check control module - advanced course

[lesage]

I think the bbq is a great idea. maybe one for the northern hemisphre and one for the southern one :-)

[Ladykats]

Hello gentlemen,
I am hoping that one of you can assist me. I have a 95 525i that is doing exactly what you descripted in giving read out of oil level low, and coolant low. After reading this thread, I swapped the CCM from my 94 740il into my 95 525i. I still have the same readouts on the dash display. Is there any thing else that could be causing reading besides the sensors. Out of my 5 BMW's this is the only one with display problems. A friend has a spare coolant level switch for this series bimmer, which he is bringing in tomorrow. I am hopeful that will be the fix for that display. But one never knows.

Ladykats

[Javier]

the same warnings, you either have a real issue as reported, a bad sensor, or a wiring problem between the sensor and the CCM. Opening coolant level circuit will produce a warning signal, so broken wire or dirty contact will result in an event report. If you pull out the sensor connector, jump with a wire the two contacts, and signal disapears, the sensor is in trouble.

Low oil is more complicated, but may behave similary in an specific open wire/dirty contact condition. (dual contact, one opens, one closes to ground)

Javier

[lesage]

I final comment: the current drain was tracked down to the CCM and only the CCM. Replacing it with a known good one reduced the drain from .19a to .04a

My thanks to Shogun for the original posting about CCMs, and the suggestion to visit the e32 board. And thanks to Polcon (Nat) on the e32 board for volunteering a spare CCM to try out.

Incidentally, a rogue warning about Licence plate lamp not working which iI used to get still continues with the new CCM...so that aspect hasnt changed...

Javiers comments about the board and its value- human and parctical, - is endorsed.

[Javier]

checking the hinge harnes at the trunk lid. Think it will be my first advise for any electrical issue related to trunk lid devices.

Javier

[lesage]

Javier: Light bulbs are fine (BMW supplied so wattage s/b OK). The PO had had BMW replace the rear harness under warranty as I understand. Doesnt mean a fault hasnt reappeared of course & would agree harness a likely cause. However the Check Control error message varies as to the time it appears. Sometimes as soon as lights are switched on (esp with this 'new' CCM); sometimes only after a while. So It might I think also be an LKM imperfection

[Dan in NZ]

Dirty contacts on the bulb holders? Leaking lamp housing?

I had an intermittant "tail lamp" warning for a week after using a high-pressure car wash. Must've got a bit wet and taken a week to dry out...

[lesage]

[QUOTE=Dan in NZ]Dirty contacts on the bulb holders? Leaking lamp housing?
True: I should check those more carefully. I havent cleaned the contacts with an abrasive. One reason was that I couldnt work out how to detach the lamp fitting from the loom. While the connectore has the appearence of a straight forward slide in and push fitting, I couldnt work out how to open it. didnt fancy a pile of work in wrenching it open, replacing etc...