AHC pressures

[BVV4]

52 cm hub to rear fender using a tape measure is right on spec, I believe. So you're saying that your scanner should be reflecting zero and it isn't instead it says -11 like mine says -14, correct? So we have the same problem. Someone with more knowledge will have to try to explain. If you go under there and slide the sensor arm up towards the top of the slot will the car raise up higher? Have you tried unbolting the arm and moving it to try to get zero on your scanner?

 

[BVV4]

View attachment 4117231

Yesterday the pressure was 6.9 and 6.2, today for some reason it's 6.6 and 6.0. Measuring the pressure with the temperature sensor disconnected fails, resulting in error C1762.

 

[Magnaman]

Yesterday the pressure was 6.9 and 6.2, today for some reason it's 6.6 and 6.0. Measuring the pressure with the temperature sensor disconnected fails, resulting in error C1762.

 

[Magnaman]

I have never tried disconnecting the temperature sensor. My pressures change around from day to day, but after the engine has been off, my D7 will not pick up the pressures unless you put it in low first. So it's really hard to say what you're starting out with each day.

 

[BVV4]

52 cm hub to rear fender using a tape measure is right on spec, I believe. So you're saying that your scanner should be reflecting zero and it isn't instead it says -11 like mine says -14, correct? So we have the same problem. Someone with more knowledge will have to try to explain. If you go under there and slide the sensor arm up towards the top of the slot will the car raise up higher? Have you tried unbolting the arm and moving it to try to get zero on your scanner?

It raises the wheel to 51 centimeters, but the sensor shows -11. It doesn't raise mine to 0 centimeters according to the sensor, or 52 centimeters from the hub to the fender. So, we probably have different problems.

 

[Magnaman]

It raises the wheel to 51 centimeters, but the sensor shows -11. It doesn't raise mine to 0 centimeters according to the sensor, or 52 centimeters from the hub to the fender. So, we probably have different problems.

It's a very similar problem. Cannot zero it out in the rear based on the sensor reading. Always negative. Maybe someone knows the answer. One thing I have noticed is that rear sensor is extremely sensitive. Just pulling up to a stop gives you a more positive reading then take your foot of the brake for a second and it goes more negative.

 

[BVV4]

I think I've found a solution to the problem of the rear sensor reading being - 11 mm . The AHC control unit has three groups of height sensor values. They are all listed in the TechStream software in the lower right corner. The altitude sensor values that everyone is guided by (in the upper left corner of the program) are provided with corrections. The adjustment values are shown in the "FL, FR, RR Height Adjust" lines. The correct values of the altitude sensors (without adding correction) are given in the lines "FL, FR, RR After Height Adjust". It says that the altitude sensors need to be adjusted using these lines ("FL, FR, RR After Height Adjust"). I don't know why the AHC unit has these adjustments, what they're for, or how to remove them.

 

[Magnaman]

I think I've found a solution to the problem of the rear sensor reading being - 11 mm . The AHC control unit has three groups of height sensor values. They are all listed in the TechStream software in the lower right corner. The altitude sensor values that everyone is guided by (in the upper left corner of the program) are provided with corrections. The adjustment values are shown in the "FL, FR, RR Height Adjust" lines. The correct values of the altitude sensors (without adding correction) are given in the lines "FL, FR, RR After Height Adjust". It says that the altitude sensors need to be adjusted using these lines ("FL, FR, RR After Height Adjust"). I don't know why the AHC unit has these adjustments, what they're for, or how to remove them.

View attachment 4136757

I found the same data on my D7. So it's far more complicated than just looking at the basic heights. At that point I gave up. Maybe someone can explain all this. I think my rear sensor is still around -10 at neutral, but I don't think the pump is constantly running.

 

[BVV4]

Who knows what this utility is for?

 

[BVV4]

In my car, I used this utility to enter arbitrary values greater or less than 300 millimeters and corrected the incorrect rear sensor reading from -12 millimeters to 0. This didn't work with the front sensors. I don't understand the calibration algorithm.

 

[Magnaman]

In my car, I used this utility to enter arbitrary values greater or less than 300 millimeters and corrected the incorrect rear sensor reading from -12 millimeters to 0. This didn't work with the front sensors. I don't understand the calibration algorithm.

Have to try this when I have time. I think you're right you may just be having a calibration issue.