Technical 4x4 AWD not available / What might be the cause?

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Technical 4x4 AWD not available / What might be the cause?

btw I did disable the start/stop about three years ago because my daughter got her licence and she did not manage to realize when the car will restart autmatically after being choked off ...

And since then it was not reenabled ;-)

So the battery should be not really under stress.
 
btw I did disable the start/stop about three years ago because my daughter got her licence and she did not manage to realize when the car will restart autmatically after being choked off ...

And since then it was not reenabled ;-)

So the battery should be not really under stress.
Good idea well done.
How did you disable the stop start system?
 
Hi,

can anybody help me out with a list of the fuses in the central fuse and relay box? In my owners manual they are only partially listed :-(

Thx,
David
 
Hi,

Concerning the zero point somewhat low voltage reading from the Body Control Modul (Delphi) I found some other posts in the internet classifing this as a bug in the Delphi BCM.

Thx,
David
 
Hi,

Concerning the zero point somewhat low voltage reading from the Body Control Modul (Delphi) I found some other posts in the internet classifing this as a bug in the Delphi BCM.

Thx,
David
Thank you for posting that info, I was wondering about bcm strange voltage report.
Jack
 
Hi,

let's try and resume what we have so far.

On restriction is, that my multimeter is a 5 Euro device - it reads systematically to low. I hope we can interpret the data anyhow.

First abstract the system as Supply-Side and Load-Side.

In the Battery Test <BatterieTest.png> the Load was high (starter) and the alternator did deliver. Thus we can suppose that the Ri (inner resistance) of the alternator is to be neglected. Supply side is ok. We can confirm this when I have a look at the Coupling Control Module and the cc solenoid valve. When I manually engage the valve from the Multiecuscan, the voltage as seen from the CCM takes a drop from 12.315V (cf. <off.png>) to 12.189V (cf. <on.png>) while the reading on the battery pole (supply side) stays virtually unchanged (lacking somewhat behind, which physically is impossible, I attribute this to my high-end-measuring-equipment, that gives a somewhat to low reading). Thus there is all the work done on the load side, none on the supply side. That's the way it is supposed to be.

(NOTE: Voltages are low as I am working on a 82% loaded battery. Manual actuation is not available while the enginge is running, so I had to do this test battery backed. Don't let this trouble your sight for the underlying pattern!)

From this test <off.png> to <on.png> we can further deduce that there is a remarkable resistance in row to the payload (consisting of the CCM and the solenoid being in parallel). This is not the way it should be.

Same picture I get when I go through similar test for the ABS Controller and the corresponding 8 plus 4 valves and the pump. Repeatable net voltage drops around 0.15 to 0.25V per device.

Now imagine in the case of the 4x4 jumping in (1 solenoid), the ESC jumping in (quite a view of the 12 valves plus the pump) then the there will be some rise in current, hence this not negliable resistence in row will take a big part of the voltage.

Ah, yeah, and as we observe this pattern for several Control Units, it should be somewhere very early or very late in the wiring going up to the or coming from the supply side.

Besides that I was taking a motorway ride to confirm that the recharging voltage really goes up to (and somewhat above) the normal 14.4V. My max was 14.6V.

And something measurable which I could not capture is, that when engaging the coupling control solenoid, the voltage reading drops shortly to 11 and somewhat.

I managed to capture this effect only when driving. It is a curve and I really did hit the throttle. Here you see a voltage drop to 11.87V recorded. Given the fact, that it is a digitalized reading, the "real" minimum should even have been somewhat lower. Now imagine the ESC jumping in at that very moment, starting the ABS pump and engaging up to 2 release and 2 load valves simultaneously...

My opinion (I challenge you to put me wrong!) is, that:
1. Charge Control (the device on the negative pole) is to defensive, hence we only obtain a 82% load state. As the whole supply is really at its limits by design (remember, they where fored to withdrew even some early available configurations like "winter package" with "additional e-heating"), this leads to faults in heavy use situations.
2. There is a unwanted resistor in row, probably a bad ground connection. Any garagist should be able to easily identifie the root cause of this.

Thx for your contributions!

David
 

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I think I follow what you say.

The 82% full battery reading may not be accurate if you are reading from ecu in car.

On other vehicle makes when new battery fitted you have to program ecu that new battery fitted, otherwise the ecu will not change smart charging algorithm suitable for old battery to new battery algorithm. So your new battery may not be getting fully charged.
intelligent battery sensor on battery negative lead could be causing a low charge state too.

Checking battery ground lead/s and connections and battery positive lead a very good next move. I think there could be high resistance somewhere.

Together with a present to yourself of a slightly better volt meter(-:
 
Supposedly the act of powering down and reconnecting the battery negative lead is enough for the system to update elecrical parameters.. ( common fix for no stop.start) ;)

My cheap Ebay meters always work ok for a few months.. one I use now says 15v for a charged battery.. and indicated 12.6 will not get past shuddering dash equipment :eek:
 
Supposedly the act of powering down and reconnecting the battery negative lead is enough for the system to update elecrical parameters.. ( common fix for no stop.start) ;)

My cheap Ebay meters always work ok for a few months.. one I use now says 15v for a charged battery.. and indicated 12.6 will not get past shuddering dash equipment :eek:
That would be good but I'm sceptical .
Other makes require updating ecu responsible for smart charging system when new battery fitted. If its not updated the new battery is not charged as fully as it could be.


The IBS frankly gives me IBS !

Bmw have problems with IBS and smart charging. One function of system is to shut down systems so battery retains enough stored power to start car, a number of people have found they haven't been able to start their bmw until IBS disconnected. So the IBS meant to enable a start on a low battery prevents that start!!
 
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Hi,

I am going to quote from the highly recommended "Manuale di elettronica Fiat Panda, 0.9 Twinair... EAV99 - Autronica S.r.l."
<<
Ricalibrazione del sensore
La ricalibrazione si attiva automaticamente quando il sensore viene collegato alla batteria (sostituzione). Ne riconosce il tipo ed il suo stato. Durante questa fase le tolleranze sono maggiori.

La ricalibrazione termina quando il sensore riconosce le normali condizioni di lavoro e dopo un periodo di riposo di almeno 4 ore seguito da un avviamento.
>>
This basicaly means, that everything goes automatically.

Does anybody have an idea where to buy this "sensore di stato di carica". This is basically the sensor for the Delphi-Software which in turn will control the induction voltage on the alternator - correct me if I am wrong on this one.

Can anybody explain me roughly or name a resource where to learn about the trick / inner workings of this sensor on the negative pole. How does it detect the batterie state by observing the negative pole?



HTH,
David
 
It basically magic !

A super micro chip runs some algorithms that whispers a spell to another micro chip in a hidden ecu that makes a spell to cause the generator to make electricity.
Stupidly over complicated in my opinion but I realise I value reliability.

Less complex than bmw where you have to register new battery in ecu , thank you for that information (-:
 
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sensore di stato di carica della batteria
Is the intelligent battery sensor.

I wonder if you disconnect the lin bus connector(The small plug with thin wires) from the IBS if the delphi charge controller ecu will run the alternator like a tradition alternator. Regulating the voltage around 14.4 volts. Perhaps you could try this and report result?
 
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... I wonder if you disconnect the lin bus connector(The small plug with thin wires) from the IBS if the delphi charge controller ecu will run the alternator like a tradition alternator. Regulating the voltage around 14.4 volts...
Divine inspiration! Great, gave it a try and had a ride with the connector unpluged.
14.1V constant. Even when heavily accelerating in a narrow curve no voltage dip experienced by the ABS.

As the eating is the proof of the pudding, I am impatient to go to the mountains and see wether the 4x4-capability is back in this mode.

Basically this would not eliminate the root cause - as we see from the 14.1V reading of the ABS there is a resistance in row. Probably a bad ground connection...

But this will be easily found and eliminated!

Stay tuned ...

Thx,
David
 
Hello,

Me again. Been in the mountains. Did a trip on the road without the battery management and logged the CCM. When the Coupling Solenoid jumps in, the Voltage takes a dip of about half a Volt (14.1 => 13.4).

Offroad no avail. 4x4 not available.

Have to identify the "parasit" resistance / load in row with my payload (valves and pump).

To go ahead: Can anyone advice me on how to measure the voltage drop on the ABS Acu?

I know the connector. It would be easy to measure the resistance between the + and the ground.

Given that there is a 40Amp fuse and taking the 12V into account, the possible values for the resistance will range from "near nothing" over "nothing" to "absolutely nothing". Hence I would like (which always is prefrerable anyway) to observe the voltage in vivio.

Connector connected will pose me some problems concerning accesability of the pins. How do the pros do this kind of "electric" measuring?

The "electronic" reading of the controller is hard to interpret, as it has no "common denominator" with what I can read on my (or any) voltmeter.

:-(

Any ideas welcome!

Thx,
David
 
Hello,
...
It would be easy to measure the resistance between the + and the ground.
...
This should read "It would be easy to measure the resistance between the - pin and the ground."

Sorry for the confusion

Thx,
David
 
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