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Discussion Starter #1
On my 98 E300 over the last several months I have noticed the drivers window will quit working at random. When it does, the other 3 still work. When it happens I can pop fuse 16 out of the under hood box and put it back it and it works again. It started out doing this once every few weeks, then about once a week and sometimes more often. I had once instance where the key fob would not lock/unlock the car despite new batteries. When that happened I started pulling fuses for the central locking system. There are several different fuses for this which includes IIRC the same fuse 16 under the hood, and about 3 under the back seat. When I removed 16 it did not fix the central locking issue, but after removing one of the ones under the rear seat it started working again. I only had the 1 time of FOB not unlocking car. Up to this point I had been daily driving the car.

I have recently started traveling a lot for work and had the car parked at the airport for a 4 day stretch for the last 3 weeks. This includes flying out on a Monday and returning late Friday night. The first week all was fine. The 2nd week when I returned back to the car at the airport to drive home after it was sitting from Monday to Friday battery was dead. I had to get a jump and drove it home. The next day I spent time trying to see if I could find a drain. Car runs at around 13.3 volts with the battery fully charged and it running down the road. Battery is a fairly new AGM. I disconnected the battery to check for a draw with my MM and there was nothing out of the ordinary. I just figured maybe I somehow left something on while it was parked.

The very next week I was flying out again so car was at airport Monday thru Friday. Car started just fine when I returned. I then did not drive the car from Friday until Wednesday morning, so car sat for 4 days at the house and it was dead again. After I jumped it again I noticed the drivers window was not working again. One other thing I noticed is it seems the key FOB only works while standing at the drivers door now, will not work from the back of the car or the passenger side.

My working theory at this point is the drivers door module which I assume controls the drivers window is flaking out and maybe that is causing an intermittent battery drain as well since there was not an abnormally large enough draw to cause the battery to drain when I checked it, but at some point later the draw came back. I am hoping a simple drivers door module swap will cure it but after doing some reading online it appears maybe any of the modules anywhere in the car unrelated to the problem at hand could be the issue??

I need to get this figured out ASAP as I have to fly out again next week. Anybody BTDT or have any ideas or pointers on where to start or what to look for? I have SDS, will that tell me anything if I hook it up to the car?
 

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Discussion Starter #3
Thanks, I will give that a shot tomorrow. In the mean time, I have been finding a few old posts about similar problems of front windows and/or seats not working and it ended up being the RR window motor being the problem. In my case I can't say if the seats worked or not because I did not try them with the drives window quit. Also on other posts there is no mention of an intermittent battery drain. It is possible if the car was drive daily it did not sit long enough to identify if a battery drain was also going on.
 

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1998 E320 base sedan @ 160kmiles
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If a unit is not put to sleep by the controller (EIS) it will drain power. You could measure the current drain on individual fuses after 10 to 15 minutes with key out. You can also measure the total current drain from the negative battery terminal with ammeter connected in series. Make sure that all doors are closed, key out and 15 to 20 minutes passed for the system power to settle (modules going to sleep).
 

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99 E320
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I haven't read where you checked the integrity and health of the battery itself. It may display surface charge of 12-13vdc but if a cell is shorted or failed somehow, it may not store the voltage...and the electrical appliances on the car may be weak performers...or not even function. It comes down to current draw and whether your battery can provide that. It is also possible that the alternator may be overcharging your AGM battery and thus, shortening its useful life. I'm just shooting from the hip at the moment but thinking you should perform a load check on the battery (too).

I don't think you can easily perform a specific gravity check on AGM batteries so I didn't suggest that. I could be wrong
 

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Go with your dood controller theory and the stay awake. To isolate the actual culprit, you can pull the CANBUS “header” under the passenger A-pillar area, and disconnect individual units for a while. Or you could try your luck at “parts tossing” and gamble that it is the RR window motor/control unit, as it was on mine. I had the exact same airport parking experience - fully charged going in, dead as a door nail when I came back.
 

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Discussion Starter #7
If a unit is not put to sleep by the controller (EIS) it will drain power. You could measure the current drain on individual fuses after 10 to 15 minutes with key out. You can also measure the total current drain from the negative battery terminal with ammeter connected in series. Make sure that all doors are closed, key out and 15 to 20 minutes passed for the system power to settle (modules going to sleep).
When I came back from the 2nd airport trip where it was dead when I came back (it was fine after the first trip, dead on return from 2nd trip, fine again from 3rd trip, dead after sitting 4 days at the house) I measured current draw at the negative post of the battery and it was normal, no draw large enough to cause it to drain in 4 days. This was with the doors closed, key out of ignition and checked after a few minutes of sitting. I am getting ready to head out and mess with it. First thing I am going to do is hook up SDS and see if HHT turns up anything.
 

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Discussion Starter #8
I haven't read where you checked the integrity and health of the battery itself. It may display surface charge of 12-13vdc but if a cell is shorted or failed somehow, it may not store the voltage...and the electrical appliances on the car may be weak performers...or not even function. It comes down to current draw and whether your battery can provide that. It is also possible that the alternator may be overcharging your AGM battery and thus, shortening its useful life. I'm just shooting from the hip at the moment but thinking you should perform a load check on the battery (too).

I don't think you can easily perform a specific gravity check on AGM batteries so I didn't suggest that. I could be wrong
The AGM battery is fairly new, but I will load test it today. The voltage while running shows 13.3 volts on the ACC panel, so it does not appear to be overcharging.
 

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Discussion Starter #9
Go with your dood controller theory and the stay awake. To isolate the actual culprit, you can pull the CANBUS “header” under the passenger A-pillar area, and disconnect individual units for a while. Or you could try your luck at “parts tossing” and gamble that it is the RR window motor/control unit, as it was on mine. I had the exact same airport parking experience - fully charged going in, dead as a door nail when I came back.
Is this canbus headers behind the plastic panel under the dash in the footwell area, or where exactly?. Depending on if anything turns up from HHT, I may also end up swapping out the drivers door module and/or unhooking the RR window motor and see what happens. Unfortunately I do not think I will know if this fixed it unless it happens to be in the current draw mode while I am checking since it really only sits unused for a 4 day time period of I am flying out of town, in which case it is mighty inconvenient to discover the problem is not fixed with a dead battery at the airport.
 

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Discussion Starter #10
I am doing a little bit more reading thru the startek manuals and one problem I forgot about is I noticed the front dome light is not coming on when the doors are open. It comes on with the switch though. I was reminded of this because I was something about this listed in the manual somewhere and that was also tied in with the PSE module. It is amazing how modules that do not seem related at all affect other systems. In fact, I think I even saw something about the PSE having something to do with the rear window defrost.
 

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I am doing a little bit more reading thru the startek manuals and one problem I forgot about is I noticed the front dome light is not coming on when the doors are open. It comes on with the switch though. I was reminded of this because I was something about this listed in the manual somewhere and that was also tied in with the PSE module. It is amazing how modules that do not seem related at all affect other systems. In fact, I think I even saw something about the PSE having something to do with the rear window defrost.
Check all door switches. You can see switch states in PSE -> Actual values. Faulty front door switches will keep seat control modules powered up.
 

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1998 E320 base sedan @ 160kmiles
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The front dome light is controlled via the N70 (Roof Control Unit) via a command over the CAN bus from the PSE when a door is opened. The rear window defrost button and its LED are hardwired to the SAM from the a/c controller. The signaling is between the SAM and the PSE for activation / deactivation. The PSE powers the defroster wires.

When you open the driver's door, the door courtesy light should be lit, and if the door is left open for a while, the light goes off after the timeout. If this works, the door control module is able to receive messages from the PSE / SAM.
 

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Discussion Starter #14
So here is what I did today. I first did a load test of the battery which was fine. I then hooked up my C4 SDS and went into HHT. This is a 9/2018 version running win 7 and it has a separate HHTWIN emulator. In other words, like my old C3 system when you would access a system that required HHT from DAS it would launch HHT automatically. In this version I have if you access a system from DAS that requires HHT it says HHT not installed, so you then have to launch the separate program. I am contemplating ordering a new HD with the older XP version that has HHT integrated into the system. Anyway, sorry the long explanation of my current setup. I could not access any of the body modules at all from my HHT setup except for the AB module. I am not sure if this was a car issue or an issue with my HHT/C4 setup. I tried hooking up my old C3 MUX to my laptop but I guess I could not figure out how to get it to switch to the C3. I will probably try it on a different car and see if it works. I have used it plenty of times and the HHT emulator is somewhat flaky which is why I am wanting to go back to an older version for working on older cars.

Anyway, I decided that it seemed that many of the issues I am having seem tied in with the PSE so I pulled one out of a 99 E430 and put it in the 98 E300. It had a different part number but all connections were the same and I figured I would give it a shot. At first when I put it in, central locking was not working. I disconnected the battery for a minute or 2 and once I hooked it back up, now my key FOB works from anywhere around the car, dome light once again works, and it locks and unlocks.

I then unhooked the negative cable and inserted my DMM into the line to measure draw again. I had the doors closed and key out of ignition. After hitting fob button to lock the car, after pump runs it would settle down to about .49 amps. After a minute or so it would drop to .23 amps, then after a couple more minutes down to .03 amps. I waited a bit then unlocked it and it ran thru the same sort of amp drop. I ran thru several lock, then unlock cycles to see if it would get stuck and not go back to sleep after a while. I then locked the car again and left it like that to simulate how it would be sitting at the airport (locked). I went about messing with some other things and came back about half an hour later and it was showing .01 amps. I checked it several times over the next hour and it was always at .01. I am planning on leaving it set overnight with the meter on it and will check it again tomorrow and see where we are at.

I am not sure if this was the culprit or not but I figured it was a good place to start. If the problem does not occur again, I may stick this pump in another car and see if the issue follows to that car.
 

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The problem could be the PSE, or it may come back after few days. The key point is you unhooked the battery, and things started working again. It could have been the same result if you just disconnect the battery and reconnect as you did with the original PSE.

What happens is, if the CAN bus signals are marginal and cause CAN bus errors, the SAM starts keeping the track of number of CAN faults. If it exceeds a threshold, it will start taking down modules on the bus, one by one till the problem is cleared. Depending on the severity of the signaling faults, it may take days, or even weeks. When you disconnect and reconnect the battery, the fault memory in the SAM is cleared, and reconfiguration takes place.

So, hopefully the PSE replacement will solve the issue. If not, you know what to do :). This should give you some time to get the HHT-WIN work again :). I heard that the HHT-WIN does not like 64 bit Windows OS. Deplore may want to chime in to help debug this issue.
 

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Discussion Starter #16
Yea I had the same theory. I just figured with all the different symptoms and the PSE seems to be related I would start with that and see what happens. With the new PSE hooked up I am going to try HHT again tomorrow and see if it can access it. if not I am going to try it on a different car. I am planning on getting another HDD install of the older version that I can use with older cars and keep this install available to swap drives in the event I have to work on something newer.

My new C4 system is a Toughbook which I like. My old C3 system was a Dell which worked fine except the C3 seemed like it was starting to get flaky as I had been using it since around 2011 or so. The Dell laptop/install was newer than that though. Since I got the C4 the Dell just sat around and one day I decided to fire it up but for some reason the laptop is just a black screen, does not do anything. I seem to recall trying to install its drive in the Toughbook to see if it would boot and run the older install but it wouldn't boot up, if I am remembering correctly. BTW the C4 on Win 7 works fine with newer cars that do not require HHT.
 

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Discussion Starter #17
So no battery drain overnight, but only time will tell. Flying out tomorrow so car will be sitting at airport all week. Today I hooked my C4 back up with the PSE from the other car to see if it would access that module or any of the body modules. Same thing as yesterday, it would not. I then hooked it up to my 97 E300 and it accessed the PSE and most of the other body modules just fine. Some of them it kept saying turn key on even though it was on and would never proceed further. I tried it on my 99 E300 and it also would not access any of the body modules. I am betting this is more of an issue with the system rather than the car. I am going to proceed with my plan to get an older XP version to run the C4 on and see what happens.
 
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