I'm working on a 2018 US Spec Golf Comfortline with ACC . The ACC mode I have is what they call "Follow To Stop" (FTS). This mode will stop the car in the traffic for like 2 sec and then send a chime to force you to brake with your foot. It's needless to say that this ACC mode is useless in traffic situation. After much reading, I found out that the main reason behind this is that the car is not equiped with an electromechanical park brake (EPB). If you own a MQB equiped with an EPB (Golf R, Golf wagon, Tiguan, Euro spec Golf etc..) then you get the ACC mode which is called "Stop And Go" (SAG). This is the real deal as it can handle all traffic situation. I have experience with both the EURO and US spec version of it and it does a very good job.
As I said, you need the EPB for one particular reason : if the car is stopped in a traffic situation for more than 3 minutes, for safety purpose, the car will engage the EPB until you resume from the stopped traffic situation. That's, to my knowledge, the only reason why you get the Follow To Stop instead of the Stop And Go version.
I'm trying to convert the ACC from a FTS to a SAG version. The first thing I tried was to put a CAN gateway between the Bosch radar (which handle the ACC control) and change the byte that has the ACC mode in it. As expected, the car complain about it because the Car Gateway was probably doing a safety and logical check on it. Then after studying the coding in VCDS , I found out that there's 3 places where coding need to be checked to enable the EPB : ECM, ABS and ACC. ECM and ACC coding explicitely show theses options and of course, checking them doesn't work. From diagrams, it seems to start from the ABS module. I then studied the coding since there's no real help in the VCDS long coder window. The ABS coding, as I learned, does contained part of the VIN in it to prevent swapping coding from one car to another. By comparing many codings with and without EPB, I was able to locate and confirm 6 bytes that are directly related to the VIN. I was also able to locate 4 potentials bits that could be directly related to the EPB. Software and hardware version in my US spec ABS module is the same the EURO spec module with EPB, so it would make sense that it could be enabled with coding (although, it might complain). So I tried changing these 4 bits one after the other, and only one of the 4 was actually accepted. This was probbaly not the right one as I was still not able to enable the EPB in the ACC and the ECM module.
So, does everything above make sense? Did I missed anything ? Does some of you has any experience in either changing the ACC mode, ABS coding for EPB or anything that could help me getting this to work ?
Thanks for any help
As I said, you need the EPB for one particular reason : if the car is stopped in a traffic situation for more than 3 minutes, for safety purpose, the car will engage the EPB until you resume from the stopped traffic situation. That's, to my knowledge, the only reason why you get the Follow To Stop instead of the Stop And Go version.
I'm trying to convert the ACC from a FTS to a SAG version. The first thing I tried was to put a CAN gateway between the Bosch radar (which handle the ACC control) and change the byte that has the ACC mode in it. As expected, the car complain about it because the Car Gateway was probably doing a safety and logical check on it. Then after studying the coding in VCDS , I found out that there's 3 places where coding need to be checked to enable the EPB : ECM, ABS and ACC. ECM and ACC coding explicitely show theses options and of course, checking them doesn't work. From diagrams, it seems to start from the ABS module. I then studied the coding since there's no real help in the VCDS long coder window. The ABS coding, as I learned, does contained part of the VIN in it to prevent swapping coding from one car to another. By comparing many codings with and without EPB, I was able to locate and confirm 6 bytes that are directly related to the VIN. I was also able to locate 4 potentials bits that could be directly related to the EPB. Software and hardware version in my US spec ABS module is the same the EURO spec module with EPB, so it would make sense that it could be enabled with coding (although, it might complain). So I tried changing these 4 bits one after the other, and only one of the 4 was actually accepted. This was probbaly not the right one as I was still not able to enable the EPB in the ACC and the ECM module.
So, does everything above make sense? Did I missed anything ? Does some of you has any experience in either changing the ACC mode, ABS coding for EPB or anything that could help me getting this to work ?
Thanks for any help
