Star Machine takes a holiday...

[BenzBoy]

Problem: ABS/ESP/BAS light flashes on the fascia of the ML.

Scenario 1.
Authorised MB dealer connects car to Star Machine and reports steering angle sensor faulty. Recommends replacement of sensor and steering column (integrated unit) @ $3300.
Could it be the brake light switch again (have replaced the switch about 6 times over the last 10 years). No; we replaced that switch with a new type earlier this year as part of the recall programme and it tests OK).

Scenario 2.
Authorised MB dealer connects car to Star Machine and reports brake light switch fault. Recommends replacement of brake light switch @$80 including labour.
Replaces brake light switch and comments - what a strange switch; we have not seen one of these before but it is genuine.

Return to Dealer 1. Could you please test this brake light switch. Yes; it tests as faulty.

Hmmmmm.

Was the Star Machine in Dealer 1 having a holiday?
$3220 saved and 3 weeks later still no sign of warning lamps.

Regards,
Brian

 

[motec 6.9]

Hi Brian they say 1 is born every minute i take it you are not 1 of them. Stay with Dealer 2 they sound more truthful.

 

[Helmet]

This is actually a very common scenario. Steering angle sensors log faults in this model all the time, but rarely need replacement. I'd say the first dealer cleared the faults and the second dealer only saw the stop light switch fault.
Sometimes even with a Star diagnosis its not that easy to diagnose intermittent faults.
Not sure why MB was recalling these cars that have had plenty of stoplight switches replaced over the years? I thought it was a cheap marking ploy to get clients to return to the dealer. Seems the switches they are fitting are no better than the original Mexican ones

 

[Tony66_au]

Many years ago I spent 6 months at a Euro dealership and my job there was to operate the new diagnostic system as the mechanics were not 100% comfortable with it.

The thing was a tad fragile and if you didn't follow the correct sequence it would throw you a curveball and diagnose incorrectly.

Simple things such as KOEO (Key on Engine off) would check different systems and if the car was running it would check a different set of systems entirely.

As this sort of thing was pretty foreign to the guys on the floor I was brought in as I was essentially a Computer guy but had the necessary "Dirty hands" time as a TA elsewhere and in a few days we were saving tons of time on the floor with simple item swapouts that usually took an hour or so and a few heads to sort.

Although the systems were excellent diagnosticians and over time the Mechanics learned to be gentle with the thing and to see it as a good thing there was one old fart who refused to have anything to do with it which was fine as he had amazing diagnostic abilities and knew these cars very well.

Between this guy and myself towards the end of my time there we had a bit of a friendly contest to see who could diagnose the issue correctly and quickly, me with the system and him with 45 years on the tools but along the way he absorbed enough about the diag system to operate it himself and he accepted it as part of his process and we had a laugh about it over a few beers after work on many occasions.

The thing is that with any diagnostic system there is a process that MUST be followed and as cars get increasingly more complicated with interlinked systems the diag process becomes more of a specialist field and my feelings on this is that some of the older mechanics who may be excellent on the tools still don't feel 100% at home with the computer side of fixing cars as it was never taught to them at trade school unlike the guys who are more recently out of their "time".

The trick back then was to read the codes ign on, eng off and then with the engine running and note them down clear the codes and repeat the sequence to see what pops up.
Go for a test run and scope it again if inconclusive and id often have the old bloke along if the issue wasn't straight forward and so between us the issue would be solved and we became good friends from then until his passing some years ago.

The point of this is that any tool is only as good as the bloke holding it and a closed or narrow mind catches less than an open one.

So I'd stick to the workshop that got the result.

Tony

 

[BenzBoy]

And now for the punch line.
I know both dealers well and know them to be highly reputable.
It seems to me it was the Star Machine at fault - or an operator who did not know quite how to use it. Except for the fact that operator 1 who diagnosed the steering angle sensor fault was from M-B head office....hmm!
Cross fingers that the code does not rasie its ugly head again.
Regards,
Brian

 

[Tony66_au]

All the machine does is tell you what it is told by your car.

The rest is up to the service staff.

 

[WGB]

It's going to be fun keeping cars on the road as they age.

For some reason computer logic seems to be taken as absolute an not advice to be interpreted.

I like Helmet's explanation - seems very logical.

Pleased it ended up cheaper than it might have.

Bill