DaveInSaltLake

My thread on the A4 board isn't getting any lovin' so I thought I'd try my luck over here with the 'real' Audi experts. https://forums.audiworld.com/a4/msgs/2704993.phtml

I bought this repo'd 1999 A4q with a leaking ATF pan and the DRN tranny in limp mode. I've replaced the pan, filter, and fluid...and checked for any visible damage to the valve body and all wiring harnesses. All harness connections look good and clean, as does the TCM box and connection.

The tranny works fine when I leave the selector in "3", but whenever it shifts into 4th the rpms rev and the car loses power, much like a clutch slipping...and it goes into limp mode with all the gear letters/numbers on the dash highlighted. Ignition off/on pulls the car OUT of limp mode. I can be coasting down a slight grade with the gear selector in 3rd, move the selector to 4th, even push on the gas to bring the rpms up to what's about right for the vehicle speed in that gear, and put it back into 3rd without going into limp. If I press on the accelerator and rev the engine when it's in 4th gear it goes right into limp mode.

Trans codes include the infamous 00652 and 17101/P0717 for the multi-function switch and trans input speed sensor...but they test OK using the Bentley procedures.

My AudiVW tool software shows that the input speed sensor goes haywire when it hits limp mode, not surprising if Clutch E is bad. It comes back to just about vehicle speed when I let off the gas and coast.

The output tests and electrical tests in Bentley are within specs. In the "Frequent Damages" section of the trans section it states that Clutch E is suspect if there's hard shifting and slipping in 4th and 5th gears.

This post: https://forums.audiworld.com/a4/msgs/2674786.phtml indicates that few people bother repairing Clutch E. This is one data point...is it truly representative of the general trend?

Given the proper fluid level and the full range of Bentley testing, what other options do I have? Any ideas?


Are there any other explanations for these symptoms?

Could a bad MFS and/or transmission input speed sensor cause these symptoms (per the DTCs)? (I'm doubting it, but I don't have much experience troubleshooting transmissions.)

The other thing that I just recalled is that the tiptronic feature doesn't seem to work. I don't really know how it's supposed to work, but it can't be that complicated. I wonder if it's related somehow.

DaveInSaltLake

by pulling shifter magnets from a junked A4 and reinstalling where they'd fallen off.

Tip now works using the buttons on the steering wheel, so I can actually get the car into 5th gear. The engine will rev in 5th without any creating any significant torque from the transmission, just like 4th gear.

This points to Clutch E parts more and more.

Anyone have a good reference for tearing into automatic transmissions? I've not done it before.