A/C Brainteaser- Does it need a Star to reset?

[phill993]

Just had A/C regassed after replacement of a damaged condenser/dryer. The system holds pressure at 0.95g as per the spec and shows no signs of leaks. HOWEVER, A/C button light is off, when button is pressed the light flashes 3 or 4 times then goes out and A/C doesn't operate. (Though it is difficult to tell in this weather!)

The handbook says that on this car (W211 Estate late 2007 facelift model) the A/C button light is illuminated when the A/C is running / Off when not running and flashes if there is a loss of gas pressure.

The guy who regassed the system was totally bemused and after a long while checking the entire system with a sniffer and ultraviolet lamp, rang one of his mates for advice. This guy told him that the Merc A/C system needs to be dealer RESET (presumably with the STAR) after loosing gas pressure completely.

Does anyone here with a knowledge of the STAR system know if the A/C does need to be reset after being worked on? If so, is it posible to reset without the STAR? I have checked the codes using an Autel EU702 reader and the car is showing a completely clear code bank.

As the gas pressure is holding up, does anyone have any other faut finding suggestions/ideas/techniques?

 

[BlackC55]

Yes, it will need the fault memory erasing with a Star

 

[phill993]

Yes, it will need the fault memory erasing with a Star

Any ideas as to why it doesnt show up as a fault on the Autel Fault code reader?