XSeries-forum

Hi, this is my first post so may be a little sketchy.
Twice now over 4 months my E70 4.8 M Sport has come up with the same fault but 4 months apart. First time was after driving car for about 100 miles, Transmission, 4x4, stability etc warnings all came on at same time. Pulled over and I Drive screen message said do not turn off engine and continue to destination carefully. Drove ok apart from pulling away from a stop had to rev it harder than normal. Got home and googled fault, forums said to ignore message on I Drive and turn engine off and restart it, problem should disappear, which it did. 4 months later having driven just 10 miles same fault happened but this time shut down engine and it wouldn't restart. When start button pushed no sign of engine turn over, eventually battery low warning came on. Jump started car and all was ok again. Anyone any idea what is causing this? I can't find the same exact fault on forums. I have had a new battery fitted, just before the first happening but all codes were cleared and car told it had a new battery. Second time was about 2 weeks after the battery negative lead was replaced. Are these just coincidences? Checked the alternator and it kicking out 14.5 volts and battery at 12v. Just bought a jump starter in case it happens again. Is it Transmission related or power? Be very grateful for any info, great car but if it keeps doing it , it may have to go. Thanks in advance.
Andy

The battery voltage should be higher - at least 12.5-12.6. Was the new battery coded to the car the right type? As in AGM again, or a different type and rating if the battery type was different?

It sounds like a main power issue. The ‘no shutdown’ error could well have been low battery so the car knew turning it off meant no restart. Engine dying would very likely have been a lack of power too.

What was the fault in the battery negative lead? It has the Intelligent Battery System built into it, did that fail?

What error codes were recorded? Without any sort of error code it’s very difficult to suggest, but you should get all of the connections to main power (positive and negative) checked. It could be the charge point connection under the bonnet is loose or corroded. It needs to be both clean and very tight. Same for the leads at the alternator and starter, and negative strap from the engine to the body.

My X6 will ‘load shed’ non-critical items if the battery starts to go, followed by an ‘excess discharge’ warning. Are you getting that at all?

Hi,
Thanks for the reply. The new battery was the only one recommended for my car by the garage that I took it to, I had already ordered it via Eurocarparts. It's an Exide Premium EA 1000 100 AH Wet Lead Acid. The new battery was coded to the car. I took the battery reading after the car had been sat for 3 days. The alternator was pushing out 14.2 volts, left car running for a while and battery went up to 12.5. The negative lead was changed like for like, the old one was cracked right through where it goes over the terminal, wouldn't tighten fully. Haven't had chance to check fault codes yet ! will book it in soonest. I hope your'e right and agree it sounds power related but why it happen after I had driven 100 miles with the alternator working fine. Will check all the connections as you advised. Cd player has swapped itself to radio a couple of times and the clock has gone off and had to be reset a couple of times too. Power low and shed them I presume. I do, do mainly short journeys but also some longer ones. I have just bought the jump starter which was a good recommended one and also ordered a Noco battery charger. I will charge battery once a month as recommended by another answer on different forum. Understand as you say power is an issue with these beasts. I will see if anything transpires and I get to bottom of it. Thank you for suggestions.

Andy

Bosch, Exide, Yuasa and others are all good batteries. E70s are often fitted with AGM batteries (all my BMWs are or have been since 2004), but fitting a wet battery makes no real difference as long as it’s coded in correctly. AGM is good for Stop/Start equipped cars but often chosen because it’s safer in a crash - no acid leaks. The charging voltages are different - hence the coding must be correct. Fully charged and ‘off-load’ such when the car is asleep (and measured under the bonnet 4 hours after last use) your battery should read 13.2 to 13.6V when fully charged. The difference being related to battery age.

Short journeys will kill these batteries due to the electrical load these cars pull - mine is over 60A doing nothing. It takes at least 20 mins just to put the starting charge back!

A lot of us use CTEK Conditioners (same as BMW themselves badge and offer) as they offer up to 8-stage charging cycles and if you have the car off the road, can be left permanently connected. I use a 3.8A version for the 3-series throughout its winter storage and a 10A version on the X6 if that isn’t being used.

Thanks for the additional info. I will look after battery as best I can, if it still plays up then I can at least rule that out. Easy to tell I suppose if the clock dumps and entertainment has a mind of it's own. Thanks again, will post any updates, may help others to solve similar issues.

OK, had a spare couple of hours and just worked my way through all 31 forum pages. Read everything related to any of my symptoms, conclusion is battery related problem. I do mostly short trips and when I do put my old charger on it, it's always in the red and I didn't charge it for long. On the second occasion all the faults came on I had been sat at idle only, showing my son how various things worked. I had no idea how power drawing these cars are. Basically don't do anything without the engine running. If you hoover, open all the doors at the same time and turn off the interior lights, if you go shopping empty car one door at a time and close it straight away or turn off interior lights. Obviously if you do look after battery properly like I will do from now on battery drain is less of an issue. I would recommend buying a good recommended Jump Starter and the same for a Battery Charger. Mine is the 4.8 so I'm not taking any chances. Still be doing some checks of my own on battery and charging system but going in garage at end of month for code reads etc and confirm battery coded to car. Hopefully this be end of my woes with this fault.
If you do have any of these symptoms / warnings go for battery problem first, clock going to ----, cd player turns itself to radio and go to garage picture comes up, Driving along loads of warnings come up including : Transmission fault, 4x4 fault, proceed with caution, car systems degraded and I Drive screen tells you not to switch off engine because it won't restart. Mine did restart the first time it happened but I had driven with the faults for around 50 miles before I turned it off and restarted it, alternator must have recharged battery enough but second time I turned off engine straight away and tried to restart it, car was having none of it. Eventually started with a jump start, all warnings went away. Warning on jump start, once connected to donor car leave connected for a good 5 minutes before attempting to start yours, this was only way mine would start. Good luck and I've got my fingers crossed all now ok.

Quick update. Had a diagnostics and code reader on car today, several power related codes found but had had the Battery Negative cable replaced so all could have been related to that and not my fault. Cleared all the codes and ran a diagnostics on all systems, battery, alternator etc etc, all seem fine at present. Will drive around for a few days and put diagnostics on again, see what I get.

Another update: Car has just done it again, travelled as per the second time around 7/8 miles and all the previous warnings, Transmission, 4x4, DSC etc etc. came on. Didn't shut down engine this time as per the I Drive message. Drove it home, shut it off and tried to restart it, this time it did restart without any problems, with no battery messages. Only warning that would not clear was the SOS icon. Put the diagnostics tool on it and had codes for Transmission and 4x4 system undervoltage. Cleared these and the SOS. Checked battery condition and voltage and that the battery was still coded to the car correctly, all good. Ran a diagnostics on the alternator output using the wave form and the actual voltage output, with no loads on the waveform was a little erratic and varied between 14.4 and 14.0 but when I put on the headlights and wipers at same time the voltage dropped to 13. Thought this a little low, have ordered a new voltage regulator and see if any improvement. Still got car booked in garage for Diff and TC oil change, will get all connections for battery, alternator, earth strap etc checked. Going for the voltage regulator rather than just brushes as a belt and braces precaution. If no improvement in voltage output I can rule out the regulator and sell on the old one. Any one got any other ideas or suggestions? Will be glad to get to the bottom of this for my sanity and back to driving without having the gremlins in my head.

Voltage not far off, but given the negative lead has been replaced is it properly tightened and clean?

Varying voltage levels and an unclean waveform certainly points at a regulator issue. 14.4V is right for AGM but 13V is too low for both AGM and LA types. What happens if you give it some real load like heater, heated rear window etc?

Hi,
Thanks for reply. The car did this the first time before the negative lead was replaced. I have checked it though and all ok. The battery I have fitted at the moment is LA and brand new, originally it had an AGM when I bought it but it went completely flat so I replaced it. I did code the battery to the car and told car it had been replaced. I have kept the battery charged up and it seems to be holding fine, no low battery messages and the car starts ok now after all the warnings. I have not tried to read the output voltage yet with heavy loads on but all 3 times I have had the warnings come on there has only been light loads on. I have used the Fast windscreen demist and had cd player on and wipers and not had the fault. Coincidence maybe but on all 3 occasions I have had all the warnings, the car has been sat at idle for a few minutes shortly before it happens but the first time it happened I had been driving for around 100 miles, pulled into services for a short time with engine at idle and drove only about 500 yards when Blackpool illuminations happened. At time no loads on car and battery should have been charged by alternator for the 100 miles. I am fairly confident as you say that it is most likely the voltage regulator causing my issue. Change it when it turns up and see what happens. Thanks again.

Further update, voltage regulator sent was wrong one, be wary of online sellers drop down menu. I contacted BMW dealership in the end and they gave me correct pt number. Any way car went in local garage for transfer case oil and diff oil change and engine oil flush and change, mechanic as advised checked all connections for corrosion and tightness. Turns out the alternator was swimming in oil and needed to be replaced, no good just cleaning and changing regulator. Found electric water fan was leaking too, explain topping up cooling a little too often. I thought I had cured the oil leaks by replacing rocker cover gaskets, which had gone brittle and were leaking badly, indicated by burning oil smell through vents. Happened on my E46 too. Apparently timing cover gasket leaking oil directly onto alternator. Waiting for new alternator and other bits to turn up from Germany but mechanic pretty sure oil leaking onto alternator not doing it any favours and could well be causing the undervoltage and warnings. Should get car back later this week, will give it some good runs and keep fingers crossed that all woes are over with this problem. Concentrate then on sorting SOS warning and the climate control kicking out hot air when cold selected. Car has been a trial so far and only had it since April, no surprise previous owner passed it on. I won't give up easy but finances and wife may make decision for me. Really like car though and all the money put into it would be wasted if I don't have a bit more endurance though eh! Bought it for £7200 and spent nearly £1500 so far, that's without this latest visit to garage which is going to be circa £ 600 - £700.
Anyway more to come, hopefully all my reports will save others some money. BFN.

Got car back today complete with new alternator, Diff service, TC service, electric fan water pipe, timing cover gasket and another transmission oil change. Will clear all fault codes tomorrow and see how we go. Just for info alternator was £200, timing cover gasket £15.00, electric fan pipe £30.00. Transmission oil was from Westway, Lifeguard 6. Cost £35.00 for each 5 litres. Got everything crossed that those warnings stay away now. Don't want to be paranoid again. Will post updates soon.

More tales of woe, still got SOS warning, not done much about it yet though. Transmission fail came on after transmission oil change, turns out to be not enough oil in system. Chirpy sound from lower engine, thought it was replacement alternator, turns out to be water pump worn and tensioner shot. Another bloody oil leak, this time vacuum pump got hair line crack, £100 for reconditioned one with 2 months warranty. Water pump £250.00. What next? Not had chance to give it a good run yet to see if original faults are cleared. Garage said previous owners not looked after car at all. Will see what happens next and update.

ok, got car back from garage again, new water pump, recon vacuum pump etc. £554.00 with labour. Checked transmission oil again and the tensioner changed. Still not looked at SOS fault yet, least of my worries. Hopefully now all I have to now is drive, couple of months should confirm whether original fault fixed or not.
Just putting up new post about repeater indicators. Not as easy to change as you might think.

3 weeks on and no warnings yet. Haven't done a long trip yet but last couple of times they all came on were on journeys below 10 miles. Fingers crossed all sorted. Still got pesky SOS warning though, separate issue though.