TCCM and Shift motor issue

[Woodsman]

I have a 2002 Envoy SLT that I just bought, when I started it up the selector switch would flash, at random and never the same light up 2 hi, 4 hi, or 4 AWD, but not actually do anything.
The indicator light for 4x4 service light was on.
I took the shift motor off and applied power and it would click but not move.
So, bought a new motor, installed, same thing.
So, bought a used tccm from a 04 Rainier p/n 12584313 and installed.
Now the 4x4 service light is out, the selector switch doesn't flash or light at all, and still no four wheel drive.
And yes, I did the fuse thing over and over a 100 times in every combination with and without the old motor, new motor, old tccm, and new one.
I will comment that when I was at the wrecker I did not see a selector switch on the Rainier but it may have been in a different location or removed because the interior of the vehicle was fairly cannibalized at this point.
I have an OBD 2 reader but I don't think it can give me the kind of codes I would be looking for, or maybe I'm just to dumb to know how to use it for more than basic functions?
Any further ideas are welcome.

 

[Woodsman]

Oh yeah, roadie, just got your message about posting.
I was being a blind man, thanks for the speedy reply.
Glad you are so pumped about tccm's cause I'm about to put a big metal lever through the floor.

 

[Robbabob]

First of all, Welcome to the Nation!

Second, never change out parts until you've consulted with The Roadie.

Third, enjoy your new home!

 

[The_Roadie]

Awwww, man - could have saved you a ton of time and annoyance if only you'd found me first.

1) 2002 trucks were NOTORIOUS for having flaky TCCMs. Shun them. Buy one from Ebay or junkyards ONLY from 2003+. Your symptoms are exactly that - flaky 2002 unit. A better part number is 12590220. Aftermarket parts stores now carry or can obtain a lower cost Dorman replacement that should be plug and play - Dorman 599-113

2) Never use a Rainier TCCM without saving up to go to the dealer and forking over $90-150 for ten minutes work for them to reprogram it. The Rainier is an AWD model, meaning it's ALWAYS in what we know of as A4WD mode. There is no mode selector switch. It needs to be reprogrammed. Until that's done, it will not play nicely with your system. The AWD models have a 5-pin transfer case encoder motor, you have the 7-pin. Read on for why that's important.

3) Fatherly advice - don't use the A4WD mode. It can potentially damage the transfer case and it doesn't help as much as everybody thinks in rain. It's not a true AWD system like Subarus, for instance.

4) If you didn't get the memo, and you probably did, ALWAYS change the transfer case fluid every 50K. Religiously. Never fail.

5) The encoder motor has seven pins. How did you choose the right ones for a bench test? If you have the schematic and know what you're doing - 1000 apologies.

6) The reason it clicked probably was two of the 7 pins are a solenoid brake that's used for a safety interlock. You can spin the motor each way with proper application of voltage to the motor's two drive pins, but you ALSO have to apply a constant 12V to unlock the solenoid.

7) Hope you got a discount. If only you'd found the forum before you did your pre-purchase inspection.......

8) You DID do a pre-purchase inspection?

9) If you didn't get maintenance records - change EVERY fluid in EVERY reservoir. Trust nothing.

 

[Woodsman]

I suspected the problem was that it was from a AWD Rainier, right part programmed wrong.
And yes, I would never use the 4AWD mode either, where I live in the heavy snow fall area of northern Ontario Canada it's basically 4 x 4 from November to March anyway.
My experience is that the 4AWD was actually a bit dangerous.
Answer to question #5, no I did not have a schematic but I could tell the 3 small wires were connected to the positioner so that left me to conclude the black would be a ground or something like it and the others would be go or no go.
I light touch got the response I was looking for, I admit I didn't know about the brake.
Would be nice to have the schematic.
Not sure what you meant by a pre purchase inspection, do you mean on the car I bought? Yes I did and was aware of the problems with the car, body and interior were 95 % or better and mileage was relatively low for the year in this area, new tires, 118,000 miles, paid $2675.00 cash, about half what they go for in these parts.
No didn't get the memo, but I am sure I will in the weeks ahead be changing many fluids, I never know what a previous owner did or didn't do and it's always best to start fresh.
Generally speaking we pay at least twice as much as we should for parts up here and normally I would buy my part online but I aready had it in the shop and apart so I figured I go with this part, turns out it saved me no time but at least the yard will refund the money no problem.
I did try to get some info from the Trailvoy site but found a awful lot of differing opinions and speculation, I don't really like to work that way, don't have the time for it.
The post I did make drew a response from one of the fellows that moved over here and that proved to be fortunate and I have moved as well.
Can't begin to tell you how much I appreciate your response with details and hope I can be help to the other guys as I am a pretty decent mechanic and know electrical fairly well.
Biggest drawback for me is I drive things forever and my wife told me my 93 S-10 Blazer was smelly and she wouldn't ride with me anymore, so I bought the 2002 Envoy, this is like the starship Enterprise for me.
A whole new level of needless electronics to deal with and I've done fairly well so far, the dreaded door modules are all fixed, ambient temp working now, Bose sound system face plate buttons changed out, rear washers working, headlight washers working,and mirrors working properly.
Now to get the 4 x 4 working and then front crank seal which drips a bit and I hate dripping cars.
So I'll change the tccm again, you say the Dorman 599-113 is plug and play, if so I'll go with that.
Let me know what you think if you have the time and I will post how things turn out, in the mean time thanks a million.
Tom

 

[The_Roadie]

Would be nice to have the schematic.

Just to have them here in this thread, here's what you need:

...new tires, 118,000 miles, paid $2675.00 cash, about half what they go for in these parts.

Very nice. You got a heck of a deal. That's worth it just for the engine and axles.

I did try to get some info from the Trailvoy site but found a awful lot of differing opinions and speculation,

Since most of the active members here WROTE the content at Trailvoy, it's unfortunate that Google leads noobs over there. We'll get indexed higher soon. The corporate third owners of Trailvoy turned it into an ad farm and diverted all the money that could have been used to benefit the members. Only a few goofballs left back there to answer questions incorrectly. They cannot even get a volunteer moderator anymore.

Can't begin to tell you how much I appreciate your response with details and hope I can be help to the other guys as I am a pretty decent mechanic and know electrical fairly well.

That's what an active volunteer support community DOES. Get help...pass it on.

 

[Woodsman]

This is great, if I continue to have problems this will be of assistance for sure.
Stay tuned for more tccm adventures, may have another tccm to try on Monday.

 

[Woodsman]

Picked up a TCCM from an 05 Envoy today for $90.00, put it in at the wreckers ( 5 min.s or less, getting good at this) and it's working perfectly.
The other wrecker says he will take back the TCCM from the Rainier no problem.
So now I have to figure out how to get the drivers side mirror out as I have no heat on that side.
Drivers side butt heater doesn't work but I don't care.
Thanks Roadie

 

[Woodsman]

Okay, so June 16 we have a huge torrential downpour and I drive through a big flooded section of road way.
A few minutes later the dash warning is on for the 4 WD and when I get home the selector is showing a range other than what it is in.
After all the usual things to try getting it working and getting inconsistent results I went to the scrap heap and got the old transfer case motor and put it back together and installed it.
So now it still doesn't work but at least the results are consistent.
So I figure that since the motor is dead on the old one and seems to be good on the current one maybe I can bodge together a unit that works.
So I release the brake on the old one and try the motor, it's dead but the brake works.
Now I release the brake on the current one and the motor works but the brake doesn't.
Brain storm! I'll take the brake off the old one and and put it on the new one.
That works fine to a point. The drive gear came off the old one relatively easy but there's is no way it's coming off the new one, so I'll cut the gear and break it off, use the gear off the old one and all is well in the universe.
Now things go off the rail, I got the gear off the new one but guess what?, the motor shaft is ever so slightly different than the old motor so the gear from the old one won't fit.
At the speed of light the new motor crashes into the wall.
Picked up another new motor today and everything seems fine.
When I took the motor apart that I was trying to fix I found it had water in it so obviously the seals on the motor from the factory were not sealed and must have buggered the winding's in the magnet coil or shorted quickly.
With shipping a hundred fifty bucks vanished but i didn't want to screw around trying to get a refund or replacement from the eBay seller as I need this car fixed for the upcoming vacation in two weeks and I'm just happy it's going now.
Anyone want to know whats inside a transfer case shift motor or how to take it apart the wrong way, just drop me a line.