Can a computer be tested if car has no spark?

That's a nice, fairly new Benz- the dealer can test the computer, and your car is so nice that it deserves the best- most dealers can't be trusted, but, overall, MB and BMW dealers have good service departments- having said all that, It would be unusual for the computer module to have failed that soon- your problem will be fixed by something simpler, I'm thinkin'

jamnblues is right on about your baby being a nice ride and about it being unusual to need computer module and about it is something much simpler but I might draw the line at Most Dealers...., even the good shops shops force good mechanics to embellish the charges because they don't pay them a good wage but the mechanic relies on extra money being paid to him/her for $ charges. (call it a commission.kick-back,bonus) I won't assume MB or BMW dealers are any better unless there is a Head Office Policy forbidding this practice

While we are discussing honesty of dealer charges - any comments out there on how time is billed to the customer ( what the book says it takes vs the time it really took )

Mb dealers charge in the region of £100 per hour according to a website I found, and of course if "the book" says 5 hours, they'll charge you 5 hours even if it only actually takes 2 or 3. With regard to the original question, if you can get your car towed to a garage then do. Any decent garage can work on Mb just as well as the dealers at a fraction of the cost. Yes the dealers stamp in the book looks good but seriously, who cares anymore!!! Make sure the garage you go to has a fault code reader, save yourself a fortune on swapping out random parts and good luck.