I had this problem with my 07 Chevrolet Trailblazer. Before you buy all sorts of replacement, check the connections first at the TCCM controler (the small box underneath your steering wheel) and make sure they are properly seated and pressed down on the connectors. You can use a zip tie to properly secure 3 connectors. I did this fix and the selector switch worked right away. Thank me later.
the 2002's have a known issue with the TCCM computer. In our case it was a damaged wire on the harness that caused the TCCM to think the actuator wasn't working.
I have an 06. Replaced front axle actuator, switch works fine, hear boises on transfer case and frint axle actuators...literally everything LOOKS fine and sounds fine. But front wheels dont get power. Auto4 will engage 4wd after slippage, but 4Hi and 4Lo are still just rears working. Up on a lift, grabbing a front tire and spinning it will make the other side turn the opposite direction. Any ideas?
Got a 2003 trailblazer same problem open the driver side door ,pop open the panel on the side pushed the wire connection on tight and fixed my problem.
The issue with this vehicle was the retun line from the front wheel actuator. the actuator was working fine, however the line carying the signal (voltage) back was piched resulting in the TCCM thinking the front wheel actuator was not engaged.
have a 2004 TB and the other day after temps got down to -35 below zero, the 4wd went out....light just blinks and only 2wd works....but at same time the heater and blower went out the radio went out and the brake and abs lights as well as the service 4wd light came on the dash. Checked all fuses and none are blown. what do you think it could be.??
My 2002 have the same problem but I did replace the switch and the tccm and nothing did work,my solution was replacing my transfer motor = 20 minutes job and fix it.
have a 2003TB and the other day after temps got down to -35 below zero, the 4wd went out....light just blinks and only 2wd works....but at same time the heater and blower went out the radio went out and the brake and abs lights as well as the service 4wd light came on the dash. Checked all fuses and none are blown. what do you think it could be.??
+mike bryant Yes, you are correct about this. If when putting in neutral, and you can "hear" the transfer case going into 4 wheel low. This tells you the actuator motor on the transfer case is working. But lights just blink and never lock in. This is a defective actuator switch that is located on the front differential, that needs replacement. Looks like a small square flat box. replace it, and it should work fine.
I have been having the same problem with my Trailblazer with the 4x4 not staying in and the lights taking forever to s lock into the one I select. I replaced the front actuator and it has NOT resolved my issue. Also you do not need to go into neutral in the transmission to shift into A4wd or 4 high , only if your going into 4 Low is that necessary.
Help I have a 04 gmc envoy every time it rains my service 4wd light comes on and the 4wd disengage any type of moisture and this happen when its bone dry out side it works fine
I'm no master mechanic..........but it seems to me like you make have a 4x4 motor out.. I have a gmc sonoma that the 4x4 acts wierd......still works in low but wont work in high unless i reset that tcm? like you said. I'm thinking that my motor is on the fritz but if you guys have any other ideas thats what im trying
Mine is doing this, about how much did it cost yo repair. And what was wrong with it. The mechanic I went to was apparently an idiot and dosent know what is causing it so he want to replace the switch. Which I want to be 100% sure it is the switch before I make a useless repair.
I got a 04 trailblazer when i turn it too 4LO is the light continuously supposed to blink or stay solid...it will go in 4 hi every time but just blinks in 4 LO
My 05 trailblazer was doing the same thing but I finally figured out what the problem was I made a video about the problem check it out at smokies discovery I just posted good luck
You don't need to be in Neutral unless witching to 4LO, so I don't know that your statement is accurate. I am having the same issues right now, however I can hear the 4WD engage AND I can feel an idle speed change (showing transmission is engaged).
I shift into a4wd or 4 hi at anything below 35mph mine just started saying service 4wd light but my 4wd lights by switch work fine and so is my 4wd so im lost as all i find have worse semtems
ok guys , I have the same trailblazer , sometimes the lights are completely gone , and sometimes the lights on the 4x4 selector switch blink and blink , what a do is this . I disconnect the 4x4 fuse , swicht is # 8 .. on your manual .. and I disconnect the lighter switch fuse , don't ask me why ...I don't know ... but I wait one minute or so .. connet it both again and it work ... just like that ... hope this works for you guys ...
Did this fix the problem permanently or does it reoccur? On mine it's stuck in 4wd low... When switched to anything else it just flashes and flashes and eventually just goes back to 4wd low light.
hi, it was a temporarily fix, had to buy a TCCM on ebay with the same codes, cost me 70 dollars and change it myself, I take just 20 minutes. to change it. I saved $ 600 .. my mechanic try to charge that much for a 20 minute , the TCCM is located under the steering wheel on the left side is very simple change, I have not had any problems since then ...all system works now.... goog luck!!!!
I had this problem with my 07 Chevrolet Trailblazer. Before you buy all sorts of replacement, check the connections first at the TCCM controler (the small box underneath your steering wheel) and make sure they are properly seated and pressed down on the connectors. You can use a zip tie to properly secure 3 connectors. I did this fix and the selector switch worked right away. Thank me later.
Thank you so much for this tip, it worked great ! And I was worried about a large repair bill.
Ur da man. Gonna try n update
Great comment, you need a channel! Saved the day for me!
Thanks so much man! I just reached in and unplugged and plugged back in the first two blue connectors. Blinking light solved!
Thank you so very much. You have no idea how exited I was when I finally was able to switch from 4Lo to 2HI.
Why?
What was a your fix
TCCM replaced which helped, still having odd issues including the lights not coming on at all once so we also replaced the switch.
the 2002's have a known issue with the TCCM computer. In our case it was a damaged wire on the harness that caused the TCCM to think the actuator wasn't working.
blurryride
thanks
blurryride how did you fix that bad wire?
Thank you very musch, this video fix it my problem. thanks again.
I have an 06. Replaced front axle actuator, switch works fine, hear boises on transfer case and frint axle actuators...literally everything LOOKS fine and sounds fine. But front wheels dont get power. Auto4 will engage 4wd after slippage, but 4Hi and 4Lo are still just rears working. Up on a lift, grabbing a front tire and spinning it will make the other side turn the opposite direction. Any ideas?
Got a 2003 trailblazer same problem open the driver side door ,pop open the panel on the side pushed the wire connection on tight and fixed my problem.
good, this is an electrical or mechanical problem? and how I can fix it ?. because I have the same problem but with 4lo
nadim hage you don’t need four low unless you a super sticks it’s bad for ur vehicle but to engage 4low put it in nuetral first
The issue with this vehicle was the retun line from the front wheel actuator. the actuator was working fine, however the line carying the signal (voltage) back was piched resulting in the TCCM thinking the front wheel actuator was not engaged.
@hipoint45 replaced TCCM and then the front actuator. all is well now. not sure if it was both at faul, regardless for now its working :)
Please it happened the same video in my car is normal or when i switch to 4wd the lighg of 2wheel should stop .i have no idea since is my new car
google "trailblazer reading tccm codes" to see a writeup on how to read the codes
have a 2004 TB and the other day after temps got down to -35 below zero, the 4wd went out....light just blinks and only 2wd works....but at same time the heater and blower went out the radio went out and the brake and abs lights as well as the service 4wd light came on the dash. Checked all fuses and none are blown. what do you think it could be.??
I have a 2002 trailblazer
One day I started it and there was the red N, what does it mean
My 2002 have the same problem but I did replace the switch and the tccm and nothing did work,my solution was replacing my transfer motor = 20 minutes job and fix it.
have a 2003TB and the other day after temps got down to -35 below zero, the 4wd went out....light just blinks and only 2wd works....but at same time the heater and blower went out the radio went out and the brake and abs lights as well as the service 4wd light came on the dash. Checked all fuses and none are blown. what do you think it could be.??
Were you able to get it fixed? What was the issue?
Check your ignition switch. That was some of the issues I had and it was around a$30 part.
definitely the 4x4 actuator on the transfer case
+mike bryant Yes, you are correct about this. If when putting in neutral, and you can "hear" the transfer case going into 4 wheel low. This tells you the actuator motor on the transfer case is working. But lights just blink and never lock in. This is a defective actuator switch that is located on the front differential, that needs replacement. Looks like a small square flat box. replace it, and it should work fine.
I have been having the same problem with my Trailblazer with the 4x4 not staying in and the lights taking forever to s lock into the one I select. I replaced the front actuator and it has NOT resolved my issue. Also you do not need to go into neutral in the transmission to shift into A4wd or 4 high , only if your going into 4 Low is that necessary.
Me vale
@@angeldaniel7390 vete a la
Some times you need back up and go forward and it will go in 4x4
Thank you I was trying my switches and got stuck
Has to be in neutral
Both of light 2wd and the 4wl hi turned on when in switch from 2 to 4wd its normal
Help I have a 04 gmc envoy every time it rains my service 4wd light comes on and the 4wd disengage any type of moisture and this happen when its bone dry out side it works fine
I'm no master mechanic..........but it seems to me like you make have a 4x4 motor out..
I have a gmc sonoma that the 4x4 acts wierd......still works in low but wont work in high unless i reset that tcm? like you said. I'm thinking that my motor is on the fritz but if you guys have any other ideas thats what im trying
Put it in neutral then change it.
did you ever find a fix to this problem? I have an '02 envoy doing the exact same thing.
I was told it would do that if the fluid was low... other wish it might be the actuator.. check that first both are easy to do or replace..
none of our lights come on did you ever fix yours got any tips for me to try?
Mine is doing this, about how much did it cost yo repair. And what was wrong with it. The mechanic I went to was apparently an idiot and dosent know what is causing it so he want to replace the switch. Which I want to be 100% sure it is the switch before I make a useless repair.
Cv axle or axles are broke
I got a 04 trailblazer when i turn it too 4LO is the light continuously supposed to blink or stay solid...it will go in 4 hi every time but just blinks in 4 LO
Are u in neutral?
When I had this problem it was just a fuse under back seats
which ones?
My 05 trailblazer was doing the same thing but I finally figured out what the problem was I made a video about the problem check it out at smokies discovery I just posted good luck
There is nothing wrong with it. You have to be in neutral for it to engage. its blinking to say "I am waiting for you to put it into neutral"
Jacob Earl ... yes i did what you said about putting it into neutral and it works perfect nothing wrong i see
thanks soooo much just saved me 70$.
You don't need to be in Neutral unless witching to 4LO, so I don't know that your statement is accurate. I am having the same issues right now, however I can hear the 4WD engage AND I can feel an idle speed change (showing transmission is engaged).
It works for me too. I always engage in neutral
Not true. Only need neutral to go into 4 low.
I don't even have lights that come on , where is that fuse located at ? If you don't mind helping me
David Nuncio same here
Underneath the hood, driver side fuse box number 8
I shift into a4wd or 4 hi at anything below 35mph mine just started saying service 4wd light but my 4wd lights by switch work fine and so is my 4wd so im lost as all i find have worse semtems
You should never switch it into 4x4 unless the vehicle is stopped with the wheels straight... that probably messed it up
Messed mines up 🤦♂️
i have the same problem on my gmc envoy no light at all so i dont even know if the 4wd is working.....
SuperJoelness same here lol
It's probably the do l control box under the steering wheel.
Can you transfer from 4wd to 2wd while driving ?
Yes. You need to be in neutral though to go into 4 low and best do it with the vehicle stopped.
@adamv4951 actually it says in the owners manual that it is best to be rolling 1-2mph in neutral when engaging 4Lo.
Did you figure out the problem mine started this today in the middle of a winter storm -_-
Blurryride can you contact me my friend has trouble with his trailblazer
Put it in neutral then do it
I have same problem
How do u fix at
Trailblazer DVD radio repair DVD radio
like all 4wheelers know u gotta put it in neutral first then shift it into 4awd or 4hi or 4lo
no starit
ok guys , I have the same trailblazer , sometimes the lights are completely gone , and sometimes the lights on the 4x4 selector switch blink and blink , what a do is this . I disconnect the 4x4 fuse , swicht is # 8 .. on your manual .. and I disconnect the lighter switch fuse , don't ask me why ...I don't know ... but I wait one minute or so .. connet it both again and it work ... just like that ... hope this works for you guys ...
Did this fix the problem permanently or does it reoccur? On mine it's stuck in 4wd low... When switched to anything else it just flashes and flashes and eventually just goes back to 4wd low light.
hi, it was a temporarily fix, had to buy a TCCM on ebay with the same codes, cost me 70 dollars and change it myself, I take just 20 minutes. to change it. I saved $ 600 .. my mechanic try to charge that much for a 20 minute , the TCCM is located under the steering wheel on the left side is very simple change, I have not had any problems since then ...all system works now.... goog luck!!!!