4th Gen 4 Life

OK here is the deal. I purchased the 94 z a few months back and have been researching all the mods and different things swapped around. Fun right? Anyways I had a trans problem from the start(all gears but 2-4) and finally got around to buying a used 94 f body a4 from a reputable f body chop shop. Well upon removing the old trans I notice pwm on the pump cover? 95 model I assume? I immediately start looking at my PCM wiring for a TCC/PWM wire. Thus being said it is a 94 PCM. Well upon installing the correct trans with new fluids and a new 2500 stall converter the car only has reverse and no forward gears. These are the test I have tried so far: I jacked the rear up and revving while in (D) the wheels will slowly start to turn and once they start rotating fast enough it will catch second. I also unplugged the trans wire harness and like I researched it did have 3rd. But the SES light did not come on while the trans was unplugged? I have noticed in the past that the SES light didn't come on for common known things but has come on before when I got into it a little bit. I have ordered a set of wires to investigate the pcm that I suspect has had a tune in the past. Could the 95 TCC/PWM trans mess with the pcm or did they try to bypass something? Also why no SES light when trans plug is unplugged? All help is really appreciated as I have already invested more money than I wanted to in this car. Also I have not preformed a pressure check on the trans ether? Any help or guidance?

94 Z28 A4 known mods... reworked ported heads/intake. Cam, 3" cat back flowmaster. unknown PCM tune. still researching car. ...

1990 RS HO 305, TH350(shift kit). 4 barrel carb, Cam, Long tube headers.

4th Gen 4 Life

Sorry this is so long. Does anybody have any thought about this or what route they would go to fix a problem like this?

94 Z28 A4 known mods... reworked ported heads/intake. Cam, 3" cat back flowmaster. unknown PCM tune. still researching car. ...

1990 RS HO 305, TH350(shift kit). 4 barrel carb, Cam, Long tube headers.

Injuneer

A lot of the trans codes don't turn on the SES light.

4th Gen 4 Life

So if you unplug the main harness to the trans the SES light may not come on? Also how does a TCC/PWM trans work with a 94 PCM? Could it have messed with the PCM so that the correct 94 60e would not signal to go into drive gears?

94 Z28 A4 known mods... reworked ported heads/intake. Cam, 3" cat back flowmaster. unknown PCM tune. still researching car. ...

1990 RS HO 305, TH350(shift kit). 4 barrel carb, Cam, Long tube headers.

rngilliland

94 and 95s use the same PCM. The program is different. I don't think using a 95 trans in your 94 could damage the PCM. A 95 trans might work on a 94 if you add the missing harness wire and use a 95 program. The wire would go from the blue connector #6 slot to the transmission plug. Since you have a used 94 transmission and don't have any forward gears, I think you have some kind of mechanical problem not a PCM problem.

Injuneer

Good reading in 4L60E interchange issues:

4L60E year differences and interchanges.

12SCNDZ

Using a '95 trans in a '94 will tear the lock up clutch out of the converter and then the 3-4 clutches in the trans. The issue with your original trans was most likely the 2-4 band, though. It has to be applied for 2nd and 4th.
Early 4L60Es are notorious for the aluminum forward pistons cracking. When this happens, it allows fluid to leak past and not apply the forward clutch. This obviously means no forward.
The issue you're having isn't anything electronic. There's nothing electrical in a 4L60E that will prevent it from moving forward. You have an internal transmission failure. Even if a sprag is rolled, you will still have forward in the manual 2nd and 1st ranges. If you have no movement in any forward position, you either have a forward clutch/piston issue, broken input hub, or broken output shaft. I'm betting on it being the forward piston.

Frank