chook89

I'm having an issue with my 2002 Allroad that I can not figure out how to fix. It started over the past winter, I'm up in North Dakota and the cold temps took a toll on the car. The compressor gave out around -40 degrees and the car was throwing a fault for the front left level sensor. As soon as the temps warmed up I replaced the compressor and the front left level sensor (G78), along with the pig tail for the sensor. I also found air leaks in both of the front air lines and replaced both lines. The compressor is very strong and the car had no faults when I started it up.

After accomplishing all of the above items I started the car and the back end lifted, but the front end continued to be all the way down. I checked the VAG COM and saw that the readings from the front sensors are way off (Sensor 1 read -127mm, sensor 2 read 74mm). I then attempted to complete the 402 procedures to get it back to where it should be. The 402 procedure never gets past the "wait" portion. The car thinks its at level two, it tries to go down to level one but no change ever happens and then it times out and the VCDS errors out. But if I do not wait I can enter the values in and save them. Here is the part I can't get around, I can enter the correct height for sensor one, which currently is measured at 280mm, it accepts that number and allows me to proceed. Its sensor two that I am running into issues with. The actual height of sensor two is 300mm, but the lowest number I can input that VCDS says is valid is 482mm. If I enter 482 I can finish the 402 procedure without any other issues. If I enter the actual number it says its invalid and errors out. During this time I had two faults, one was the position was unknown, the other was it was out of limits, both faults cleared once I completed the 402 procedures.

I completed the procedure using 482 for sensor two to see if there would be any change to the car. Now the air compressor turns on and sounds like it is doing something, but there is no change to any wheel and I can not find anything mechanically wrong with the system. If I run an output test now, nothing happens. The front end doesn't raise or lower, sometimes the back end raises and lowers. All of the output test since trying the 402 have not passed. I know the valves are opening when lowering, I can hear them engage, but no air is being pumped to the front end and the numbers the sensors think they are at are still very wrong.

I tried the 402 with the car running, not running, changed the numbers I input and tried with it re-coded. I am out of ideas. If anyone has any ideas or suggestions I would really appreciate it.