I had all the ABS sensors cleaned-up, the frequency of the ESP fault was reduced, still getting the P2135 code and engine going into low power mode, thank goodness I bought a cheap ODBDII handheld code reader that I carry connected with so I can reset the code when I'm driving at 80mph and suddenly this infamous code shows up bringing me down to 25mph in the middle of rush hour, really dangerous, it should be a safety recall on this. It affects lots of GM based cars like my 2011 9-4 4T BioPower. Follow up steps is either to change all 4 wheel sensors, throttle/pedal sensor, camshaft position sensor, whole throttle assembly, etc. in that order