donjegge

I've never posted before because I like to research the existing info before asking for help, but in this case Im lost. 2002 c5 - this winter some snow got into the car and it was quite damp (as in fog in the windows.) The battery would go dead in 2 days. The short would draw .9 amps. Pulled scm L fuse and draw went to .4 amps. Pulled 25 fuse and draw drops to .01 amps. Now, I pulled fuse 23 and 25 and measured IPC draw at zero so I dont think its IPC. Some have mentioned the lumbar and motors are a common weakness when fuse 4 and 25 are involved. Is it as simple as disconnecting the wires to the motors and seeing if the amps drop? Any clarifications would be appreciated. I've already scoped out the scm module and relays and seat switches and found no shorts.

old stingray

Just unplug the seats and check the amp draw.

donjegge

thanks old stingray! Sometimes cant see the forest.....

The amp draw drops from .9 amp to .4 when the seat is removed (both plugs), so I guess I can assume it is not solely in the seat.

dadaroo

Not at home so I can't comment fully now.

After you measure the total drain, one thing I recommend is to start by disconnecting the feed to the I/P fuse box. That can tell you how much is from the engine fuse box versus the I/P fuse box.

It is a large red wire to the rear and passenger side of the engine fuse box. It is landed on a stud there.

donjegge

dadaroo, i will but could not today due to rain. I thought i was doing this when i pulled fuse 25 and 23 and disconnected all 3 bcm plugs, hence isolating the ipc and it was zero. i guess this will confirm that diagnosis,

dadaroo

Does any of this help?

BCM +12V power feeds from I/P fuse box:

Fuse #25 = BCM Logic Power Feed (Powered all the time)
Fuse #23 +Power feed for 12V BCM Drive outputs (CL)
Fuse #13 = 12V switched from ignition switch (ON, and START positions)
Fuse #9 = 12V from Ignition switch (ON and ACC position)

BCM grounds:

A9-C1 connector pin Logic Ground
A2-C3 Power Drive Ground
G104 & G202

PCM +12V power feeds from underhood fuse box:

Fuse #23
Fuse #16

Ground is G106

IPC +12V power feeds from I/P fuse box:

Fuse #19 (only powered when ignition is ON)
Fuse #25 (powered all the time)

Grounds are G205, G104, G201

donjegge

Thanks dadaroo, i will digest this and try to put together a plan.

I read here that pulling fuse 25 and 23, with the battery connected, keeping the ignition off, disconnecting the 3 plugs going to the bcm and measuring the draw across fuse 25 would tell me if the ICP was drawing any current, essentially the ICP would be isolated with those conditions. I will do it the way you suggest just to make sure.

dadaroo

If you can't find your issue then maybe we should discuss on the phone. You are welcome to PM me with your phone number. I prefer talking over typing.

PS: Your logic on the IPC and current draw seems sound. Will review later when I am not drinking beer. I have also seen where a bad BCM comes out of sleep mode and starts actuating things and draws the battery down with no/little evidence left behind. It took 2 weeks until we caught it in action.

donjegge

Dadaroo, I just wanted to close the loop on this thread, and for anyone else who might read it. I appreciated your offer to help but i realized I was in over my head, and would be wasting your time. A capable friend "supercraig" found and fixed the following. The lumbar pump was/is in fact failing, but that was not all of the issue. The failure had caused a relay on the fuse panel to stay on, and was noticed by being hot to the touch. Once the lumbar pump was unplugged and the relay replaced amp draw dropped to .04 and was fine. I guess the relay was not allowing the bcm to sleep. Now i just need to replace the pump motor, and I should be good to go. Thank you for your help.

Bill Curlee

The designed Sleep Current Draw is 20-25 milliamps. If you remove the fuses to the BCM, The BCM can not function and put the car into sleep/security mode.

Your current draw is still a little high but will not cause a one night battery kill.

Are you sure the BCM and the area around the BCM is not wet/damp/

If the BCM was wetted , it coiuld have white corrosion deposits on the circuit board:



Bill

Bill Curlee

Like the corrosion on the BCM board see here:

donjegge

Thank you Bill, I will pull and check it out.

Bill Curlee

Becareful

The card is ESD Sensitive!!!!!!!!!!! Make sure you disconnect the battery before you mess wityh the BCM.

If you find CRUD,, Alcohol and a soft nylon bristle brush will do the trick... Take pictures!!

dadaroo

Thanks for the update. Anytime I can help just let me know.

Follow what Bill says and be careful in handling the board. Make sure you don't have any static charge on you/hands before you handle it and you will be fine. Don't be scared to do it.

donjegge

oh this is such a joy..... a gift that just keeps giving...

Bill and Dadaroo, the amp drain was only .004 not point .04 as stated, so it looked good. We left the lumbar pump disconnected and buttoned it up. Took it for a ride and all was perfect.

Until....

Dash lights out. Abs light on. Gages like fuel and oil pressure 0, and temp maxed. radio and temp control unit black. Traction control warnings, reduced power notification. serv eng soon, check tps.

In other words all hell broke lose.

Battery is fully charged.
Disassembled the BCM and no issues with corrosion.
We did the ignition key de-carbonizing thing by unplugging the battery and turning the ignition key 200 times.

When we wiggle the connectors into bcm these symptoms change and some things work while other things stop working.

We have checked all ground points and connectors for corrosion.
We have pinned out and checked continuity on the plugs going into the bcm. We disconnected the seat to double for check SCM induced issues. We checked for full voltage on eng fuse 19 inj fuse 18 and tps 17, inj 1 fuse 22, pcm 16, pump fuse 13. on bcm side we did btsi bu fuse 21, bcm 13 fuse 22, ipc fuse 19. all checks done with ignition on and engine off. all voltages were the same as the battery voltage,.

Since the issues are randomly generated and fixed with the squeezing and flexing of the bcm plug, do you think it is more than likely within the bcm or should we continue to fish?

Thoughts?

If I had to do this for a living, I'd be in the rubber room by now.

Don

donjegge

Oh and I should note there is still no appreciable parasitic drain. At least that makes me feel good!

dadaroo

Wow, how lucky can one person get? Pull your DIC codes first and record and post them. Next clear them all and post what comes back and let's start from there.

Flexing the BCM plug to change things would seem to be a "tell". Of course the serial bus Star connectors are close to it so I don't want to jump to conclusions.

donjegge

Well dadaroo, i can't get any codes to display, because i couldnt get the dic to come up. i got messages but when i press and keep the options button in and press fuel 4 times there was no display. nothing. craig the smart guy (cause i'm the dumb guy who owns it) says thats because there is no data link connection.

4DRUSH

I would unplug the serial bus Star connectors, that seems to be the cure all here lately. Good Luck

Bill Curlee

EITHER,,,,,,,,,,,,,,,,,,, You are not doing the DTC entry properly OR there is an issue with COMS between the modules.

What does your IPC Digital and ANALOG volt meters read??

Is your battery 100% fully charged and in proper order???

Next to the BCM in the passengers footwell is a set of slim connectors.. Can you pop the TOP off both connectors and read the resistance to ground to each pin?



Bill