No 4×4

[SnowBlazer]

Hey all. I had a "service 4×4" light come on a few weeks ago and thought nothing of it. Restarted the truck and it went away. Cool. Just a little hiccup. Today, I was pulling our of the driveway and my 2hi light blinked for a good 15 seconds and turned off. I shut down the truck and everything looks back to normal. I got a little paranoid and tried switching between the selections and they all flash but nothing engages. No sounds like anything is even trying to engage. I'll grab a video in a bit. Just curious if it's the switch or if I'm looking at a bigger monster. If it's going to cost more than $1k to fix, she's going to the trade in lot.


Thanks guys!!
Ryan

 

[Sparky]

What year is yours again?

When mine started doing that it was the switch. It was only occasional and random, usually came back next time I fired up the truck a few hours later, but it gradually got worse and I didn't trust it with winter coming last year. Put a new switch in it and all was well with the world.

The other thing it might be is the TCCM but a used one is only like 50 bucks. Usually an 02 TCCM just rolls over and dies entirely though (mine did), though a failing TCCM in general could just start acting stupid randomly.

Those are the two most likely suspects, in order of suspectivity (is that even a word?), and neither are expensive at all.

 

[Mooseman]

His is an '02, like mine, and is acting exactly like mine did but only in -20C. All the lights would flash, go out and the service 4x4 would come on. You probably have the flaky 1st gen TCCM. I replaced it with one from a later year from the pick-a-part (cheap) and has been good since.

 

[Sparky]

Funny how two different problem parts can exhibit similar symptoms.

If he hadn't swapped the TCCM then it may be worth doing both switch and TCCM. Still going to run less than $100, the switch is 14 years old now, and an 02 TCCM is bound to fail eventually anyway.

 

[SnowBlazer]

If he hadn't swapped the TCCM then it may be worth doing both switch and TCCM. Still going to run less than $100, the switch is 14 years old now, and an 02 TCCM is bound to fail eventually anyway.

I was thinking of going that route actually anyways. One question I do have is, if I buy one on eBay new, will I need a dealer reflash?

 

[Sparky]

A new one would require a flash to get it programmed for the first time. But just get a used TCCM from a Trailblazer or Envoy (basically no AWD models like the Buick or Saab) and stick it in there. No programming necessary that way.

 

[SnowBlazer]

A new one would require a flash to get it programmed for the first time. But just get a used TCCM from a Trailblazer or Envoy (basically no AWD models like the Buick or Saab) and stick it in there. No programming necessary that way.

Cool. Thanks dude. Might actually cruise by Pull and Pay tomorrow then. I need fuses and what not. The switch I will buy new because why not.

 

[Sparky]

That's what I'd do. Less chance of getting a buggy one anyway.

I stuck with AC Delco for the switch. Dorman makes one, but there have been complaints about it (as usual for Dorman electronics) and the price difference wasn't that drastic.

 

[SnowBlazer]

That's what I'd do. Less chance of getting a buggy one anyway.

I stuck with AC Delco for the switch. Dorman makes one, but there have been complaints about it (as usual for Dorman electronics) and the price difference wasn't that drastic.

My only complaint with the new style is, they used arrows instead of writing it all out. Kinda looks dumb imo. But I gotta fix this.

 

[Mooseman]

Some have been able to save their switch by just switching it back and forth (with ignition off) numerous times to clean out the contacts. I'd replace the TCCM first and check. If it's still wonky, then the switch.

 

[triz]

Have you checked your axle disconnect? Mine was chewed up.

 

[SnowBlazer]

Update: both the TCCM and the selector switch have been replaced. Still same problem, is there a TCCM fuse?

 

[littleblazer]

Under the hood it's labeled atc or transfer case or tccm or something like that. Unplug it with the new parts let it sit and then try seeing if it works.

 

[SnowBlazer]

Under the hood it's labeled atc or transfer case or tccm or something like that. Unplug it with the new parts let it sit and then try seeing if it works.

Idk what's going on honestly. I can hear the TCCM move back and fourth with the engine off. But it quits after like 2 tries

 

[Sparky]

Encoder motor issue?

 

[littleblazer]

Encoder motor issue?

Splined disconnect maybe? Encoder makes more sense

 

[Sparky]

The actuator is easy to test at least.

 

[SnowBlazer]

The actuator is easy to test at least.

I just had that done at Woodman Nissan last year.

 

[SnowBlazer]

Encoder motor issue?

Splined disconnect maybe? Encoder makes more sense

The actuator is easy to test at least.

Alright so how do I go about testing whether or not it's the actuator or splined disco? I don't really want to continue throwing parts at this issue but I really needs to be fixed.

 

[dmanns67]

Some additional reading for you.

http://www.offroadtb.com/articles/tech-docs/what-is-wrong-with-my-4wd-system/

 

[tsmith1156]

Mine is an 05 and has done that once where the 2HI blinked and I got nervous and shut the car off and turned it back on and it was fine so idk what the deal was

 

[SnowBlazer]

I just got out of the junk yard. I got lucky and found an 05 with the T-Case sitting on the ground. Zipped off the 13mm bolts and brought the encoder motor home. Mine was replaced a couple of years back with a Doorman. That might be it as I've herd that their products are not that great.

 

[Sparky]

Would not surprise me, Dorman's electronic stuff tends to be kinda crappy I've found.