What if a garage gives a wrong diagnosis?

[jupiter2step]

I've had recent problems turning on the ignition with both sets of keys:

See here.

Had a brief phone discussion with my indy. He recommended bringing it in tomorrow for a diagnostic, and if nothing showed he could try fitting a new battery control module to see if that cleared things up.

This got me thinking. Suppose he goes ahead and purchases and fits the new module, but the problem persists. Will I still be liable for the cost? And what if he then recommends another part, and the same thing happens?

Don't like going to a franchised dealership to keep an 8 year old car on the road, but it occurred to me where the root of a problem is uncertain, perhaps I would have more protection to avoid unnecessary parts being ordered and fitted?

 

[lxi]

I've had recent problems turning on the ignition with both sets of keys:

See here.

Had a brief phone discussion with my indy. He recommended bringing it in tomorrow for a diagnostic, and if nothing showed he could try fitting a new battery control module to see if that cleared things up.

This got me thinking. Suppose he goes ahead and purchases and fits the new module, but the problem persists. Will I still be liable for the cost? And what if he then recommends another part, and the same thing happens?

Don't like going to a franchised dealership to keep an 8 year old car on the road, but it occurred to me where the root of a problem is uncertain, perhaps I would have more protection to avoid unnecessary parts being ordered and fitted?

Ask him up front

 

[SilverSaloon]

I think an honest garage should state to you beforehand that its possible it may not fix the fault, unless they are certain.

 

[MicB]

Diagnosis is not an exacting science......it is your car that is faulty so you take the risk. Nonetheless a good garage will do what it can to mitigate the costs of incorrect diagnosis and all the more so with an Indy who is much more likely to be interested in maintaining goodwill and its reputation than many main dealers.

Mic

 

[dpbayly]

The thing is as mechanics we dont have a crystal ball, we can work are way back through a system to track down a fault and end up with a possible more than one culprit its rare but dose happen.

What i would normally do is talk with the customer and explain the situation and that there are no more test i can do so the next step is to replace one or the other, i can only advise what i would replace but explain untill i replace a part theres no way to be sure and that the parts are non returnable so would be charged, customers normally understand.

A good example of this was a few months back we had a toyota (diesel) come in that had been at a main dealer for weeks undergoing diagnostics and they could only suggest replacing the fuel pump at a cost of something like £1750 anyway he brought it to us as we quoted a better price to replace the pump, he brought it in and asked if before i change it could have a quick look so i performed a few checks and plugged it in the fault had something to do with rail pressure and after researching it i discovered the fault may be the fuel pressure valve on the pump (a part available from main dealer) the valve seemed to be functioning so i called the dealer and asked if they sell many to which he replied 1 in the past 4 years but i put it to the customer that i would replace that first and there's a risk it may not work and that i would only charge trade on the labour and part if its unsuccessful and we have to then replace the pump, i told him its the route i would go down first as the valve replacement came to under £100 and a replacement pump was around £1400, he gave me the all clear to change the valve and it was a good call i was correct and needless to say he was chuffed to bits and swore he would never use robbing main dealer again to which i replied they probably performed the same tests i did and everything showed it to be the pump and there was no more they could have checked but start recommending pump replacement it would have still cured it as a new pump came with a new valve so he would have been none the wiser just his wallet a little lighter, he still remained adamant he was now a loyal customer of ours for giving him the options that the dealer did not.

I would like to think if i was wrong i would hope he would still have been happy knowing i had done all i could to carry out the repair with his wallet in mind even if it would have cost a little more. So if its a good garage your going too i would like to think they would offer something similar.

 

[Dieselman]

i called the dealer and asked if they sell many to which he replied 1 in the past 4 years

How many pumps had they fitted, where just this valve was faulty?

 

[dpbayly]

How many pumps had they fitted, where just this valve was faulty?

makes you wounder doesn't it.....

 

[Benzster]

I agree. Mine is excellent.

 

[jaymanek]

basically is as dpbayly says...

We explain the situation to customers. Mercedes are terrible with returns, they wont take anything back, especially anything electrical.. So the customer does have to pay..

Car mechanics is a bit like medicine, sometimes you just have to try various things.
Diagnostic machines such as Star are only an aid.
Sometimes parts can be borrowed from other cars or from stock, however with things that are coded or specific to the car, there is often no option but to suck it and see and im afraid the garage cannot be held liable for getting it wrong if they have taken reasonable and logical steps.
Most garages would be closed if this were the case.

In real problem cases where potentially expensive parts may be required, it can often end up being cheaper just to go to the dealer.... this is because they have a system where parts can be ordered on a returnable basis for special cases, even coded parts.
This is not available to independents...

 

[Borys]

It is a problem.
I use a merc specialist and he never let me down since 5 years now.Each problem on a far was fixed with first attempt.Very important to have someone trustworthy and who knows about mercs otherwise game of maybe's.
One of members here posted problem with his w140 middle vents not operating,mechanics they took whole dash out and didn't fix it-solution was the PSE pump faulty and that operates those vents - had that on my w140's (example)
Worst is from mechanics not knowing lol