Hi all
My diesel 520 failed to start after a boxing day shopping trip. The iDrive was reporting fuel pump failure then cruise control failure, then reported it was launching some kind of Start Assist program.
Upon pressing the start button the engine was attempting to turn but was not firing. The symbol came up on the dash board showing the car up on a ramp, suggesting I should go to the garage, what a useful idea :-)
BMW promised to send someone to rescue me. We sat there for over an hour but no one came so I tried to start it again and sure enough it did start. Looked in the iDrive faults area and it had no reported faults and the car was back to normal - weird I thought, a minute ago the fuel pump was allegedly broken, the Cruise control had a fault and the start assist program had been started. Now the car is back to normal with no record of a problem??
The following morning I attempted to start the car again and was back to square one, fuel pump, cruise control faults, start assist message and the car on the ramp symbol on the dash board. So I called BMW Emergency Service, 4 hours later the BMW rescue service themselves arrive. He tried to start it and thank goodness it was still exhibiting the failures.
He plugged in the diagnostics and although the car was struggling to start and was reporting failures to me there was no communication with my car from his laptop!!! The BMW man said "I've seen this before", popped the bonnet up, pulled all the plastic covers out, pulled out a relay, put in a new one then the car started perfectly normally.
Did the diagnostics thing again and it communicated but there were no fault codes in the system. How ridiculous?!?! So if the car had started on his arrival there would be nothing for him to go on and I would have probably been charged for wasting their time etc etc.
Not to mention that if he hadn't seen this sticking relay issue before another garage/technician might have started changing the components being reported as faulty on the iDrive, fuel pump etc.
Apparently this relay provided power to the ECU, instead of the fault system reporting a no power scenario it reported loads of other stuff and apparently can't store a fault because the ECU has no power. Goodness knows what computer was throwing up all of the iDrive messages then??
Just thought i'd post this nice story in case some other poor unsuspecting BMW owners fall foul to this sticking relay issue.
Adam
Edited by Webmaster on 02/01/2009 at 13:11
|
The real story is that rather than get hung up on the diagnostics, the technician relied on his experience and knowledge to quickly rectify the issue.
In this age of computer driven diagnostics and the nightmares that can bring, i suggest a round of applause for that man!
|
Indeed, I was very lucky to get the BMW Customer Service agent. The day before they were going to send a local break down contractor to me, the one didn't turn up!
I was with him on his laptop (probably getting on his nerves) and saw the communications failure, then saw the 'No Codes' response after he'd fixed it.
|
|
|
|
|
Yes, this is the general problem with computer diagnostics - garages can rely too much upon their basic descriptions of the fault without first checking the basics. "Fuel pump not functioning" should be replaced with "Fuel pump not functioning, or you've got a chafed wire, or you've a sticking relay, or a fuse, etc.". You need to take everything with a pinch of salt unless the failure is obvious.
|
What is really required to repair todays cars is: 20 years mechanical experience, 20 years electrical experience,be aged under 30, have a solid background with pc's, Attend courses throughout each year to grasp the latest systems, be clairvoyant, hope no-one else has touched it before you, been near it with jumpleads, or listened to anyone in the pub.
Peter
|
|
there is a lot more things that i could add to the list, you cant buy experience
|
|
In this case I think that the OP was quite lucky. Firstly the first person to touch the car was the BMW roadside technician, rather than a generic roadside technician. Secondly as luck would have it he had seen this same fault before and he knew what the symptoms were telling him, he didn't have to work it out with a logical diagnosis or even make rough stabs in the dark until he did something magical that made the car work, as he admitted he had seen it before and he knew what the fault was. I dare say that even if the car had gone into a BMW dealership a trained technician might have been struggling with the fault from the outset. It wasn't a simple plug the computer in and follow what it says job, it was one where the experince of seeing it before counted.
|
Precisely! Which is the reason I posted in the first place so hopefully someone in the future who has suffered big time by actually replacing fuel pump etc etc might read this post, swap the relay and save themselves a lot more grief.
I just can't believe that BMW's diagnostics system is that useless, even on a car which still has a new car warranty, that it can't return a message suggesting the ECU has no power. How ridiculous.
|
errr
the ecu cant log a "I have no power" fault becuase - well - it has no power to do so.
It can make a brave stab at "i have reduced power" or complain painfully "i have too much power"
|
I'm not saying the ECU should 'log' a no power scenario, i'm saying that when BMW plug in their flashy laptop and the ECU hasn't booted/powered up it should provide a more sensible fault description than "fuel pump fault" "Cruise Control Fault".
Just a suggestion but maybe "ECU not responding" or something like that maybe more sensible than the above.
|
|
the flashy lap top thingy i like that well it does say no communication which in experiance means no power which usually means relay because its intermitter every one thinks a tech plugs in a flashy lap top and it tells you broken wire under fuse box colour blue wire 32 , we would be with out a job if that was the case, thank god u got the bm tech instead of road side u would be ranting a whole lot more lol
|
|
|
|
|
hi, adam
I have exactly the same issue you are having i have spent over £400 already!!!!!!!
is it possible to contact you via telephone
|
|
Hi,
did you manage to get this resolved as i have exactly the same prob and have spent enough trying to get it fixed,
Thanks
Gurps
|
|
|
|
|
Hi Adam,
I have a 530D and have exactly the same problem, have changed glow plugs, ECU, ran latest updates - spent £600 already !
If possible can you let me know which relay was replaced, was it relay 5 as BMW want to know specifics ?
Thanks
Gurps
|
|
hi,i have the same problem does anyone know what relay it is that may need replacing?????cheers ady
|
|
|
|
|
hi,do you know what relay it is?????cheers ady i have same problem and its doing my head in spending money and getting no where!!!!!!!
|
|
|
