Power locks don't work without ignition on

saurkraut

New member
I have searched for a while now and haven't found anything that sounds like the problem I am having. Most seem to have something to do with the door actuators or key fobs not working, etc.

My power locks work just fine, but only when the ignition is in the ON position. When I turn it off, the rocker switch doesn't work and I don't hear any relay clicking from the body ECU. It used to be that when I would turn the engine off after a trip, the light on the power window switch would stay on, and I could use it to roll up or down the window. Now, as soon as I turn the key off, that light goes out and I am no longer able to use the power lock rocker to lock or unlock the doors. I have checked all the fuses and all are good, under hood and inside behind the kick panel. The door locks are not weak by any means so I know its not an actuator problem. Just seems weird that it appears they are only getting power when the ignition is on.

Nothing in my rear hatch works (wiper, window up or down), never has and I think its the control module back there that is the problem - but, the power locks have always worked regardless of this issue. Does this module tie into the same circuits as the body ECU? I've thought about disconnecting that module in the rear hatch to see if this solves the issue. At times, when the power locks worked correctly, the rear hatch lock would not lock/unlock and I had to operate that manually, but the door locks have always worked regardless.

Sorry for the long post, just wanted it to be as detailed as possible. Thanks for the help. I hope I don't have to replace the fuse block/body ECU in the kick panel. From what I can see it's not cheap. But I'm not thinking it is since they work just fine when the ignition is on.
 
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I have searched for a while now and haven't found anything that sounds like the problem I am having. Most seem to have something to do with the door actuators or key fobs not working, etc.

My power locks work just fine, but only when the ignition is in the ON position. When I turn it off, the rocker switch doesn't work and I don't hear any relay clicking from the body ECU. It used to be that when I would turn the engine off after a trip, the light on the power window switch would stay on, and I could use it to roll up or down the window. Now, as soon as I turn the key off, that light goes out and I am no longer able to use the power lock rocker to lock or unlock the doors. I have checked all the fuses and all are good, under hood and inside behind the kick panel. The door locks are not weak by any means so I know its not an actuator problem. Just seems weird that it appears they are only getting power when the ignition is on.

Nothing in my rear hatch works (wiper, window up or down), never has and I think its the control module back there that is the problem - but, the power locks have always worked regardless of this issue. Does this module tie into the same circuits as the body ECU? I've thought about disconnecting that module in the rear hatch to see if this solves the issue. At times, when the power locks worked correctly, the rear hatch lock would not lock/unlock and I had to operate that manually, but the door locks have always worked regardless.

Sorry for the long post, just wanted it to be as detailed as possible. Thanks for the help. I hope I don't have to replace the fuse block/body ECU in the kick panel. From what I can see it's not cheap. But I'm not thinking it is since they work just fine when the ignition is on.

OK so you have 3 separate problems that may or may not be related. I'm not going to address the back door issue except to say you need to check the connector at the top of the door/opening before anything.

The window operation after the key is turned off is controlled 100% by the Body ECU and is only cancelled before the 43 second mark if the driver's door is opened. So if the LF Door courtesy switch is working, you need a new Body ECU.

The door locks are also controlled by the Body ECU, power is from the 30A power fuse, the 10A ECU-IG fuse, both in the left side junction block the 15MPX fuse in the engine room fuse block.

Since the door locks work with the key on, we can effectively rule out the switches, and the circuits to actuators and switches. Really, that only leaves the power circuits to the Body ECU, and the ECU itself. If the MPX fuse and the power fuse both have power on both sides with the ignition off. It's time to change the Body ECU!

:faint:
 
Thanks! I was hoping you or TheDurk would chime in on this one. I'm not concerned with the rear hatch functions working. I've been working around that since I've owned it but the power locks have always worked so I didn't think that would have anything to do with it. To be clear, I know about the timer before the LF door is opened, the lighted window switch would stay lit before I opened the door before and now it doesn't.


I really don't want to have to pay for the Body ECU but sounds like I'm going to have to. I ran my meter on all the fuses yesterday, but all I did was check for continuity and not power. I'll check for power on both sides of all those fuse connections to be sure before I make my final decision to do it or just deal with it for now. By the way, what all does the MPX-B fuse/circuit provide power for? I don't have a schematic to find out. Thanks again!
 
Thanks! I was hoping you or TheDurk would chime in on this one. I'm not concerned with the rear hatch functions working. I've been working around that since I've owned it but the power locks have always worked so I didn't think that would have anything to do with it. To be clear, I know about the timer before the LF door is opened, the lighted window switch would stay lit before I opened the door before and now it doesn't.


I really don't want to have to pay for the Body ECU but sounds like I'm going to have to. I ran my meter on all the fuses yesterday, but all I did was check for continuity and not power. I'll check for power on both sides of all those fuse connections to be sure before I make my final decision to do it or just deal with it for now. By the way, what all does the MPX-B fuse/circuit provide power for? I don't have a schematic to find out. Thanks again!

It provides power to the Mulitplex comunication system between the back door ECU and the Body ECU. The symptoms include:

Horn
Mirror heater
Door locks
Rear window
Rear defogger
Rear wiper
Theft deterrent
Wireless door locks

:hunter:
 

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