door locks/interior lights/sunroof/windows inop

[duckloads]

I'm having a bit of problem when the ambient temperature reaches the mid 30's and lower. My door locks/interior lights/sunroof/windows become inoperative.

I have cleaned the battery terminals and removed and cleaned the fuse link strip under the plastic housing mounted near the battery.

Any Ideas would be appreciated.

The car is a 1991 535i.

Thanks,
Chris

[Javier]

then the issue comes from GM/RM modules. Check good connection in their sockets for: Fuses F17, F24, F30, F47, Relay K15, and modules GM and RM. This picture will help you identify some of the items below the rear seat.

http://www.bimmernut.com/~billr/images/rear%20fuses.jpg

I would plug/unplug the relay K15 (Power Protection), as if he is not activating properly (you should feel the click when plugging in if key is in running position), power is not reaching windows/locks.

The issue may be as simple as a damaged/overheated fuse socket or fuse that disconnects under freezing cold. You can help yourself identifying the culprit with an hair dryer, point to specific items, and see if warming them solves the situation.

Note: Battery should be disconnected to plug back the GM.

Javier

[duckloads]

Yep also the wipers only work on high. Thanks for the tips. Perhaps in the morning (in the 20's) I'll be able to check it out .

Thanks agian,
Chris

[Javier]

be as simple as a broken fuse filament, that shrinks under cold and disconnect power to control circuits in GM.

Javier

[duckloads]

can a single fuse cause all these malfunctions?

[Javier]

for operating windows, locks, Wipers special functions (High speed is keept appart for safety), and Automatic interior lights.

This is achieved trough the RM (Relay module). If for example you loose F30 that powers the coils to the relays in RM, and some functions in GM, you will loose all GM operations.

Javier

[duckloads]

Javier,

I finally got around to testing the circuits in my car causing me cold weather problems. It is in the upper 20's here in Huntsville, AL this morning, and all of my window/wiper/lock/sunroof/etc. are non-functioning.

thanks for the procedure you posted on 11/6/05 fo drmmaster. I went throught the ground and voltage checks and everything checked out OK. I have good grounds and 12.9vdc power where it is supposed to be.

I opened the GM to look inside. I saw a bunch of little crap! That's technical talk for a mechanical engineer looking at a circuit board. I put it all back together (GM & LM) hooked up neg battery, and everything came back to life.

Where do I go now to determine if infact the GM is "bad" during cold weather?.

Thanks a bunch.

Chris

[gruffalo]

hi,

I have the exact same problems. I have voltage everywhere, but the GM shuts the PPRelay off. So I guess it's either GM failure or a reason for the decision to shut the relay off.

What causes the GM (assuming it is OK) to kill the PPR?

MM

1990 525iA m50

[duckloads]

I don't know if the gm shuts the ppr off or if its the other way around. Here are some tests to determine if your ppr is bad. Relays do sometimes go bad.

If I warm my GM up with a hairdryer then everything works again.

[Javier]

Inside the GM, there is a series resistor, which measures the total current flowing to most devices controlled by GM. Whenever this resistor exceeds a pre-set voltage (which means current trough it exceeded a preset value), the GM cut power to the PP Relay coil. If the resistor is damaged, or excessive cold shrink its leads, causing them to increase connecting resistance in the soldered joints to the PC board, then total resistance is greater and under low current can trigger the PP relay.

I would check carefully the GM PC board looking for trouble in that resistor. Check this link for further info. This of course, if PP is dropping or not engaging at all, being it in good shape. Note that if resistor is opened, no mater the PP relay status there is no power flowing into the GM controlled devices.

http://www.bimmer.info/forum/showthread.php?t=9950

Javier

[duckloads]

I'm not sure what resistor you are talking about.

[Javier]

the terminals corresponding to pins 4 and 5 going to X332 connector (the power one, with only 5 pins, where the GM plugs in (see link posted before).

If you follow the paths in the board from pin 4 to pin 5 you will go over the mentioned resistor. Also if you pull out the GM and measure resistance between those pins, and notice a difference if cold or hot, you would have found the problem.

Javier

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Thank you very much

[gruffalo]

guys, I found the problem today, the wires running to the trunk lid were damaged from 15 years of bending, and once I fixed that, everything is OK.

mm

[Javier]

almost every gremlin on this car.

Javier

[duckloads]

I'm glad the other guy found his problem, now back to my thread.

I get no difference in resistance between pins 4 & 5 weather in freezer for an hour or at room (70 deg f) temperature. Both values are as close to zero as I can measure.

[Javier]

0.3 is ten times 0.03. Do another test, verify Fuse F47 is OK and not overfused, should be 30A. Remove the power protection relay and jump (connect with a short wire) its socket from pin 6 to pin 2. Should be the holes corresponding to relay pins 30 and 87. This will bypass power protection.

Test the module but do not top the windows, you may want to put GM in the freezer for some time and also test it is not working before removing the relay and jumping its socket pins.

If every thing work fine, then you have an issue in the PP relay itself, or in the pin 4 to pin 5 in GM current metering circuit (or relay driving output transistor at pin 10 of connector X253 (http://www.bimmer.info/forum/attachment.php?attachmentid=692&stc=1&d=1134863887)). If not working, then something else is wrong inside GM, look for a magnifying glass and check all the solder joints.

Javier

[duckloads]

Thanks for the additional tests. I'll do this test first thing in the morning, when problem exists on its own due to cold. I warmed it up a few minutes ago in the house to get things working again. I'll let it die again naturally overnight.

Thanks for sharing your knowledge.

[duckloads]

Javier,

I conducted tests as described. Checkd fuse, jumped pins 2&6 on relay, etc.

The interior lights and wiper function was RESTORED. I didn't check windows or sunroof. I swapped PP relay with the "other" orange one. All pertinant functions still dead. It is not the relay.

So it seems I have trouble in the GM between pins 4 & 5 or at pin 10 of the connectors you described above.

I'll resolder joints in these areas of the GM.

Got to go to Church first

Good day

[duckloads]

Last night a friend of mine that was an electronics tech at Chrysler for 20+ years re-soldered parts of my GM under a magnifying glass. He re-soldered all the pins to connector 253 and everything to do with pin 10. He resoldered everything he could see pertaining to pins 4 & 5 and everything pertaining to that connector also.

All functions worked when I reinstalled the GM.

This morning is nice an frosty, And ALL THE FUCTIONS ARE DEAD as usuall.

Perhaps I have a component inside the GM going dead?

[Bill R.]

. If not it can cause many problems with the gm.




Last night a friend of mine that was an electronics tech at Chrysler for 20+ years re-soldered parts of my GM under a magnifying glass. He re-soldered all the pins to connector 253 and everything to do with pin 10. He resoldered everything he could see pertaining to pins 4 & 5 and everything pertaining to that connector also.

All functions worked when I reinstalled the GM.

This morning is nice an frosty, And ALL THE FUCTIONS ARE DEAD as usuall.

Perhaps I have a component inside the GM going dead?

[duckloads]

Yes. Thanks

When I warm it up with a hairdryer, everything works again.

[Javier]

component inside the GM. Hard to decide what to do from now on, as it will depend on your electronic skills. The basis of the circuit that seems to be compromised, is very simple, it monitors current from 4 to 5 and if low, grounds pin 10 to energize PP relay.

May be your friend can debug the GM and fix it for you.

An alternative is to find a replecement GM on ebay. But before doing that, I would swap (if possible) with a known good GM with a friend to be absolutelly sure there is no shortcircuit causing this issue.

Javier

[duckloads]

I'll write the final chapter in this saga, so that future generations may learn from our adventures.

I took the GM board out of its case and re-installed the board in its sockets. I bought a can of freeze spray from the local electronic supply store. I used a hairdryer to warm up the board, so that all the functions worked. I hosed down the board with the freeze spray, and all functions quit working. I warmed the board back up, and sprayed down a smaller area. I then warmed it back up.

I continued this process for at least 30 minuets freezing a smaller area each time.

I narrowed down the problem to a "thing" on the board and NOT a solder joint. I took the board back to the Electronics store, and told the guy I needed one of "these". He said Oh! You need a 47 mirofahrad 24 volt capacitor. (or something like that)

I bought two of "them" for $0.80, and took them to my electronics tech friend. He removed the old ones and soldered the new oned in place.

Well the car spent all night in the low 20's, and this morning ALL OF THE GM MODULE FUNCTIONS STILL WORK!!!!!

Holy cow I think we fixed something instead of replacing it!!!!

I have a photo of the new capacitors (2) in place, but I cann't figure out how to paste the pic.

Good day, and thank you

[Javier]

Javier

[gruffalo]

Anybody still remember this thread? Well guess what, I'ts cold outside, and my GM has decided to shut off the PPR.....

Off to find the hair dryer...