OK, new thread, new question. I bought this 2008 GM HD with inoperable door locks. I figured it would be an easy fix. Then i did some online research. Apparently, its rampant with this year model truck. And I really cant understand why it hasnt reached the recall level with GM yet. Anyone else having ths problem? and if so, whats the solution? Thanks

How are they inop? Like, they don't work at all? Or they don't work with the keyfob, or they don't work with door button...what?

Well it depends. The only time the passenger door works is when I shift into drive or into park. I might get the passenger door to open once with the power switch, but thats it. The driver never works thru the switch. The passenger door lock seems sluggish. Hard to explain, but a serious safety issue in my opinion.

So you're saying that it'* an electrical problem then? Not that they are inop completely. Correct?

I wouldnt call it an electrical problem. Its more like a weak solenoid. The research ive done suggests a bad batch of solenoids. Google it and see what you come up with. GM is offering no remedy even though the problem is wide and well known. Even by them.

try cleaning and squirting some white lithium grease on the solenoid and linkage

Solenoids are an electrical component. They can be pulled and bench tested with a DMM to see if they are good. If they are, what JW said could be the fix. If they are bad, replace and also grease the linkage.

you can take solenoids apart and clean them, they come with some grease that traps dirt, so if you clean and grease them they will work sometimes. as long as its not gm spec thing that wont come apart.