avital 2101l, doors won’t unlock, ’08 cobalt

Printed From: the12volt.com
Forum Name: Car Security and Convenience
Forum Discription: Car Alarms, Keyless Entries, Remote Starters, Immobilizer Bypasses, Sensors, Door Locks, Window Modules, Heated Mirrors, Heated Seats, etc.
URL: https://www.the12volt.com/installbay/forum_posts.asp?tid=137239
Printed Date: May 10, 2025 at 2:18 AM

Topic: avital 2101l, doors won’t unlock, ’08 cobalt

Posted By: grblifebythrns
Subject: avital 2101l, doors won’t unlock, ’08 cobalt
Date Posted: September 11, 2014 at 12:28 PM

I am installing Avital 2101L keyless entry on a 2008 Chevy Cobalt. The key fob will lock doors but not unlock them. Both lock/unlock buttons on the key fob will perform the lock function.

This is how I have the door locks wired:

posted_image

Is it a wiring issue? Does the module need to go through it's "learn" routine?

I could use some ideas if you have any! My brain is fried. And I'm hoping my relays aren't.

Thanks!

-grblifebythrns

Replies:

Posted By: kreg357
Date Posted: September 11, 2014 at 2:34 PM

Did you place a 1/2 watt 1500 ohm resistor in the Unlock Output line anywhere? (H1/8 )

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Soldering is fun!

Posted By: grblifebythrns
Date Posted: September 11, 2014 at 6:35 PM

no, I didn't... was that the missing piece?

Posted By: kreg357
Date Posted: September 11, 2014 at 6:44 PM

Yes. Your Cobalt has a "one-wire" door lock system. The White wires at Pins 6 and 7 are electrically and
functionally the same. Here is a photo from AstroChart :

posted_image

To Lock the doors, a straight (-) pulse to either wire will do the trick. This is currently working fine.

To Unlock the doors, a (-) pulse thru a 1500 ohm resistor to either wire is needed. Just solder in the correct resistor
value and you should be good to go ( your Avital system has built in lock relays ).

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Soldering is fun!

Posted By: grblifebythrns
Date Posted: September 14, 2014 at 1:56 AM

I got the resistor and it works! Thank you for your help!

I'm pretty sure I have other problems now, though:
Pin 6 is working with either the lock or unlock output (from the Avital) connected but Pin 7 does not register a response either way. Seems like I have a faulty wire?

I might just have to take it to the shop next week.

Posted By: howie ll
Date Posted: September 14, 2014 at 3:29 AM

Ignore the fact that pin 7 doesn't work connect both lock and 1500R unlock to pin 6. If all else works, don't worry.

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Amateurs assume, don't test and have problems; pros test first. I am not a free install service.
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