Hi, guys. The project is a 1998 Z28 car. The speedometer is not working and that is the only gauge in the cluster that is not working. I have replaced the VSS at the back of the T56 transmission and I have verified that power is getting to that pigtail when the key is forward. Where do I go from here? Does anybody know the pinout for the dash connector that the gauges plug in to? I have another cluster I suppose I could try but if it is indeed the gauge for the speedo that is bad, how do I reset the mileage to what the car actually has? Thanks so much!

 

Bump any advice?

 

I solved all my speedometer issues today by researching. Please PM me if you experiencing a speedometer that is no longer working and I can most likely help you solve the problem. Just wanted people to have some support...

 

My speedo is off about 7mph with stock gearing, stock wheel's stock tire....

any ideas?

 

Post up what you found, it will be a lot more helpful.

 

Here is some info that will help folks. I got lots of PM's on the issue and I'm not sure why I did not just post this up in the beginning...

Essentially, the speed system on the Ls1 Fbodies consists of 3 wires pinned from the PCM. 2 of them run from the pcm to the VSS and after input is gathered, the 3rd runs to the dash and submits class 2 digital data that is translated onto your gauge. In the past with issues like this, I've been extremely successful by pinning out the 2 wires on the PCM that run to the VSS and patching in a wire for each that runs from the pcm to the sensor. Other than the small amount of wire from the patch to the pcm and from the other end to the sensor, you will be bypassing the wiring in between and be using wire you know is legit. For a 99-2002 car, you would need to patch on the following to pins:

These pins reside on the RED C2 Connector

20
LT GRN/BLK

Vehicle Speed Sensor (VSS) Reference Low

21
PPL/WHT

Vehicle Speed Sensor (VSS) Signal

The pin that runs to the dash gauge set I've never seen go bad although it could be bad. Patch into the following pins at the pcm and the other ends at the sensor and let me know what you get. The wiring fails in between the pcm and the sensor more often than some folks realize. I've now seen 3 cars with this issue.

 

Were can I order the vss pigtail from

 

We just did an LS3 swap in a 2000 TA. Now, for whatever reason, we have lost the 5v signal at the tranny for the VSS. We rang out both wires back to the harness and all is good. I'm just not getting the 5v out of the computer with the key on. Thoughts?

 

Hey guys, I'm having issues with my cluster,radio,ac/heat...they all are not working. No lights, (only indicator that comes on is the seat belt light, fuel guage ,battery,and oil guage that is all that does work) I'v checked fuses all ok, any advice?

 

Iam having this same issue with my 99 SS. Made a new harness from pins 20/21 to the vss and no luck. Dont want to buy a new cluster just for the hell of it.

If I used a multimeter at the computer to see if it is sending power, what wire would I check and what would it put out. 5v?

Also, since the #50 wire on the red connector looks to be the speed output wire. Even thought it is a digital signal, is it possible to check this without having a scanner?

 

How did you fix it?? My speedometer don't work

 

If you get this is there anyway u can txt me about my speedometer it's not working 9318013578 thank you!!!!

 

My speedometer in my 95 Z28 is about 10mph faster. And I also dont thinnk the speedometer is stock with the car. I just got the car and am newer to fuel injected cars. Previous car was a 72 Cutlass supreme 350.
So any help would be greatly appreciated

 

I hope someone can help me with this. I am having this exact problem and have tried everything. Short background: I had my T56 rebuilt by Tick. Before the rebuild my speedo worked. After the reinstall its no longer working. These are things i have tried.

-replaced the VSS with duralast part#su1007(original part#10456034 OEM) and #su1289-no luck.
-running a direct jumper wire to ports#20 and #21 on the ECM red side-no luck
-I am using Torque lite on my smart phone to talk directly to the ECM and it shows connection to the sensor but not registering a MPH and giving 0500 trouble code.

1 thing i havent done is used a mirror to make sure there is a magnetic pick up in the trans. I am really hoping this is not the case. Any suggestions? I am ready to try dam near anything at this point.


***Ok wanted to post this up for anyone having this issue. After trouble shooting the issue with Jeremy at Tick i was able to resolve the issue on my own. I did use my smart phone to snap a pick of the VSS pick up for Tick to confirm its in there and not free spinning. I moved around bunch of wires in the center console and buttoned everything up. I notice everything started working when i went to move the car around the driveway. Here is the email i sent to TICK.

Hey Jeremy,

Just wanted to let you know i was able to resolve the issue. When i
bought this car the headlight switch on the dash never lit up at
night. I figured it was a burned out bulb. Well after moving some
wires around near the gear shift underneath the center console the
speedometer and the headlight switch both started working. So i have
some bad wiring i have to track down, more than likely a bad ground.
Dont know if it mattered much but i removed the new VSS and put the
old one back in since it was a wiring issue. I noticed the old VSS sat
further in the port due to the "O" ring being more broken in. The
newer ones with fresh "O"rings did not sit so far in. Dont know if
that makes a difference or not but its one detail i did notice. Thanks
again.

-Dan

 

A few weeks ago my master clutch cylinder pushrod broke on a 1998 Camaro 5.7 and I had to have the car towed to Tuffy. Not only did they replace the master cylinder they also replaced the clutch, the slave cylinder and the line connecting the two. $2,157 and 17 days later when I picked up the car the clutch and T56 transmission worked great but the speedometer no longer worked but all other gauges do. I crawled under the car and not only was the pigtail not plugged into the speed sensor, there was no pigtail in sight. Prior to bringing the car in the speedometer worked fine. Tuffy is now claiming there was no pigtail and that the speedometer is somehow controlled by the computer without being connected to the speed sensor on the T56?

 

ok what's the trick to getting the speedometer working without replacing the vss? 02 z28 68,xxx 6 speed ls1!

 

Found diagram of transmission online showing connections showing connections. Faxed diagram to Tuffy, and they plugged the speedo sensor wire into the right socket and it now works.

 

 

Hey man I’m new here so I did a 6 speed swap on my 98 trans am everything else is good but speed speedometer won’t work, Coolant gauge

 

i have a 97 v6 camaro and the speedometer, odometer, and cruise don’t work, when I drove the car home it worked but now it won’t any suggestions?