It’s very possible, that after several blog entries (here and here), where I described, how important is the registration of battery replacement (and very important – correct registration, not, for example, using tools, made by the third side) and timely replacement of the battery, many of you would think – this person exaggerates. Say, nothing happened to my car, my friend also replaced the battery without registration – also for him everything was OK.
Possibly, this entry will change your mind.
At first, you have to understand, that, for example, to start the vehicle who is in technical order during summer, is enough just some % of battery capacity. Also, start current can be much lower than indicated on the battery body. In wintertime, these requirements grow, but even in very cold weather, if the car starts by the first or second try, it will be enough with a small amount of full battery capacity. A true test for battery starts, when in wintertime the car doesn’t start with third, fourth, fifth time. Or – the car has been left for a longer time in non-sleeping condition. Of course, everything is relative, and I can not strictly say, that, for example, “by -20 oC the battery can be able to start the car 10 times without any signs of weakness”, but with this I wanted to say – we (car users) actually don’t know the true condition of the battery. About its insufficient performance, we find out when the car doesn’t start anymore. Most part of BMW users are driving cars, the performance of who’s battery is much worse as it’s supposed to be, but – nothing gives a sign of it.
And now, it’s time for today’s problem situation. E90, N43 series engine, model of the Year 2009. Several months ago, the basic problems were solved: CCV system was put in order, also NOXEM was installed. All parameters looked correct. When more cold weather came, the owner of the car started to complain, that cold engine, directly after starting, shivers strongly. First thought – leaking injector?
Today I connected INPA. Outside temperature -3 oC. The car has been staying outside for more than 12 hours. Before starting I checked the rail pressure. Both: low-pressure and rail pressures were around 4000 hPa. It looks that no injector (in a closed condition) is leaking. Two error messages recorded in the DME error message memory list:
- oil pressure (static) – problem, which mechanic plan to investigate in nearest future. The error message has been recorded for around 70 times after last deleting of the error messages;
- the error message regarding IBS. Status: passive. Recorded around 1k km before, just one time.
Both error messages were discarded as not possible causes of strong (and repeatedly) shivering.
I started the engine – the engine started very evenly. Low-pressure: correct. Rail pressure: normal (around 150.000 hPa). After several seconds DME starts to warm up wideband probes, they indicated Lambda 1.00 in both banks, integrators – correct. Has the defect really disappeared?
Suddenly the engine shivered strongly. RPM dropped to 300 .. 400. Interior lightning became significantly dull, after a second the engine started to recover very reluctantly. For around 10 next seconds – the engine performed perfectly. And then – again “pause” of one second. The engine continued to shiver in such manner after around every 10 seconds.
Additionally, no error messages were recorded in the DME error message memory, not even taking in account EML symbol, which lighted up time by time.
Symptoms, which I noticed in the moment of shivering:
- low-pressure and rail pressure disappear – they drop swiftly, after problem – are restoring;
- Lambda in both banks directly after shivering – increased: around 1.3 .. 1.5 (the mixture is lean – not enough fuel);
- onboard voltage drops swiftly, but in the pauses of problems the alternator maintains a voltage of around 14.4 V, no error messages regarding the performance of the generator are present.
The direction of the problem was indicated by Info list: ../F4/F2/F1
Note: INPA is only diagnostics tool, who “see’s” error messages of Info list.
Hot restart of DME? Such a situation can happen to MSD series DME. Rare, in addition – usually this problem is much less pronounced – during around half of the second DME restarts, and – the problem doesn’t repeat for a long time. During several hundreds of thousands of km, I have experienced only several times, when DME of my car restarted in such a way.
Note: the picture of the error message was taken later, after eliminating the problem, for this reason its status is passive. During the problematic session, it was active, odometer indications confirmed recording an exact moment.
But in this case – restarts last much longer, electricity almost disappears – obviously: the alternator is disconnected via BSD, fuel pressure disappears – EKP disconnects low-pressure fuel pump (but under-voltage errors of EKP are not recorded, obviously – it’s deliberately disconnected for short moment via management interface).
Here, this error message is registered for 16 times. Unfortunately, the attributes don’t give more detailed information, what has happened. SPI (Serial Peripheral Interface) in MSD is used for communication of peripheral units (memory chipsets, ADC etc.).What does status 16 means, only developers of DME know.
Damaged DME? Some of the chipsets send faulty data? The contact of PCB is disappearing?
All these defects are possible, but I decided to check IBS data. I had reasons to be suspicious about IBS, because:
- just only one time, but still the error message regarding IBS sensor was recorded;
- in the moment of the problem the alternator was disconnected;
- in the moment of start I had a subjective feeling, that that battery is not in a good condition.
All these symptoms are telling me – one of the IBS procedures has been performed incorrectly.
Here, data of IBS system:
Do you see something suspicious?
Here, I marked incorrect data:
As you see, SOH has reached negative (incorrect) value, data of energetical balance of last days – completely illogical and unreal. Charging data of actual day – incorrect (IBS tries to maintain SOC in range of 60 .. 80%, additionally – the car was staying in lowered/cold temperature – charge in no way could be 99 %).
Additionally – as we see, not looking at the solitary age of the car (10 years), the battery has never been replaced. The vehicle is equipped with a Start-Stop system, such long work-life of initial battery don’t sound real.
Note: negative SOH value can be reached if the existing (actual) battery for an inappropriately long time hasn’t been replaced with a new one (or, more precisely – IBS systems “thinks” so, because it’s not informed about the replacement of the battery). Exactly the time (aging) component of the IBS system is one to blame in such situation, why even new battery is considered as hopelessly damaged, not looking at the perfect technical parameters.
Data of energetic balance, which you see in this menu – obviously, the counters are overfilled, went to “second circle”.
Owner of the car claimed, that during few last years the battery hasn’t been replaced. Taking in account, that the battery hasn’t been charged correctly for a long time (accordingly – weared much faster than it would happen, if it would be served correctly), a decision was made to replace the battery and register it correctly.
After removing the old battery
we have to state several interesting nuances:
- this is not a cheap aftermarket, but BMW OEM battery;
- the battery has been manufactured on the Year 2013, so for sure it’s not the first battery of this car.
It’s obvious, that the owner of the car was not tried to save money! But, obviously, specialists, who replaced the battery, knew nothing about a necessity to register it!
The new battery was registered with ISTA D.
Attention – for registration of the batter using only ISTA D/+/P! Even INPA tends to register the battery incorrectly, not even talking about software of other developers.
Confirmation for successful registration of the battery.
After registration, I performed check-up of IBS parameters, using INPA.
Here – INPA also confirms, that the battery has been registered. But, what is much more important: all data of energetical management of previous battery are being deleted.
Here, also SOH data, counters of battery performance tests are being deleted. IBS management has started a new life!
Cold start tests on the next day after replacing and registering the battery indicated – shivering of the engine and disrupted charging have disappeared.
Yes, of course – this is one of the software bugs. Unfortunately, nobody will fix it, because the model of this car is no longer on production.
I’m more confused by another topic. BMW has created a truly advanced IBS system. At the same time – with ISTA tool (which is available in dealer services) there is practically no access to hidden data of this system. Accordingly – there is no possibility to correctly diagnose the problem. Even more – in case of wear of the battery (incomprehension of IBS) – no error messages at all! If there would be some, the batteries would be registered after replacement – many problems (also hidden and as if not connected to IBS defects) would be avoided.
And finally – unfortunately, the dealer center would not be able to identify this problem, because INPA is prohibited there. Instead, ISTA D “don’t see’s” not the Info list of the error messages, not the energetical balance of the battery and other hidden data. Most probably, the dealer would order to replace DME. After replacing DME the problem would disappear because IBS registers of new DME would be cleaned (correct). Yes, the problem would be eliminated for some time (till IBS would notice, that SOH of the battery is low), EUR 1500 would be spent unnecessary, and after a certain time – the problem with the performance of the battery would restore.