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ABC Misdiagnosis?

4K views 3 replies 3 participants last post by  eric242340 
#1 ·
ABC - Visit Workshop malfunction warning on my SL500 (2003). (Not the 'red' warning.)

The authorized repairer disagnosed a faulty strut which was replaced at a shade under $2,000,

When I collected the car, on the turn of the ignition key the 'red' warning appeared for the first time: ABC - Drive Carefully!

The garage now tells me that the ABC pump needs to be replaced: parts and labor $1,900.

I can't get my head round how both the strut and the pump could be faulty and how a problem with the pump wasn't diagnosed in the first place.

Financial carnage.

Any opinions as to what happened here appreciated.
 
#2 · (Edited)
Well firstly ABC is a complex beast and it is very easy, even for experienced tech's to make a mistake on diagnostics, however it is also not unusual with this system for two or even three components to fail at the same time.

When the pump fails there can be a large "knock on" effect. It would appear they found the effect, ie the strut but failed to see the cause ie the pump.

With my customers I tell them when we find the effect but also notify them of not finding the cause and warn them it may require further parts after the effected part has been replaced, and the cause found.
 
#3 ·
That makes a lot of sense, and I do of course have sympathies with those who have to take diagnostic decisions on such a complex system - and there are Star limitations here that complicate further. It does seem possible that the pump defect caused the strut to fail - or perhaps the old pump couldn't 'cope' with the new strut. But I would have thought that Star would show the pump pressure at the very start of the diagnostic sequence: any thoughts on that welcome.

Then another puzzle. After the strut is replaced, the car is driven 10 yards to customer parking bay. I get in, turn the key, and the dash flashes up the 'Red' ABC warning. I can't get my head round that. At the very least, the car couldn't have been checked properly before leaving the workshop.
 
#4 ·
You cannot get a proper pump or line pressure reading when one of the components in the system is defective. They should have replace the defective part, cleared fault codes and then road tested the car.

Upon coming back to the workshop they should then take all the readings and run all the tests again, I feel they did not do this or they would have seen the defective pump at this stage.

Seems to me they were a tad over confident and simply replaced the strut and parked the car up ready for collection.

EDIT; I should say the above is what I would have done and I expect my techs to do the same but I cannot speak for their system.
 
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