(another) Service 4wd

[SnowDrifter]

Had another one pop up. Managed to pull a code this time. Message went away after engine restart, works fine now. Bleh.

Anyone have a wiring diagram so I can check pinouts and verify it's the switch before I shotgun said switch?

 

[SnowDrifter]

Bump? Anyone?

I'll take a wiring diagram or any info for the cause behind these switch failures. I'm not opposed to rebuilding it myself on account of aftermarket parts being such a shit show. Dealer wants 170 for it. Local store wants 105. Amazon is like 20 bucks but I have some doubts about any amount of build quality / QC during manufacturing on those

 

[Doubeleive]

Bump? Anyone?

I'll take a wiring diagram or any info for the cause behind these switch failures. I'm not opposed to rebuilding it myself on account of aftermarket parts being such a shit show. Dealer wants 170 for it. Local store wants 105. Amazon is like 20 bucks but I have some doubts about any amount of build quality / QC during manufacturing on those

I would roll with a used oem one from the local scrap yard if they have any usually they are snatched up quick, lkq might have one, they have a circuit board inside not sure what goes wrong with them.

 

[Fless]

@SnowDrifter, two-speed transfer case with round Auto button at top of switch?

EDIT: https://www.tahoeyukonforum.com/threads/03-4x4-issues.112093/#post-1345015

 

[SnowDrifter]

@SnowDrifter, two-speed transfer case with round Auto button at top of switch?

EDIT: https://www.tahoeyukonforum.com/threads/03-4x4-issues.112093/#post-1345015

You, sir, are a saint!

 

[Fless]

The two I have for my '04 (I have a spare from U-Pull) are both apparently OE and have "TRW" molded into the backside. I've never tried others, as these have so far passed the resistance tests and I've replaced the backlights in both.

I'd be interested in if your switch fails the resistance test.

 

[Roger L]

I had 2 new ones from Napa work for a week, the last one passed resistance test, ordered one from an Oregon GM dealer and it says made in China on the back, it passed too, still no worky.

 

[Fless]

If you haven't checked and cleaned the two ground wires on the body behind the LF wheel, one of those is for the 4x4. Think it goes to the harness for the TC control module under the dash. I believe there is also a splice in that wire around (underneath) the brake booster; follow the ground wire up the firewall to see if that's a good connection.

A Tech 2, and maybe other scanners, will read the reference and return voltages to/from the encoder motor. I have no idea what the return voltages should be, but the reference is either 5v or 8v, depending on your system.

 

[SnowDrifter]

The two I have for my '04 (I have a spare from U-Pull) are both apparently OE and have "TRW" molded into the backside. I've never tried others, as these have so far passed the resistance tests and I've replaced the backlights in both.

I'd be interested in if your switch fails the resistance test.

If you haven't checked and cleaned the two ground wires on the body behind the LF wheel, one of those is for the 4x4. Think it goes to the harness for the TC control module under the dash. I believe there is also a splice in that wire around (underneath) the brake booster; follow the ground wire up the firewall to see if that's a good connection.

A Tech 2, and maybe other scanners, will read the reference and return voltages to/from the encoder motor. I have no idea what the return voltages should be, but the reference is either 5v or 8v, depending on your system.

Ref voltage for mine is 5v.

Switch tests out good, though I did note pin tension on B of C2 is lame. Seems to correspond with some flickering lighting on the thing when I go over bumpy roads. Not really confident that would be my fix though.

One of the pins (and I already forgot which one) had a bit of a patina on it. Probably from an interior water leak I had last year

Will clean up those grounds you mentioned, adjust pin tension, button her back up and see where that gets me. Given how intermittent the thing has been, and the switch testing good, I'm temped to believe at this point it's just a garbage connection somewhere *knock on wood*

 

[SnowDrifter]

Well she's all buttoned back up. Works now so at least I managed not to break anything! Though how intermittent this is it'll be a hot minute before I know of it worked or not. Will update this in the future