The battery went down on my 1991 BMW 525i after.

Tiny
KEBARTLOW
  • MEMBER
  • 1991 BMW 525I
  • 225,000 MILES
The battery went down on my 1991 BMW 525i after having sat for a year; over which time I replaced the factory radio with an aftermarket stereo. After charging the battery, I have found that the car is immobilized mode with the alarm sounding. I have tried entering a 4 diget code in the OBC to disarm the alarm but it will not reset. I've even tried disconnecting the battery and touching the cables together for 30 seconds, but to no avail. I would rather do away with the alarm system all together. Can someone please tell me how to either remove of reset the system PLEASE!
Sunday, October 21st, 2012 AT 3:46 PM

6 Replies

Tiny
ASEMASTER6371
  • MECHANIC
  • 52,796 POSTS
Factory or aftermarket?

Roy
Was this
answer
helpful?
Yes
No
Sunday, October 21st, 2012 AT 5:41 PM
Tiny
DOCHAGERTY
  • MECHANIC
  • 9,603 POSTS
A stock alarm is removable and the unit resides in the area around the glove box and is accessed through the under dash on the passenger side. Just disconnect it and the problem should be solved. Let us know if you have questions, Dr. Hagerty
Was this
answer
helpful?
Yes
No
Monday, October 22nd, 2012 AT 1:19 PM
Tiny
RIVERMIKERAT
  • MECHANIC
  • 6,110 POSTS
Just to clarify, you should be looking for a control unit (box, usually black or silver) with a 20-40 pin connectors, one of which might be just black and red for power, 4 for door locks, and 10-15 for sensors and other controls.

I also show a "general module' in the passenger compartment fuse/relay block.
Was this
answer
helpful?
Yes
No
Tuesday, October 23rd, 2012 AT 12:36 PM
Tiny
KEBARTLOW
  • MEMBER
  • 3 POSTS
Since my original question regarding my immobilization alarm question, I have since changed out the OBC. The alarm has stopped and now the display says: PPPP what do I do Now?
Was this
answer
helpful?
Yes
No
Thursday, October 25th, 2012 AT 7:37 PM
Tiny
KEBARTLOW
  • MEMBER
  • 3 POSTS
New update: OBC is functional now but still no ignition or radio function. Next step?
Was this
answer
helpful?
Yes
No
Friday, October 26th, 2012 AT 5:53 PM
Tiny
RIVERMIKERAT
  • MECHANIC
  • 6,110 POSTS
1. With the car and power off, plug in the new OBC unit.

2. Turn car power on with key, but do not start car (radio works but ignition is not cranked.)

3. Push the "Code" button.

4. Push the S/R button.

5. Now without powering the car electrical system down, start the car.

6. Program your new unit which should be displaying 00.00 for the time setting.
Was this
answer
helpful?
Yes
No
Saturday, October 27th, 2012 AT 1:04 AM

Please login or register to post a reply.

Related Disarm Content

Security System Reset
GUIDE
Security System Reset
Need to reset the security light in your car? If the security light is blinking the immobilizer system is enabled and will not allow the car to start.