Question on BMW 3-Series E36 DME Repair

I have a 98 382I.The car has a massive battery Drain that I have been looking for. The car usually runs like crap. The IAC valve buzzes reguardless if the key is in or not and on any position of the ignition. I look into the wiring diagram and which the IAC valve and oxygen sensors car throws codes for them and I've replaced one of them and the code reocurs after replacement seem to tie into the engine control Module relay. Removing the EMC relay, I have found that there are two pins that have a constant 12v reading and one that has about 4 volts. I can also start My car without the relay in, if I'm not mistaken the car should not be able to do that right? Does that mean there is some sort of short circuit giving them power, thus the iac valve buzzing reguardless if the key is in the on position and even with the relay out?

__________________
This post was auto-generated based upon a question asked on our tech article page here:

[Nick at Pelican Parts]

Sounds like you have a parasitic draw. You'll want to monitor the draw on the battery when the vehicle is asleep. Here is a list of the specifications: http://autotechdiagnostics.com/?p=185
Once you confirm there is a draw. You will have to isolate the circuit with the draw. Then determine which components on that circuit is causing the draw You can isolate by removing fuses. be sure to have all the latches on the doors and hood closed (pin switches) so the vehicle will sleep during testing. If it wakes up, you will have to wait until it goes to sleep again.


- Nick