Hello, just registered to the forum to ask some opinions about a problem in my car.

For years my car has had weird electrical symptoms like randomly alerting about "increased battery discharge", and the little green light next to light switch has been blinking. However lights are working normally and only problem worth mentioning with lights is that the left lens is always fogged up, and gathers some condensation water inside it. My last battery lasted maybe for three years only, so I think something related to that alert was ruining the battery.

Here comes the most recent episode: My car was not being used for nearly two months this winter and it was sitting outside. I was prepared for it not starting and certainly it wouldn't start, so I had to jumpstart it (under the hood) and of course the battery was dead and I replaced it right away (with coding). Then the car would try to start very well, but didn't start, so I took it to a nearby repair shop where they changed glow plugs and glow module. After that it was running like it was new for a few weeks, and then again today I got the battery discharge alert. I really started looking into that problem and noticed that my car is not going to sleep mode at all. The small orange "P" light next to the shift lever stays illuminated constantly no matter how many hours my car sits unused. Then I hopped into my car, locked the doors and made sure, I didn't touch any buttons or door handles for like 20 minutes. What I have understood, after 16 minutes since "last activity" the orange P light should shut down, but that didn't happen this time either. What happened, was that right around that 15-16 minute mark I heard some knocking sound (maybe from the engine?) and also the small speakers in the front doors made a very faint popping sound and started creating very faint static sound that i could barely hear. I also think i heard the fuel pump starting (as it does when you are about to start your car).

My car has been always running well with no real issues, but has been doing a lot of weird stuff for a long time. Such as losing time and date, and changing languages in the iDrive display overnight by itself. Also when I start my car, Check control says that my lights are not working, but they really are working.
I would really appreciate some advice where to start looking for a solution, and I would like to start doing it by my self, because it is quite old car, with over 450 000km with it, so I wouldn't want to pay a fortune for a troubleshooting at a repair shop (at least at the beginning).

 

I hope I cover everything in this post but if I don't let me know what I forgot and I'll respond.

1. Were you sitting in the car waiting for the car to go to sleep if so then that's not going to work. You need to be out of the car.

2. Your battery is draining due to a module not going to sleep. I would perform a parasitic drain test starting with the well known modules that go bad (TCU, MPM, DME, etc). You may want to start by physically looking at the modules in the spare tire area. Those are known to go bad especially the MPM.

3. Your light is flashing green because you have an error in the system. I'm sure the adaptive part of your light system is not working correctly. You need to change the SCM under the headlights and the ALC under the glove compartment. At least that's the route I would take since they are cheap. I would start with replacing the SCMs under the lights first as they are known to go out due to water damage after 10 years. It's an easy DIY but they do need to be coded afterwards.

I believe I covered everything.

 

+1, and you need to read your DTC codes..

 

Ok, thanks! It seems a nightmare to exactly pinpoint the real cause for that alert. Yes, I was sitting in the car during my "experiment". I will repeat it today without being inside the car. I also checked the MPM module under the spare tire, which looked good and there was no water present in that area. By the way, If I want to use multimeter to measure the parasitic draw from the battery, how can I do that with the trunk open? Can I somehow trick the car to think that the trunk is closed?

 

Trunk and passenger door open to test the2 fuse boxes. Wait until car goes to sleep then run the test. Remember if you open up a door while performing the test you'd have to wait until the car sleeps again or you'll get false readings. If you don't find the problem in those 2 locations then you'd have to open the hood to check the fuse box.

 

I run the multimeter leads outside of the trunk and close it. The trunk seal won't damage the leads.

 

I just watched a good video from youtube, how to pinpoint fuses where current runs through during sleep mode with multimeter, and i would like to try it. However the car doesn't go to sleep mode at all, so is there a way to make it go into sleep mode without ISTA program's "Forced deep sleep mode". Or should I just let it be "awake" and try the same thing and see which fuses are alive? And second question: Let's say i leave trunk and doors open, but lock the door locks manually, pressing the metal lock hooks in locked position, will the car think it is closed and will go to sleep as much as possible, and then i can test fuses that are drawing current during that? Maybe a confusing question, but I would like to do this without having to get ISTA for now.

This is the video I am talking about.

Thanks in advance!

 

I don't know if you didn't understand what a wrote previously or I wasn't clear. What I described was you doing a parasitic drain test then you said you watched a video of the same thing I was telling you to do. Perform the steps I explained. Let the car sit for 30 mins and start testing. If a module is preventing the car from sleeping of course it's not going to go completely to sleep. Open what you need opened and let the car sit. Then perform the test. Did I mention to let the car sit for 30 mins with the trunk and passenger door open then start the parasitic test that I mentioned and you saw a video on how to do it. Oh and don't forget not to open or close any doors while you're doing the test. I think I've covered how to perform the test in detail along with the video you watched.

 

I forgot to add once you find the fuse/s that still is running high power record what it controls and pull the fuse. If the car doesn't go to sleep then keep going until it does and once the car sleeps you've e found you module/s that has the issue and you troubleshoot from there. It could be the module or a part controlled by the module. You have isolated the issue

 

Ok! I will try that today. Reason why I was confused was, because I wasn't sure if this test is valid when the car is not forced to sleep without ISTA and it could mess with the results, because in the video, the guy first forces the car to sleep and then starts measuring. I think that is just a way to save time to get it sleep as much as possible fast.