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car starter won’t lock/unlock door

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=135468
Printed Date: July 05, 2025 at 7:50 PM


Topic: car starter won’t lock/unlock door

Posted By: jb456
Subject: car starter won’t lock/unlock door
Date Posted: December 05, 2013 at 1:33 PM

Hi Guys,

Thank you in advance for any insight you can give me!

I have a 2005 Equinox that when I purchased a few years ago the previous owner had a car starter installed.

The entire time I've had the car the starter, door locks, alarm worked absolutely fine.

Over a year ago I lost my remote and never bothered going to get a new one until now... Took the guy a minute to program a new remote, he turned the key on/off a few times, hit the little car starter button which is under the hood and the new remote was programmed.

The problem is the doors don't lock or unlock with the remote now.

When I hit the lock button the lights flash as it should but the doors don't lock... same when I hit unlock, lights flash nothing else.

When I hold the lock button it activates the alarm and horn beeps... unlock deactivates it.

Car starter works find to turn on and turn off the car with the button.

Just the door locks don't work.....

Does anyone have any idea what it could be that is causing the problem? Like I said nothing was changed or done with anything since I first bought the car... the door locks worked fine for over 3/4 years until I lost the remote.

The guy at the shop said I could make an appointment so he can go through all the wiring and see if something is loose. I'm skeptical cause why would everything else work?


Could it be a fuse or something?

Unfortunately no idea the model of the car starter or for that matter even where the location of it is... The only thing is the antenna on the window says FM 433-100

Any help would be appreciated.. Thank you!



Replies:

Posted By: kreg357
Date Posted: December 05, 2013 at 4:14 PM

Your Equinox has (+) door locks.  Depending on the brand and model of the R/S system, it might not be able to handle the locks
with a direct connection.  The fact that the R/S properly flashed the Parking Light with each lock command means that the remotes
are working OK.  Standard troubleshooting assumption is that only one thing happened / is wrong.  There are still a lot of possibilities
that could cause your problem.  Here are a few :

1.  Your R/S system has built in door lock relays and the wire that supplies the +12V input for the lock relays has come loose or the
in-line fuse blew.
2. Your R/S system only has (-) lock outputs and a 451M door lock module was also installed.  It's power connection is loose or it's
fuse blew.
3. Your R/S system only has (-) lock outputs and a 451M door lock module was also installed.  The harness that's connected to the
R/S's 3 Pin door lock plug has come loose.
4. Slight variation as #2 but the installer used standard Bosch style relays instead of a 451M module and the +12V power wire
is loose.
5. Slight variation as #3 but the installer used standard Bosch style relays instead of a 451M module and the +12V power wire
fuse is blown.
6. The R/S systems door lock output circuit has gone bad.

As you can see, there are a lot of possibilities.  And all of the above could be wrong if the installer used a full featured bypass module
like the iDatalink ADS DL flashed with the DL GM4 firmware.  You will have to go under the dash to examine the modules used, fuses
and connections made to narrow down the problem.  Having a Digital Multi Meter would be a good thing.



-------------
Soldering is fun!




Posted By: jb456
Date Posted: December 05, 2013 at 4:29 PM
kreg357 wrote:

Your Equinox has (+) door locks.  Depending on the brand and model of the R/S system, it might not be able to handle the locks
with a direct connection.  The fact that the R/S properly flashed the Parking Light with each lock command means that the remotes
are working OK.  Standard troubleshooting assumption is that only one thing happened / is wrong.  There are still a lot of possibilities
that could cause your problem.  Here are a few :


1.  Your R/S system has built in door lock relays and the wire that supplies the +12V input for the lock relays has come loose or the
in-line fuse blew.
2. Your R/S system only has (-) lock outputs and a 451M door lock module was also installed.  It's power connection is loose or it's
fuse blew.
3. Your R/S system only has (-) lock outputs and a 451M door lock module was also installed.  The harness that's connected to the
R/S's 3 Pin door lock plug has come loose.
4. Slight variation as #2 but the installer used standard Bosch style relays instead of a 451M module and the +12V power wire
is loose.
5. Slight variation as #3 but the installer used standard Bosch style relays instead of a 451M module and the +12V power wire
fuse is blown.
6. The R/S systems door lock output circuit has gone bad.


As you can see, there are a lot of possibilities.  And all of the above could be wrong if the installer used a full featured bypass module
like the iDatalink ADS DL flashed with the DL GM4 firmware.  You will have to go under the dash to examine the modules used, fuses
and connections made to narrow down the problem.  Having a Digital Multi Meter would be a good thing.




Hi Kreg,

Thanks for the reply.

Would this be the same for an old install?

For almost 4 years the door locks on the remote worked perfectly fine....

Nothing was touched or changed in regards to the R/S.... the only thing is that I lost my remote.... Now with the new replacement remote the door locks don't work :(

Thanks again bud for you help, much appreciated!




Posted By: kreg357
Date Posted: December 05, 2013 at 4:47 PM

I can remember doing a 2005 Equinox LT with Factory Alarm with a Ultra Start U1272 and an iDatalink ADS DL flashed w/DL GM4 firmware about 5 years ago, so yes all of this technology was available then.

As mentioned, the new remote's lock button causes the vehicles Parking Lights to flash, so that much is working.  Agreed, simply loosing a remote and programming a new one shouldn't damage, change or loose anything but the locks don't function anymore.  It could be a quick / simple fix but some more investigation / troubleshooting is required.



-------------
Soldering is fun!




Posted By: jb456
Date Posted: December 05, 2013 at 5:50 PM
kreg357 wrote:

I can remember doing a 2005 Equinox LT with Factory Alarm with a Ultra Start U1272 and an iDatalink ADS DL flashed w/DL GM4 firmware about 5 years ago, so yes all of this technology was available then.


As mentioned, the new remote's lock button causes the vehicles Parking Lights to flash, so that much is working.  Agreed, simply loosing a remote and programming a new one shouldn't damage, change or loose anything but the locks don't function anymore.  It could be a quick / simple fix but some more investigation / troubleshooting is required.




Kreg thanks for the additional reply.

Well funny thing is the system has resolved itself. Not sure how, not even sure if it's possible lol but for some reason it's all working now.

Just returned from the store and when turning off the car I didn't realize it but the key was not fully on off... kinda between off and ACC...

I also triggered the alarm slightly early while the passenger door was still open

Anyways as we were walking in we heard the sounds of the locks activating. Sure enough went back to the vehicle and tried locking and unlocking the doors a couple times and it's working.

No idea if somehow the system reprogrammed itself with the passenger door open or because the key was not fully off but for whatever weird reason everything is working perfectly now.

Thanks for taking the time to respond to my thread. I appreciate that. Happy holidays to yourself and family.






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