battery problem / TRANS FAILSAFE MODE

[Smeeagain]

I had an issue this morning which Ive resolved but thought it worth posting for the benefit of others.

When I went out to start the car this morning (2004 X%E53 3.0 D Sport) the battery was almost flat and struggling to turn over. Just as I thought the battery was about to die it fired up but "TRANS FAILSAFE MODE" appeared on the dashboard. Not entirely sure what this was, but realising it was some kind of safe mode and presumably ok to drive (at least carefully and slowly) I set off. I soon realised that the safe mode puts some kind of limits on the gearbox - it was leek it was in a single gear, not first as I got it up to speed, but never changing up gear). I also could not select manual

I have no idea why the battery was flat - I do have the vintage of starter that drains the battery and just every so often (like every two or three months) it can appear sluggish on cranking over. I can only assume an internal light or whatever was maybe left open, boot latch not secured etc

Anyway I soon realised that the drop in voltage would have bugerred up the electronics hence the failsafe mode. So a quick trip online and got the reset methodology.

Apologies for the CAPS - cut and pasted from elsewhere

HOLD GAS PEDAL DOWN. TURN THE KEY TO THE NUMBER TWO. CONTINUE TO HOLD THE GAS PEDAL DOWN FOR THIRTY SECONDS.RELEASE THE GAS PEDAL AND PRESS THE BRAKE PEDAL FOR TEN SECONDS. NOW YOU CAN TURN THE VEHICLE ON.

It worked first time. I then gave it a bit of a run to assist with charging and when I got it back home it gave me the perfect excuse to try out the CTEK MULTI XS 3600 charger i bought a couple of weeks ago - as recommended on here - two and half hours later showing a full charge.

Whether or not its all in the mind I'm not sure but the electronics reset seems to have left he gearbox appearing to run more smoothly than before I had the problem ?

Fingers crossed should be ok tomorrow morning

[Sanj]

This is the one we've been used to for the dreaded 'lurch' issue - think it's been described as a 'gearbox soft reset'.

Having read what you 've had and what you've done, it does make sense that this method should be applied.

I had this happen to me over 2 years ago (again, low/dead battery) and not being so clued up I ended up taking it to the $tealer (thankfully I 'blagged' my way to a goodwill gesture - late Saturday afternoon before the shop closed). They were looking to charge me for a complete gearbox overhaul after trying with their own computer to rest the box, 4th time lucky for me. Was VERY close.

This is a great tip as the error appears so often, with so many - thanks!

[brewer]

Yep, had the very same in first year of ownership. Luckily was still with BMW callout service so the guy did the reset and jump started mine. Was scary at the time though!

smee - just as an aside, when charging via the Ctek, did you connect to terminal in engine bay or direct to battery in boot?

Brewer

[Smeeagain]

I used the charging points - is that wrong ?

[brewer]

No idea! I just felt I got a better charge from direct connect to the battery rather than the positive charge point in the engine bay. But a lot more convenient under the bonnet!

[Smeeagain]

I guess it depends what you mean by a 'better' charge - I just went by the 'fully charged' indicator on the CTEK

[CondorX5]

Have seen this question about using the charging points in the engine bay before and general consensus is that its fine to do this - its just an easier way of accessing the battery terminals, after all!

[Blanky]

[quote="CondorX5"]
Have seen this question about using the charging points in the engine bay before and general consensus is that its fine to do this - its just an easier way of accessing the battery terminals, after all!    <!-- s:) -->:)<!-- s:) -->
[/quote]

I bought one of those that can measure battery's CCA (cold cranking Amp?) to check on batteries in our house.
The spec on the battery is 800EN and it is currently measuring 680EN when I connected directly to the battery.  However, when I connected to the terminals in the engine bay, the readings drops to 460EN.  I guess this might be due to the fact that (-) negative terminal is connected to the chassis and there are loss from the rear to the engine bay.
Maybe someone can correct me if I'm wrong, but a vendor once told me not to charge via the terminal in the engine bay.  He told me that it is for starting battery drained car, not ideal for charging because there are losses from this end to the battery side.  And you will waste more energy to charge up your battery.
However, removing everything in the trunk and the spare tire to charge the battery directly is not very practical... though I did it yesterday.... because I left radar running during the whole weekend...  and I had a rather "soft" start on Monday.

[X5Sport]

Charging from under the bonnet is exactly the right thing to do, and is what all the Dealers I've seen doing in the UK.  When you look at the size of the cable running from it to the battery the losses through it and through the body shell will be tiny.  Only if you have corroded/poor connections at either end would there be an issue.

The handbook for mine very specifically states 'Only charge using the connection points under the bonnet and with the engine switched off', so whatever your supplier may have said about it the manufacturer says different.

In a perfect world yes you would remove the battery from the car and charge it on a bench, but as we all know it's a pain to get at, big, and bl@@dy heavy too!  And according to the handbook, unnecessary 

[Rusty]

I agree with X5Sport. The cable from the battery to the under bonnet point is of such a large size, and nigh on direct, there will be no notable losses for the propose of charging. There will be a greater loss from the charger itself to the connector as the cable is much smaller in csa.

Sent from my GT-I9000 using Tapatalk 2

[jaynana]

[quote="Blanky"]
[quote="CondorX5"]
Have seen this question about using the charging points in the engine bay before and general consensus is that its fine to do this - its just an easier way of accessing the battery terminals, after all!    <!-- s:) -->:)<!-- s:) -->
[/quote]

I bought one of those that can measure battery's CCA (cold cranking Amp?) to check on batteries in our house.
The spec on the battery is 800EN and it is currently measuring 680EN when I connected directly to the battery.  However, when I connected to the terminals in the engine bay, the readings drops to 460EN.  I guess this might be due to the fact that (-) negative terminal is connected to the chassis and there are loss from the rear to the engine bay.
Maybe someone can correct me if I'm wrong, but a vendor once told me not to charge via the terminal in the engine bay.  He told me that it is for starting battery drained car, not ideal for charging because there are losses from this end to the battery side.  And you will waste more energy to charge up your battery.
However, removing everything in the trunk and the spare tire to charge the battery directly is not very practical... though I did it yesterday.... because I left radar running during the whole weekend...  and I had a rather "soft" start on Monday.
[/quote]

as said already, and more, this is crap logic the vendor has given you.

the current/amperes required to start a car are massive compared to the trickle current sent to charge. the chassis and the thick cable running from the battery to the front of the car is sufficient even for that 'massive' current required to start the car, so by all means it is more than sufficient for the trickle current sent to charge the battery.
the loss may be high at the stated 'cold cranking amp' level, but i'm confident it will be insignificant when sending a charging trickle current .

[pvr]

My understanding, rightly or wrongly, was also that if you charge directly on the battery you could potentially fry circuits whilst on the charge points, you are protected.

[X5Sport]

Interesting theory.....what was the logic behind that ??? :-\  . 

There are no fuses in between so no protection for either method.  Unless I'm missing something (no pvr the bolts are just fine  )

[Blanky]

[quote="pvr"]
My understanding, rightly or wrongly, was also that if you charge directly on the battery you could potentially fry circuits whilst on the charge points, you are protected.
[/quote]

I think it would be dangerous to charge Non-Maintenance-free (regular lead acid) battery, if u had one in the trunk and not venting it while charging.  because of the hydrogen gas produced while charging.
But damaging the circuits..... I think it is possible if your charger is charging above 14.8V most of the time and you turn you key to position 2 with most electronic running.  Other than that, regular charging shouldn't damage circuits. (while saying that, I had 2 different fault codes after I charge through engine bay charge point with my old charger twice, so I change my charger to a tickle charger and charge directly to the terminal, such a pain.... however, those 2 codes never show up again for 3 month so far O:-)) 

[X5Sport]

Good point about the hydrogen build up, and the standard battery type is vented anyway (as it should have a pipe to the outside) so in theory it shouldn't be a problem. The standard type battery these cars use is an AGM type and sealed.

I don't think I've seen a classic 'wet' battery for a car in some time - unless the cheaper ones still are?  I was under the impression that type was pretty much gone from vehicle use because of the issues in the event of an accident with acid all over the place.

The latest BMW models have to be 'paired' (I think that was the term the BMW ES Tech used) with their fitted battery as the car monitors the charging performance now.

Is 14.8V going to be enough to do damage?  I suppose it might be but it's only 0.4V above the 'correct' alternator setting.  No idea how voltage spike tolerant these modern cars are.  Interesting thought though..