LWillmann

Friend of mine converter from an A4 to a T56, but his speedo doesn't work.

I've searched and found where people have swapped rear ends to get the speedo calibrated again, but didn't find anything about using a different year transmission.

What do we need to get to fix his speedo so it works right?

The car is a 1993 Z28, the transmission came out of a 1997.

1SlowFormula

I am not a Manual expert and I can't remember how the speedo is calibrated on the 93.. But I can tell you the M6 in 93 has different ratio's then the M6 in 94+ so if the calibration is done through a chip or something make sure you tell the tuner that is a new tranny and not to use the ratio's for 93...

LWillmann

I had heard that the speedo in the 93's is cable driven, rather than PCM driven.

respectirocz

i heard that later model 3rd gens were no longer cable driven, so why would they go back to cable for the 93? i might have my info wrong

LWillmann

I could be wrong as well. But that's why I'm asking here.

madwolf

The speedometer is electrical on 93s, but those ECMs are very limited as far as speedometer calibration is concerned.
If he kept the 2.73s or 3.23s in his car, then he should be able to make it work by swapping in an M6 chip or by having the chip burned with an M6 tune.

LWillmann

The chip has an M6 tune in it, or it's supposed to anyway.

I will have to get under the car and make sure that the wiring for the sensor is connected properly.

I believe that it does still have the stock gears in it, but I'm not 100% on that.

madwolf

Yes, double check all the wiring. A4 cars, like M6 cars in 93 had both 2.73 and 3.23 gears, so there were two different tunes available for them. Which gears does he have? What is the broadcast code on the M6 tune he used?

By the way, I know of another person having the exact same problem.

I'm putting a 97 tranny in my 93, but I'll be converting to a 94 PCM because I have 4.10s in it and I would've needed the speedometer calibration box anyway.

LWillmann

Not sure on what gears he has.

I've been trying to locate info on what wires should connect where for the 93's but I'm not having any luck.

Not sure on the broadcast code. The tune he bought came from PCMforless.

JKDZ28

hey lee, thanks for the help

my gears are 3.23

their was this electrical connecter under the car, if i remember correctly it had 5 prongs.... there were NO plug in for it

i don't know if that makes any diff. with the speedo or not

LWillmann

That 5 prong connector was for the A4's speed sensor I think. So one of those wires needs to be hooked to the T56, and I think the PCM will get speed signal. We'll look at that this weekend.

JKDZ28

sounds good dude, thanks

Alvin@pcmforless.com

All you need to do is just snip off the VSS pigtail from the auto and get a VSS pigtail from a 6 speed car. The prom has to be recalibrated for the 6 speed so if he had it tuned for a AUTO than he will have to have it retuned for a manual.

Its really simple and straight forward. I have a new T56 in my factory auto 93