Hello all, long time follower, first time poster and I'm looking for a little help. I have searched this forum and the web for hours over the course of this diagnosis/repair job and finally have decided to post. I will try to keep the description of my problem as short as possible while providing all pertinent information.

My vehicle is a 2001 A6 Quattro sedan with 2.8 liter engine and ZF 5HP19 FLA automatic transmission with 200,000 miles. The original transmission (EKD) failed with these symptoms: Will not shift out of park, once I freed the shift lock solenoid the shifter would move but the car would not drive in any gear, torque converter was always locked, the TCU was completely immersed in water.

The first thing I did was to clean out the cowl panel drain and replace the TCU with one of the same code: 4BO 927 156 AK. All symptoms stayed the same except that the shift lock solenoid was now working properly. I then proceeded to install a low mileage replacement transmission (EKX) and torque converter along with new seals, filter and genuine fluid. An experienced Audi technician had assured me that the EKX was a compatible replacement for the original EKD, even though many others told me that I should go with the same code. Once I had everything buttoned up and triple checked the fluid level, I took it for a ride. The car would shift hard and quickly go into safe mode. There was also a loud grinding noise. I had the Audi tech take a quick look at it and he felt that the replacement transmission was bad.

While going through all of the transmission connectors and wiring to make sure there were no faults there, I found that some of the TCU harness pins were corroded so I broke down the connector and replaced all of the corroded pins with new ones from another TCU pigtail. All splices were made using high quality solder joints and all pins went back into the correct locations.

I then proceeded to swap the EXK trans with a DPT. Now, there is no noise, it drives and seems to shift fine through all gears until the engine load reaches about 40% or higher then it slams into 4th gear, limp mode... I am getting two VAG codes: 17100 - Transmission Input Speed Sensor (G182) P0716 - 35-10 - Implausible Signal - Intermittent, along with: 17114 - Gear Ratio Monitoring P0730 - 35-00 - Incorrect Gear Ratio. I decided to run live VCDS Advanced Measuring Values while driving the car and everything looks ok except the for Transmission Input Speed (G182). I noticed that the RPM value displayed was 0 until after it shifted into second gear or higher. For some reason, when in first gear, the TCU reads no RPMs on the input shaft! It would make sense that if that value was off, it would also throw the Gear Ratio Monitoring code.

After all of this, I found some information about how the transmissions with hydraulic control e17, have a inductive speed sensor and transmissions with hydraulic control E18/2 have a Hall effect speed sensor, along with the computer being different. Does anyone know how to tell which hydraulic control is in these transmissions? I would assume that if I used an incompatible transmission that I would have more fault codes and more issues.

Any input is truly and greatly appreciated. Thanks in advance!

 

It is a 2000 model year, NOT 2001! Sorry...

Any ideas?

 

I wish I could offer, what I would consider to be definitive assistance.

my best guess, based on what you have posted so far and the journey you have undertaken, is that you have a wiring problem, or the problem exists with an incompatible TCU. for the most part, you seem to have a better handle on your transmission issue than I can have.

best of luck getting it sorted