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Power Door locks not unlocking
02-15-2012, 02:26 PM
I have an '05 Malibu Maxx. The power door lock switch on both the drivers and passenger side will not unlock the doors but both switches work to lock the doors. The key fob is broken so I'm not sure if the doors will unlock with it. The power door lock fuse is good and there doesn't appear to be a relay for them. I'm thinking maybe there's a problem with the switch on the driver's side as the passenger side is probably wired through it as well but wanted to see if anyone has any other suggestions before ripping the door panel out to get to it.
02-15-2012, 05:32 PM
You may have a problem with the BCM as it looks for a resistance value for the lock and unlock. The pass side switch does not run through the drivers switch. A scanner with the ability to read live BCM data is needed to accuratly diagnose your door locks.
02-15-2012, 05:50 PM
I tried removing both both locks and closing the circuit with a jumper wire. The doors will still lock but not unlock so at least I've ruled out the switches. Is there a good workaround without messing with the BCM? That sounds expensive, I know it will cost $100 just to have a dealer hook up a scanner.
02-15-2012, 06:07 PM
it is probably the bcm or possibly a bad ground.
02-16-2012, 05:52 AM
This has been discussed at least once at length in a previous thread. Newbies need to check out earlier threads before starting new ones. And don't get me started on passlock threads.
02-16-2012, 11:23 AM
I understand that a dealership visit is not always an option. If you do decide to go in, please let me know as I would like to be available to assist as best as I can.
GM Customer Service
11-17-2012, 01:57 PM
The lock actuators are crap, see info at this forum: After reading, I bought an actuator for $1.74 on e-bay with free shipping.....you read that correctly
11-17-2012, 05:15 PM
This is an old, unresolved post.....
As for the actuators, maybe they are crap.......but chances are they don't fail at the same time(especlialy if a 4 door)...chances are the switches don't fail at the same time....
The fact that the doors lock tell me the circuits to the switches are ok, and the circuits to the actuators are ok.....the fact that they lock but don't unlock, makes it almost certain that the actuators are ok......the problem is either the BCM or the unlock relay in the BCM.....
Not familiar with cars other than GM, but I wonder if they have put all their eggs in one basket, like GM did.....the BCM is the "traffic cop" for all electrical systems in the car......so if the BCM goes down, depending on which part of it does, then you can lose one or more systems.....Ran into this with
Grand Prix's.....Wipers didn't work....Now I have worked on wipers for years....you have a motor......a module cover.......the switch.....and wiring.....it was an intermittant problem.....worked every time I checked it....finally checking the schematic, found out communication went through the BCM......Grand Prix's were the first ones I found this in.......I lucked out by constantly turning the wipers on/off while tapping the BCM.....
Not an inexpensive part, and to top it off, it has to be programmed, CORRECTLY, on the first shot, because in some BCM's(not all), you can't go back and make changes, later....it's "LOCKED" as far as setup goes....so if something is in your vehicle that is not programmed into the BCM, it won't work.....sorry, but when it comes to programming, a dealership is your best bet....
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