As to Alldata, it is a data system not a diagnostic system.
Your tech has used some method to talk to the car but without a code book I can't tell what he talked to. Since you were worried about ASR, I presume the codes are from there.
If there is concern that the DI controller (which one there are two) has a problem it should be consulted. ASR is the opposite of ABS, the system is looking for wheels that are accelerating faster than the others (instead of slower as in ABS). When faced with the wheel that is loosing traction the system aplies brakes on the offending wheel and reduces torque. It reduces torque by backing off timing (thus the need to talk to DIs) and reducing throttle.
Any activity that is not plausible will put the system in a safety mode, including limp home. All systems involved should be scanned and any codes must be evaluated. I almost always throw out codes saying a control unit is bad. Bad control units are almost always lack of communications and usually because they have shut-down for one reason or another.
Dan is right about the statistical nature of the solution to these problems: usually in the throttle assy. Harness problems also can get involved.
To judge a controller bad because no other problem exists is only scientific if the symptom exists while all tests show negative. Since the fault is intermittant no direct diagnostics will work.
Bosch Master, ASE Master, L1
33 years MB technician