4-Wheel Drive not working

Old 04-25-07, 06:06 AM
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4-Wheel Drive not working

I have a Chevy Trailblazer (2002) All of a sudden the 4-wheel drive isnt working. I turn the knob on the dash and nothing happens. No lights, no nothing.

I checked the fuse and it is fine. I changed it anyways and it didnt work.

Anyone have any ideas?

Old 04-25-07, 06:29 AM
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Welcome to the diy forums!

I'm not familiar with your 4x4 [or any that utilize a switch] but I'd check the switch and it's wiring.

Old 04-25-07, 07:21 AM
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i don't know if you're truck has the same system as the 02 S10 or not.
see if you can find GM document # 642932 on clearing the DTC. had to do mine twice. it's a bit long to type out here so if you can't find it let me know.
Old 04-25-07, 08:08 AM
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A friend has the same vehicle only 2 yrs newer.

They've had the 4WD go out 2 times now both times different parts that run ~$500 to fix, they said the dealer wasn' suprised and the problems where pretty common. Now theirs works well when it's nice out but if it's cold out the thermal acuator doesn't always work so 4WD is essentially out a 3rd time. Dealer wants another $400 to fix that. They've decided to sell it this fall while it's still warm enough to work.

Sorry I can't offer any DIY help for it but I'm guessing if you talk to your dealer they'll have a couple common options to suggest.
Old 04-25-07, 06:56 PM
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4 wd

I would check the vacuum tubing to make sure it is connected and in good shape. Easiest fix I ever did is when my blazer's 4wd stopped working, opened hood and plugged in a vacuum tube that had worked loose.
Old 04-30-07, 06:44 PM
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there is no thermal actuator and no vacuum lines to this system it is all electric and you have already replaced the switch now comes the bad part take it to a dealer and have them clear the codes and reprogram the 4wd controll module there have been several updates for your system and should take care of the problem and be very specific to the dealer about what you want and what you have done so they do not charge you for stuff that has alredy been done

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