LS1 harness is untouched, but i will double check to make sure. Also, thank you for taking the time to give us all of the great lsx swap info.

86White_T/A305

I thought the dakota box was already out of the car.if its still in the wired up to the speedo then its your issue.Box has to go and then report back to us when you know for sure its just a single wire going directly to the speedo from the ecm,and the 2 vss wires from the trans to the ecm with no other splices it should start working at that point.