Originally Posted by Jeff@topgearsolutions
There are codes, but JB4 cant read the shadow codes. You would need a BAV tool to read shadow codes.
Only thing to do is wait for the problem, if there is one, to throw a hard code that can be read. I believe the code needs to be present 3 times before it becomes available to read with JB4.
The JB4 reads shadow codes as well as active codes.