Help ::: 98 740IL Transmission Prog Fault

Dave Plowman (News) wrote:
> In article >,
> zzz > wrote:
> > 1. Appears to be a "mechanical failure not electrical" says the reputable
> > local BMW dealership
>
> If you do a little Googling you should find a mechanical flow chart
> showing what does what on an auto box, and what the symptoms of the
> failure of each component are. For example, the failure of the pump
> results in no drive in either direction in any gear. Failure of the
> various clutch packs and brake bands similarly effects the operation of
> some gears, but as I said before I can't think of the failure of one of
> these which would leave 4th, neutral and reverse needed for the limp home
> mode still operating normally - this is a symptom of electronics failure.
>


Is it anything like if the computer detects anything wrong it just
shuts down? I.e. a small fault might occur but that triggers the
computer to shut down the whole system?

Dealers will hook the car up to the diagnostic system and then say
"computer says no". That is if they know how to do that properly or
indeed want to do it properly. Did they offer to buy your car from you
at a knock down price?!

Like Dave says BMW don't make the boxes and don't support their repair
(or maintenance in most cases) It's like buying a PC at PC World and
expecting them to be able to fix a power supply fault.

In article . com>,
> wrote:
> > Failure of the various clutch packs and brake bands similarly effects
> > the operation of some gears, but as I said before I can't think of the
> > failure of one of these which would leave 4th, neutral and reverse
> > needed for the limp home mode still operating normally - this is a
> > symptom of electronics failure.

> Is it anything like if the computer detects anything wrong it just
> shuts down? I.e. a small fault might occur but that triggers the
> computer to shut down the whole system?

If say your alternator dies, and you continue driving, one of the first
symptoms you'll notice as the battery volts drop is the gearbox goes into
limp home mode. It could be the solenoids need a full '12 volts' to
operate efficiently, so this is why it shuts down earlier than other
electronics on the car.

> Dealers will hook the car up to the diagnostic system and then say
> "computer says no". That is if they know how to do that properly or
> indeed want to do it properly. Did they offer to buy your car from you
> at a knock down price?!

The computer is anything but infallible - and that's assuming the dealer
told the truth about the findings.

> Like Dave says BMW don't make the boxes and don't support their repair
> (or maintenance in most cases)

Mine also farms out AC work and body repairs. Weird, really.

> It's like buying a PC at PC World and expecting them to be able to fix a
> power supply fault.

In that case it's simpler to just fit a new supply as the labour cost to
fix it is likely to exceed it.

Not so with an auto - although it might be at main dealer labour rates if
a full recon is needed.

I've not had a modern ZF apart yet, but I'm told the valve chest and
internal electronics are accessible without removing the box.

--
*A backward poet writes inverse.*

Dave Plowman London SW
To e-mail, change noise into sound.

I have two recommendations for you, one controversial, one not.

1. Top post. Bottom posting is for idiots that can't follow a thread. Top
posting is for people with at least half a brain that can follow a thread,
and therefore get ****ed off at having to scroll down through a bunch of
already read garbage to get to new info.

2. Find yourself a good BMW independent. Try www.bimrs.org for locating
one. They'll be more realistic than the dealer's "time for a new car"
response.

Brett Anderson
KMS- Koala Motorsport




"zzz" > wrote in message
news
> On Thu, 06 Jul 2006 08:46:53 -0500, zzz wrote:
>
>> On Wed, 05 Jul 2006 09:42:31 +0100, R. Mark Clayton wrote:
>>
>>>
>>> "Floyd Rogers" > wrote in message
>>> ...
>>>> "zzz" > wrote
>>>>> Urgent help needed ....
>>>>> Trans works fine in Reverse ::: stuck in 4th (drive??0 on forward ...
>>>>
>>>> It's 2nd gear, I believe.
>>>
>>> Third I think.
>>>
>>>>
>>>>> I hear it i called the lame mode...
>>>>
>>>> It's "limp-home mode"
>>>>
>>>>> Was able to drive it back into the garage ...
>>>>>
>>>>> How to I reset?
>>>>> Advise urgently needed!
>>>>
>>>> If it doesn't reset upon the restart after key being off for a
>>>> few minutes (or it immediately goes back into limp mode after
>>>> a restart), it's completely broken and you will need a rebuild
>>>> or new transmission.
>>>
>>> Depends what is wrong. Sometimes a stuck band or whatever will free off
>>> on
>>> overrun or by going into reverse and then out again.
>>>
>>> Mine very occaisionally gives this fault after long downhill runs in hot
>>> weather if I then 'feather' the accelerator (and there is a slight clunk
>>> when it gets confused about whether it is changing up or not). The rest
>>> of
>>> the time the gearbox is fine.
>>>
>>>>
>>>> FloydR
>>>>
>>
>>
>> Well, it was not "resetting" after shutting it down.
>> It is at the dealers at the moment .. should find out today.
>>
>> I shall update the newsgroup.
>>
>> Thanks to all who chimed in.
>>
>> For very selfish reasons ... I would "like to believe" it is electrical
>> and not mechanical. We shall see.
>>
>> Cheers.
>
> The verdict is in ... NOT good news
>
> 1. Appears to be a "mechanical failure not electrical" says the reputable
> local BMW dealership
>
> 2. Sealed unit ... dealer cannot repair
>
> 3. Rebuilt unit + labor =$5500 (OUCH)!
>
> 4. Towed is home to sulk over it!
>
> 5. Car has 153K miles and in overall very good condition; new tires; new
> brakes/rotors ... but $5500 ... I LOVE this car otherwise !
>
> 6. Think I can get about 4k or so on my taxes if I "donate" the car to
> charity
>
> 7. Have to pause and think my options through.
>
> 6. Any advice???
>
> Thanks in advance.
>

In article >,
KMS - Brett Anderson > wrote:
>1. Top post. Bottom posting is for idiots that can't follow a thread. Top
>posting is for people with at least half a brain that can follow a thread,
>and therefore get ****ed off at having to scroll down through a bunch of
>already read garbage to get to new info.

One could also argue that the "problem" with bottom posting you mention
is really caused by people too lazy to trim included material to the
barest minimum required to retain context. This is an age-old
problem on usenet.


--
Need Mercedes parts? http://parts.mbz.org
Richard Sexton | Mercedes stuff: http://mbz.org
1970 280SE, 72 280SE | Home pages: http://rs79.vrx.net
633CSi 250SE/C 300SD | http://aquaria.net http://killi.net

On Thu, 13 Jul 2006 23:06:38 +0000 (UTC),
(Richard Sexton) wrote:
>
>One could also argue that the "problem" with bottom posting you mention
>is really caused by people too lazy to trim included material to the
>barest minimum required to retain context. This is an age-old
>problem on usenet.

Yes, the problem is best summed up as a combination of not only top
posting, but the failure to edit for context. The latter part is the
subtle part, and the one that yer typical top poster doesn't
understand. Oh well.
--
Dan.