Hey everyone. I need some help since my 06 trailblazer ext's t-case is stuck in neutral. The transmission is in park and I can push the truck back and forth with no problem. The 2wd light on the selector switch is on and the service 4x4 light is on as well. My encoder motor is new and I do not feel like taking the encoder motor off again. It was a battle to get it back on the second time. I have a new TCCM and would like to know if I should unplug the battery and pull the #8 fuse or what? Any help would be great. I need to get this truck back on the road. Thanks in advance.
NEED HELP Transfer case issues
- Thread starter matty8412
- Start date
Mooseman
Moderator
Getting the encoder motor on should not be a battle at all. Sounds like your TC is either stuck or damaged. This is more possible if it wasn't maintained properly with a fluid change every 50k miles. To diagnose further, you will have to pull the encoder and try to move the shaft manually with pliers or vice-grips. If it won't move, I would assume the TC is done.
I was able to manually shift the tcase from 2wd to 4hi. Then when I plugged the encoder motor and turned the key and switched the selector switch from 2hi to 4hi but it went to N. The selector switch was reading 2wd but I think it was actually in 4hi and when I turned the nob to 4hi it went into neutral. I've changed the fluids in the entire truck frequently and never seen traces of worn down gears and such.
Mooseman
Moderator
Mooseman
Moderator
I'd be inclined to find a shop that could read the code from the TCCM. It could give a clue as to what is going on. What about the switch? Have you tried replacing it?
If you pull the encoder and still have it connected, does it move if you move the selector switch? Light still come on?
No reset is necessary with the TCCM. It basically resets itself each time the truck is shut off.
If you pull the encoder and still have it connected, does it move if you move the selector switch? Light still come on?
No reset is necessary with the TCCM. It basically resets itself each time the truck is shut off.
My wife's friend is a heavy duty mechanic and has a scanner. He will try to come out and take a look at it as well . The first time we changed the encoder motor we plugged it in but had if not connected to the tcase. My father in law turned the switch to 4hi and it turned but then stopped and the switch lights went out and the service 4x light came on. I will wait and see when the mechanic comes over this weekend. If we figure it out I will let you know. Thanks Mooseman
Mooseman
Moderator
Could also be a wiring issue if one of the sensor wires from the encoder is broken and not reporting back to the TCCM its current position.
So I should first check to see if the wires are ok before assuming that it's the tcase? I'm just annoyed since the last time I changed the oil last month in the tcase and everything was working properly until 3 weeks ago and now it's just getting worse. This truck is in such awesome shape and so clean.
Might have a read through here....
With a new encoder motor and continued trouble I would look at wiring connectors and the selector switch in the dash. Not just visually but with a meter or scanner.
TSB 3061F Archives
ricksfreeautorepairadvice.com
Might have a read through here....
With a new encoder motor and continued trouble I would look at wiring connectors and the selector switch in the dash. Not just visually but with a meter or scanner.TSB 3061F Archives
ricksfreeautorepairadvice.com
Yep that's what I will be doing today.
Mooseman
Moderator
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gmtnation.com
Hey there mooseman. I need your advice here. So my trailblazer is still not driving properly. I have replaced the encoder motor, swapped tccm, tested the wire harness from encoder motor to the under hood fuse box and all checks out good. The front axle actuator functions as well. I went and started it yesterday after troubleshooting. And the service 4x4 cluster light went out and had the proper selector switch light on. Had my father in law checking for the encoder motor functions as I turned the switch which functioned properly on the switch and the selector switch. But then once I got to switching it from a4wd to 4hi it quit. Lights on the switch went all out and the service 4x4 light came back on.
The other thing is that when I put the transmission in drive, the truck seems to bind one way and then binds the other way in reverse. Plus the transmission wont shift anywhere from 1st gear. Please tell me if you know what is causing this major issue. This is taking a toll on me. I just dont want to keep throwing money at it when I have no clue what to change out. Thank you in advance.
Mooseman
Moderator
While checking the encoder motor operation, was it removed from the TC to watch it move? Are you able to move the shaft on the TC with pliers? If it won't move, the TC might be damaged and won't shift into 4hi.
When you put it in A4WD, all it does then is lock the disconnect. It's only when a rear wheel slips the TC will engage.
When you put it in A4WD, all it does then is lock the disconnect. It's only when a rear wheel slips the TC will engage.
So. The encoder motor was on the t-case. And we were able to hear the whirling noise as when the truck worked properly. And yes we are able to turn the t-case shaft with a wrench. This is the third brand new encoder motor. Acdelco brand too. I highly doubt that it's the encoder motor. Would the selector switch be a problem perhaps? This is frustrating. Or am I looking at something that may be up with the transmission? I have all the wiring schematics that I need due to yourself and other members on this great forum. How can I test the wiring on the selector switch? I'm just really frustrated that the truck was driving fine until the service 4x4 light came on. Then brought it to get scanned and came back the encoder motor was toast. So simply replaced with a new one and now it dont work at all.
well, the motor making noise is only ONE of the circuits. The controller needs to know where the motor is in its position. As many have suggested, you need to check the electrical characteristic of the circuits / wires at the encoder. They are "new motors" so it is unlikely that your problem is an encoder problem although breaking one is a possibility if you run them disconnected as there is nothing in its guts to stop the encoder from going too far (iirc).
As for the "scan it and came back with encoder motor was toast" sounds pretty fishy to me.... but the world has lots of scammm ... scanners
As for the "scan it and came back with encoder motor was toast" sounds pretty fishy to me.... but the world has lots of scammm ... scanners
Budwich, the scanner came back with the code c0327 when scanned the very first time and the message was encoder motor not recognized.
Mooseman
Moderator
C0327 is an Encoder Motor circuit malfunction. Did you check continuity from the encoder to the TÇCM?
Do you have any of the old ones? Maybe just try to plug them in to see what happens. You might have gotten a bum encoder.
Do you have any of the old ones? Maybe just try to plug them in to see what happens. You might have gotten a bum encoder.
We checked the continuity from the encoder to the tccm yes. Everything checked out good. And this is the 3rd brand new encoder motor straight out of the box. I understand that it is possible to buy a new encoder and it be faulty to begin with but after 3 brand new ones?
Mooseman
Moderator
The first one came back C0306. Which if I remember correctly it means a short to ground circuit A/B . So I returned that one and they ordered me a new one. Came home to opening up the box and finding a newish encoder with 4 used encoder bolts. And the plastic tool that comes inserted in the cog that's tabs onto the tcase shaft itself was not there. So I returned that one. Ordered another brand new one that came with the plastic and was properly clocked. This is the one that I have on presently. Now I just have to wait for my friend with the scanner to come back hopefully tomorrow and scan it.
you keep waiting for a "magic scanner bullet"... it is unlikely to happen. I keep telling you to get a meter and do some voltage and resistance measurements at the connector. You are likely to find that you have little or none where you should. The thing only has 6 wires which involves 3 circuits... a motor drive, a position sensor and a "lock mechanism". Since you "appear" to indicate that your hear the motor, that leaves the position sensor circuit as the only one that you need to check. I do believe I have told you that in another thread. Anyway, good luck, I hope that you find the issue.
Additionally, doing continuity on a disconnected cable only tells you that the copper between the connectors "may be OK" depending on how you actually carried out the test... it doesn't tell you that it can complete a connection thru the connector to something on the other end ... why... because the making of the connector may have an issue such that electrically, it does not allow the completed circuit to work.
You likely have further problems with the state of the drive train... since you indicate that you can't move forward or backward... at the present time???? IF you lift both front wheels off the ground, you are saying neither can be turned by hand. :-(((((
Additionally, doing continuity on a disconnected cable only tells you that the copper between the connectors "may be OK" depending on how you actually carried out the test... it doesn't tell you that it can complete a connection thru the connector to something on the other end ... why... because the making of the connector may have an issue such that electrically, it does not allow the completed circuit to work.
You likely have further problems with the state of the drive train... since you indicate that you can't move forward or backward... at the present time???? IF you lift both front wheels off the ground, you are saying neither can be turned by hand. :-(((((
Just to update. My TB is now fixed. Turned out that my tcase was the culprit. The tcase was stuck in low range and wouldn't move. Thanks to all who have tried helping me narrow down the search. Much appreciated
So although you could move the shaft manually, it wasn't shifting and stayed in low?
Did you replace or repair the tcase?
Did you replace or repair the tcase?
I will eventually open up my old damaged t case and see what exactly the problem was. If I find the culprit and if it wont cost too much I might just buy the parts and rebuild it so I'd have a back up t case