darrow

Good afternoon

I'm new to this forum but I hope to get some feedback on a few things...

I have a 2005 525D E60 Auto with about 88K miles on the clock. Earlier this week when I started up I had an error which read 'increased battery discharge' and the clock reset itself but the car started ok so I set off to work. The same thinh happened on the way home from work and again the next morning. By the evening however the car was dead - press the starter button and nothing, not even a click. However the lights, radio, door locks etc were all fine.

I called the RAC who tried to jump it and to reset the computer but nothing so I had it recovered to a main dealer.

Today the dealer called me to tell me that the battery was dead and that I needed to pay them £193 for a new battery before they could run the diagnostics - they told me they dont have batteries lying around to use and couldnt use a booster so I had to pay. This is my first question:

Q Does anyone know if it is possible to run the diagnostics by using a battery booster rather than the battery? And does anyone else find it incredible that the main dealer didnt have a spare battery to use to test it? (lets set aside the fact that when I left the car on the back of the flatbed the battery was fully charged and taking a charge according to the RAC

Now they have replaced the battery they tell me only now (from the diagnostics) can they see that the CAS Unit is fried (and that could have happened by jump starting it...)

Q Would anyone else think it normal that they would check the CAS unit before telling me I needed a replacement battery? Surely there is an order in which things should be checked? Strikes me that the reason the diagnostics wouldnt work was due to the fried unit rather than the battery?

Q If a CAS unit is fried would the radio, lights, alarm etc still work normally because they did...before I gave it to the main dealer?

Now I am up to £599+ vAT for the battery, diagnostic check and new CAS + fitting.. They tell me the good news is once the new CAS is fitted they can run the diagnostics and see what the problem was.... this is going to be expensive

Any similar experiences or comments?

pukka

Your battery was most likely dead to start and the CAS could have very well been damaged during the jomp start. A "dead" or very weak battery can still turn on the lights but not start the car. Most places don't keep batteries "lying around" just to use for diagnostics - the very first check would be to test the battery and if not up to par then replace.

I've never heard of checking a car's diagnostics with no battery connected since in many cases the engine has to be running in order to properly read the data - this obviously can't be done without the battery.

You are having a BMW serviced at a BMW DEALER, so yes it will be expensive. But it sounds like they are doing the right thing by you - good luck.

darrow

Thank you Pukka. Your explanation about the car needing to run to diagnose makes sense so I can understand it needs power but surely one of those mobile boosters would have been suffice? Anyway, thanks for your feedback its much appreciated.

Actually I've just remembered that when the RAC technician came out one of the things he said he was going to so was to 'reset the computer' and he disconnected the battery terminals, got a piece of cable and connected two points together (I wasnt paying too much attention) as he did this there was a spark and flash as he had left his van booster cables connected to the points under the bonnet.. I reckon he fried my CAS. Dont know how to prove it but surely there is a claim from somewhere

Anyone have any experience like this?

sanjsanj

A mobile booster would have been enough to start the car and hence run diagnostics. If they couldn't start it with a booster, they should have tried disconnecting the battery and then starting it.

But that's not all!

That RAC mechanic is a douche. If he did what you said, he's shorted out the booster but more importantly, he sent a voltage spike up both your negative and positive terminals which probably did fry your electronics.
Go find that mechanic again and ask (while acting dumb & innocent) "How do you reset the computer if the battery's gone dead?". Record his response and there's your evidence. Long shot I know, but it's £700+ at stake here.

BTW, I think it's written in the T&C's that BMW can't do stuff to your car without asking you for authorisation, so they can't install a new battery and then say hey, pay us for a new battery. They have to ask first...


On a side note, can I have £3k please? You must be minted if you're going to BMW for repairs...

darrow

Thanks sanjsanj. I thought they should have been able to do it from a donor power source of some kind. Just to clarify - they did ask me first but they told me they had no option but to put a new battery in so after some arguing I reluctantly agreed (I have asked them for the old one back though so I will get it checked as I'm not convinced it is dead beyond recovery).
As for the RAC patrol - I emailed the RAC on Friday and just now had a call back to say they are looking into it. I'm convinced he has fried the CAS and possibly even more and if that is the case they should fix it. As I broke down in the work carpark (with CCTV) I can prove if I need to that I drove in in the morning with a working car and the only other person to work on it was the RAC guy - it might even show that he left the cables connected. I'll post any updates here as others might have had similar experiences

As for the £3K - I'd love to but I'm not minted by any means! I had to pick a place to recover my car to at 1am and I chose a BMW garage as I was told by the RAC that if it was recovered home I would then need to pay again (£125 odd) to have it recovered to a garage). I was sure it was a battery drain or the immobilizer or something not so expensive so I figured by saving the £125 I'd be about quits. Anyway, too late now!

Thanks