2000 Jimmy 4wd 4 door. All 4 of the power door locks are weak, sluggish, sticky, sometimes not going down all the way when locking them. 275,000 miles on vehicle so I can understand they are old. But now I've got a new issue to add to the mix. I shut the door with the key in the ignition while checking the oil today. Afterwards I went to open the drivers door to get in, and the door was locked. I know it's made to NOT lock with the key in the ignition, unless you manually lock it using the outside key cylinder. Many times it has saved me from locking myself out, and I've owned it since 2006. Luckily I always carry spare keys in my pocket so I was able to get in.

So on the locks being slow, is it possible to fix that by removing the door panel and cleaning and lubing everything latch and lock related? All 4 doors are like this, and I find it hard to believe all 4 actuators are failing at the same time. But all 4 would have the same years of dust and gunk on them. Has anyone had good results from cleaning, that returned the snappiness to the power locks?

On the drivers door locking itself with the keys in the ignition, I don't know where to start. Does anyone know how/where the ignition and driver side interact to prevent locking when the key is in the ignition? Is there some sort of sensor or switch between them that can go bad? This also just started....I have to press the key fob button a few times to get the drivers door unlocked from outside. The other doors unlock with the first press. I've watched the inside lock mechanism, and with each press it raises bit by bit until it's unlocked. Help?

 

What is the resting battery voltage at the battery terminals right before this happens?

George

 

I would venture a guess that some kind of poor contact and/or grounding issue is at play with the lethargic locks.

As far as having the truck lock itself, I would suspect a sticking or faulty lock switch. THIS POST has most of the relevant diagrams that should help you start diagnosing this situation; it is missing the diagram that shows the individual door lock switches...

 

I'm not great with diagrams, but since I don't see the ignition switch anywhere in those, i guess the "key in signal" between ignition and drivers door switch is through the bcm?
Could one questionable door switch cause them all to be weak? Years ago the alarm would sometimes go off when it rained and I found that the passenger front door was leaking. It would drip right on that switch cluster, so I think it was shorting something that made the alarm activate. I covered the switches with saran wrap and it never happened again. I'm thinking there could be corrosion in that switch cluster or wiring in that door.

 

I had a driver's side door lock that gradually got "weaker" and then unable to lock electronically. It turned out that the wire that would provide the voltage to the locking solenoid on the lock mechanism had been nicked where it passed through the door jamb inside the protective accordion tube. It got nicked when a previous owner had some sort of extra electronics installed. Over time the wire under the nicked insulation corroded and one by one the individual wires inside broke increasing its resistance and lowering the current it could send to the solenoid. This would be hard to detect with a volt meter because the added resistance in the wire would not be able to be detected with only a measurement of the voltage at the lock electrical connector. Instead the wire to the lock solenoid would need its resistance checked along its length to determine if that is the culprit and where the high resistance could be.

 

It's been too cold here to do anything, but we're having a warm up this week so I plan to work on the Jimmy. The locks do work better when it's warm out, but the driver's still only pops up about halfway. I figured out it wasn't actually locking itself at times...it was just falling back down to the locked position because it was barely at the unlock point. It started locking me inside while driving on our bumpy roads, without the actuator activating. I'll check back in after I tear into it.