v8rx7com

I have a 2005 with the 4L65E A4 auto transmission, 3:42 gear swap (was originally a 3:15 gear) and a 3,000 stall torque converter. I have had my car at 2 different tuners. I ask both of them specifically to tune my trans for my new rear gear and 3,000 stall converter, yet I'm still having the same 2 problems:


# 1 - If I take the car for a long drive, I get a code (P0894 - transmission component slipping) and the car shifts hard while hot (1st to 2nd gear), but the car shifts OK when cold.


# 2 - On aggressive launches, my speedo and HUD speed doesn't work until I let off the gas .... (The speedo reads 0 MPH then jumps to the correct speed after I let off the gas).......... if I drive non-aggressively, my speedo and HUD works fine.

I've read:

The speedometer defaults to 0 mph if the software detects a mismatch of engine rpms to vehicle speed. So I'm thinking my speedo problem and P0894 code might be related to the stall converter and/or with the tune not being correct?

I'm trying to figure out if it's still just a tune issue or a mechanical issue?

Anyone have any experience with tuning an A4 with both a higher stall torque converter and a gear change?

Any advice would be appreciated.

jim2092

I have dealt with issues in an A4 when the tune is not changed to match a different rear end in an auto car. Neither of your problems match those issues.

However your first problem could be converter related. Higher stall converters create more heat as they slip more. Among other things, shift firmness needs to be increased in the tune to counter this issue.

You need to verify that your tune contains adjustments for both changes done by a competent tuner.

v8rx7com

I didn't think the second issue was converter related until I noticed my speedo/HUD issue only happens under a certain condition (hard launch from a stop). I'm now thinking what is causing the P0894 code might also be responsible for my speedo/HUD issue (I've already checked the VSS wiring and replaced the VSS sensor).


I took my car to the 2nd "highly recommended" turner after repeatedly getting the P0894 code after the 1st tune (I would clear the code, but the code would eventually return). Since I'm still getting the code after the 2nd tune, I started thinking maybe it's a mechanical issue, but everything I've read (so far) points to an issue with the tune.

I know the obvious answer is to take my car back to the 2nd tuner and have them re-check the tune. However, it took me 2 weeks to get the tune appointment and they are about a 2 hour drive from my house. So I've been reluctant to go that route unless I'm confident that they can resolve the issue.

I really want to get this resolved, but I'm just not sure what my next move should be.

tblu92

You do NOT make a speedo correction on any C5 or C6 when changing gears----Actually most software's will not allow you to--However if your tuner forced it in then that change screws up how your TRANS interprets speed---- not your speedo---There are 2 main tables in your tune for the speedo and trans---1 is for the speedo input pulses and the other is for the trans output sensor pulses---The speedo table will never change the data but changing the trans data will---
Forcing in a change as your tuner did most likely changed the trans output pulses----STOCK is like 429 but if you input 3.42's it will read a crazy number like 2636---
Put all the tables Back to STOCK in the speedo section and those codes will go away
You should however make a "shift point correction" in your TCM It should be like a -8% change to all the shifting points as well as all your TCC lock/unlock points
ALSO with a stall converter--they are known for causing "false misfire codes " so all tuners will massage the misfire tables in the engine file under diagnostics to eliminate those false codes--They simply max out all the misfire tables
2ndly with a stall --tuning tips include:
Deleting the TCC lock and unlock in all gears but 4th gear
Setting the PWM table to 98 in the "minimum" table and to 99 in the "maximum" table this will make the TCC lock up far firmer and create less heat

dennis50nj

you need to set the tc slipage to a a higher number like 4,096, and all c6 a4 speedo read zero on fast launch

jim2092

This will give you a feel for what can be done when converter and rear end changes are made.

http://www.hptuners.com/forum/showth...TCC-TM-(w-Pics)