Mysterious battery drain

[Timur]

[FONT=verdana]This is about a friend's 9-5 M2011:

there is a huge battery drain when the car is parked for an extended period of time (like overnight), regardless of if the car alarm is on or off. If the battery is freshly charged, current leakage is next to zero (~100mA). But several hours later, leakage current springs up to about 6.5 A.

What apparently happens is that when the engine is switched off, the current quickly falls down from about 6.5A to ~100mA as various systems shut down conseсutively. After a while battery voltage settles down, and at some point several systems turn back on spontaneously: main engine relay, chassis control system, rear differential control module -- and stay on until full discharge of the battery. If the battery's voltage is below certain level (~12.5V) from the very beginning (i.e. when the engine is switched off), some of these systems never shut off.

Any ideas what's going on?

The info about what happens is from a local mechanic (a very experienced and knowledgable in older models, but not the new 9-5), translation is mine and can be not quite correct.[/FONT]

[nordwulf]

Did you find out more about this problem? Which country are you in?

[Timur]

[FONT=verdana]Well, out of desperation I pleaded to ANA [/FONT]Trollhättan[FONT=verdana], and my message was forwarded to nice people of Saab Parts, who kindly replied with a very helpful message, and are still trying to help us out via email.

Turns out, this is a known issue: the bus, or one or more of the systems "stay awake", and unfortunately there is a whole bunch of possible causes for that, starting with parking brake switch or button on the automatic gear shift lever getting stuck -- to water getting into connectors in the rear wheel house and damaging them -- to God knows what else. They are still searching... I'll post here when (and if) they manage to fix it.

I'm in Moscow, Russia. BTW, the car in question is the one used to "unveil" the new 9-5 in Moscow, and as far as I understand it is the only new 9-5 sold in Russia by a Saab dealer (a former Saab dealer that is) as a new car (there might be a few imported as second hand).[/FONT]

[kanundrum]

I may have this on my 9-4x

When I put the multimeter and put it on the 10amp setting and then plugged the probes into the 10a outlet and then tried a draw off test, it registered 8amps

I was shocked then I did it a few more times and kept on getting the same thing....


Very odd indeed. Now my battery is dead and I have to get a new one not sure what the deal is here.

[kanundrum]

Now its doing 6amps so I am not 100% sure but it sounds like the same problem as this 9-5