Battery drain

2003 BMW 530D

380,000 MILES • 3.0L • 6 CYL • TURBO • 2WD • MANUAL

EDVINAS KURAPKA

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Something makes battery to drain, i found that disconnecting cas module stops battery drain. But while car in sleep mode amperage show 0.3 amps i disconnected battery and connect again then every think go to sleep and amperage meter show 0.03 amps. But when i unlock car and lock it again it would not go to sleep again. Can it be faulty cas module. I checked all fuses just number 7 stop drain it is for cas module also removing replay 30g stop drain.

Sep 10, 2020 at 11:49 AM

KASEKENNY

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I think you figured it out. The car activation module when reset by the battery disconnect and you plug it back in causes the module to remain asleep. however as soon as you activate it again by unlocking the doors, it is energized and then does not turn back off.

If the issue was there all the time even after a battery disconnect then I would think you had a wiring issue. However, if removing the power from the CAS causes it to go away, would lead me to replace that module.

Unfortunately I am not finding specific instructions on how to remove and replace this. So I will keep looking but I am sure that you found the issue.

Sep 10, 2020 at 5:37 PM

EDVINAS KURAPKA

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Thanks I will try that.

Sep 11, 2020 at 12:34 AM

KASEKENNY

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Thanks. Keep us posted with how this turns out. Thanks

Sep 11, 2020 at 7:13 PM