chevyman1217

I have a 1994 camaro with a 3.4L and the t-5 5 speed that im having issues with the speedometer. I have been using my GPS for the speedometer because at 80 it says im doing 15 mph the odometer and trip meter both work just slow because the speedometer isnt working correctly.

Any ideas on what to do to fix this issue?

any help would be great

Injuneer

Is it possible someone replaced the PCM with a unit from an automatic trans car, and did not reprogram it to work with the T5 manual?

Have you scanned it for codes to see if there is one for the vehicle speed sensor (VSS)?

chevyman1217

i dont have any codes stored or coming up do you think it might be the pcm?

Injuneer

With the V8 engines there is a difference in the number of VSS pulses per output shaft rev. The 4L60E has a 40 tooth reluctor and the T56 has a 17 tooth. I don't know about the V6 and the T5 trans. In the S10 pickups it also used a 40 tooth reluctor.

Do you know if the trans or the PCM has been swapped? Have you had this problem as long as you've owned the car?

chevyman1217

im not sure if it has been swapped i have only had the car a couple weeks. I have been wanting one of this body style for a while and this was the cleanest of all the ones I looked at. The only thing that I could find wrong with it was the speedo issue and the gas guage hasn't worked right since I put a new fuel pump in it. It also sounds like a bad bearing in the tranny when you down **** and the rpm's go up. When you take it out of gear or engage the clutch the noise goes away. Not sure what that is either haven't taken the tranny out yet to find out. I'm wanting to switch it to the T56 6 speed but not sure if I can do that and keep the hopped up v-6. do you know anything about doing that kind of swap?

Steven Jackson

I'm having trouble with my Speedo sensor as well...I just replaced it but found out that a mousexy chewed through the wires on top of the transmission...does anyone know where the wires run from the Speedo sensor...Ive tried to follow it but I can't findo any diagrams online...I just need to find out where to connect the wires again....

Injuneer

The main engine harness wraps around the back of the engine. A branch drops off and goes down the left (driver) side of the bell housing and trans, to the VSS on the tailshaft. See attached .pdf

The VSS has two wires, one yellow and one purple. The yellow wire attaches to PCM pin B30, the purple to pin B29.