[Tailblazer2006]

Great site! Anyway I have read through all the forums and can't quite get the answer I'm looking for. I have a 2006 trailblazer with the 4x4 service light on and no lights on the selector switch (they light up on start up so they work) and of course no 4 wheel drive. I turn the selector switch on and off 2 and 4 wheel with no lights and no engaging noises or sounds. I have jacked the front tires up and turned the tires and the shaft doesn't turn, I have taking the actuator off and had someone turn the selector switch on and off while running and the actuator is not going in and out but there is power going to it as I tested it. I took it to a mechanic and put a code reader on it and it said no code faults which confused him as the 4x4 light is on. I have also taken the fuse out for a bit and back in with no fix. So basically wondering if its the selector switch or the actuator or something else. Thanks

 

[Royalwapiti]

Mine started doing the exact same thing yesterday. At first it was just the 4x4 service light that came on. The selector switch light was on. It would would not disengage from 4 HI while driving. I stopped, shut the vehicle off, turned the selector to 2HI and restarted the vehicle. It was in 2 hi and the operating fine after that on dry pavement.

This morning wife started it, put it in 4 HI for the 2 miles of icy gravel out to the highway and the 4x4 service light came on. While on the fly she tried disengaging 4 HI and putting back into 2HI - no go. She shut the vehicle off put it in 2 HI and restarted the vehicle - Service Light still on and no Selector switch light is on.

Sounds like same issue.

 

[Envoyguy05]

sounds like your TCCM is in sleep mode needs to be replaced and reprogammed

 

[Royalwapiti]

I wonder if me installing a new battery last week has anything to do with it. I know it can play hell with the HVAC control actuators and other stuff...

Pulling the fuse for 30 seconds did nothing.

 

[Royalwapiti]

I replaced the TCCM with one from a salvage yard. It too was an 06 Trailblazer. It made no difference. 4x4 service light is on and the switch lights are OFF. And it doesn't go into 4x4.

I installed a new switch(From NAPA). It made no difference. 4x4 service light is on and the switch lights are OFF. And it doesn't go into 4x4.

The #8 fuse under the hood is intact.

Any other things to look at? Is there anyway to test the TCCM to see if it is good?

I suspect this came about due to a battery change about a week before problems started.

 

[poolmaster79]

I am having the exact same problems with my '04 Trailblazer.

 

[nickcindy419]

TCCM and replaced the dash switch still issues

I have the same thing going on bought the tccm from motion and was supposed to come preflashed for my vehicle, no luck so we bought a new control knob for the dash still nothing any ideas?

 

[Royalwapiti]

Either of you have any luck?

So far I tried:

Used TCCM - no difference

Brand New Switch - no difference

Used Encoder Motor - no difference Although the service light went off and the switch led came on....until I tried putting it into 4HI, it wouldn't go and i turned the vehicle off and restarted it. The switch led went off and the service light came back on. back where I started.

Auto mechanic tested it today and said Code C0327 Encoder Circuit

He said he usually puts a new one on and the problem goes away when he gets that code.


Any of you get it fixed yet?

 

[cmane419]

I'm having this issue right now after just having a tranny put in now I have no lights on switch and no service 4x4 light on dash when I turn my key on....

 

[Royalwapiti]

I'm having this issue right now after just having a tranny put in now I have no lights on switch and no service 4x4 light on dash when I turn my key on....

One thing I learned was that when the Transfer Case Control Module attempts to put the transfer case in to 4Hi or whatever, it gives it one chance and if it fails for whatever reason, it turns the service light on and kills the power to the switch.

My problems ended up being the transfer case. I took mine to a dealer and paid $200 for them to tell me the transfer case was bad. They spent 3 hours troubleshooting it. I then put a salvage yard transfer case on myself, problem fixed.

The dealer tested all circuits etc and then opened the case and said he smelled burned fluid. Something in it got hot.

Good luck. The dealer diagnosing it was worthwhile for me. A hassle but worthwhile, I took it to a dealer 30 miles away, I drove past 2 other dealers on my way there. One is lousy and the other I know nothing about.

I have a few of the connector pigtails for the speed sensors if you by chance forget to unhook one when you drop the TCase...duh my bad

 

[cmane419]

Mine acts as if it has no power to it no noise when moving switch no 4x4 light no light above switch it worked when I dropped it off at the shop now nothing.

 

[jacobrb]

I've had a module, switch, and a actuator replaced. $1000 later the switch still switches, shifts are still heard and made, and lights function properly. Still I get ONE wheel drive in 4lo. Explain that!!! See if any you smart guys on here are really as smart as you lead everyone on here to believe.