I recently had 3:73s installed in my 99 A4 C5. I drove the car sparingly for a couple of weeks before having the PCM reprogrammed. I did not notice it slipping during that time, but the shift points were way off. I did throw the 1870 code about three times and the tranny shifted hard at maximum line pressure without slippage. I always cleared the code as soon as possible.

I had a tuner program the PCM for the 3:73 gears, shorten the shift duration to about 0.4 seconds, remove traction control and torque management, and change a couple of part throttle shift points. The line pressure was left at stock settings. Later that day, after a three hour+ drive home, I noticed the tranny starting to slip during the 1st to 2nd shift. I had not noticed this before.

Is it possible that something in the programming could cause an A4 to start slipping that soon, or is it most likely a coincidence with a tranny problem I already had? I am going to have a beefed up tranny put in, but I would like to be sure that the PCM programming will not cause this to happen again.

Thanks for any opinions.

Dennis Roberts

 

0.4 is not a short setting for adaptation time -
it's mighty long, comparable to my stock tables
0.4 2-3, 0.5 3-4) and will allow the trans to be
lazy. Try something like 0.1, 0.15 (or just zero).

Playing with pressures may make for slip and if
you start to hear it, you might want to go back to
the stock settings again and take small cuts at it
so you learn what not to do.

 

Thanks for the reply. I think I am going to ask the tuner to reflash it to stock values except for the 3:73 adjustments. Then I will get Hptuners to tweak the settings.

Dennis