Why won't 2003 Trailblazer come out of 4 low

Hi Carmelo:
The answer should be yes. even the drive shaft to the front will turn. The front drive will be engaged in the transfer case when in 4 wheel drive, but not when in 2 wheel drive.

Vehicles: 2002 Chevrolet Trailblazer 4WD 4.2L SFI DOHC 6-cylinder

Your front 4WD Transfer case is low on Gear Oil.
On warm days, the Gear Oil expands slightly, and is less viscous, so the "Service 4WD" light stays off. On colder days/mornings the story changes.

The following paragraph has info applying to the manual differential only:
The 2002 Trailblazer (the first year Chevy made the Trailblazer) has a Front Differential using 1.11 (that's 1 and 1/9th) Quarts Gear Oil, and a Rear Differential with a capacity of 2.29 (thats 2 and 2/7ths) Quarts Gear Oil.
The Gear Oil needed is GM Part No.12345349 or GM Part No.1052931 (they're identical), also known as "GM Synchromesh"(R), which is a type of GLS (Gear Lubricant, Special), also known as "Manual Synchromesh Transmission Fluid 5W30". A synthetic version of which sells for $12.70/qt (USD) at
http://www.amsoil.com/storefront/mtf.aspx

This is not to be confused with 5W30 motor oil (which can be had for $3.00/qt (USD)).

The 2002 Trailblazer 4WD Transfer Case (NV126 Transfer Case) capacity is 0.8 Liters of GM Part No.12378508 (US), also known as "GM Auto Trak II"(R).
Note that one Quart (US) = 0.946 Liter, so 0.8 Liter = 27.06 ounces.

Red Line sells something that they say replaces both GM Synchromesh and GM Auto-Trak II for $12.14/Qt and $44.55/Gal (US) at
http://www.shopwiki.com/Red-Line-MTL-70W80-GL~4-Gear-Oil-%281-Quart%29

13 Manufacturer Recalls apply to the 2002 Chevrolet Trailblazer (model year 2002 was the first year Chevy offered the Trailblazer), and two recalls pertain to the 4WD Transfer Case. Note that one of the recalls applies to only 895 units, so your vehicle is unlikely to be affected by this Transfer Case recall.

2002 Trailblazer Recall ==========================
OCT 17, 2001 ' Recall ID# 54221

Recall Reason POWER TRAIN:TRANSFER CASE (4-WHEEL DRIVE)
Recall Date OCT 17, 2001
Model Affected TRAILBLAZER
Potential Units Affected 78004

Recall Summary
VEHICLE DESCRIPTION: SPORT UTILITY VEHICLES EQUIPPED WITH 4-WHEEL DRIVE. THE CALIBRATION OF THE TRANSFER CASE CONTROL MODULE COULD CAUSE INSUFFICIENT HIGH SPEED GEAR ENGAGEMENT.

Consequence
IF THE GEAR IS NOT ENGAGED, THE VEHICLE CAN ROLL WHEN THE TRANSMISSION IS IN "PARK" AND A CRASH COULD RESULT WITHOUT WARNING.

Remedy
DEALERS WILL UPDATE THE TRANSFER CASE CONTROL MODULE CALIBRATION TO INCREASE GEAR ENGAGEMENT. OWNER NOTIFICATION BEGAN NOVEMBER 6, 2001. OWNERS WHO TAKE THEIR VEHICLES TO AN AUTHORIZED DEALER ON AN AGREED UPON SERVICE DATE AND DO NOT RECEIVE THE FREE REMEDY WITHIN A REASONABLE TIME SHOULD CONTACT CHEVROLET AT 1-800-222-1020 OR GMC AT 1-800-462-8782.

Notes
GENERAL MOTORS CORP. 01064/01065

2002 Trailblazer Recall ============================
SEP 05, 2001 ' Recall ID# 26006

Recall Reason POWER TRAIN:TRANSFER CASE (4-WHEEL DRIVE)
Recall Date SEP 05, 2001
Model Affected TRAILBLAZER
Potential Units Affected 895

Recall Summary
VEHICLE DESCRIPTION: SPORT UTILITY VEHICLES (4 WHEEL-DRIVE). SOME OF THESE VEHICLES WERE BUILT WITH A RANGE SHIFT COLLAR IN THE TRANSMISSION TRANSFER CASE THAT CONTAINS CRACKS.

Consequence
THIS CONDITION COULD RESULT IN A COMPLETE FRACTURE OF THE RANGE SHIFT COLLAR AND SUBSEQUENT LOSS OF VEHICLE FORWARD AND REVERSE GEARS, AND THE INABILITY TO MAINTAIN "PARK" POSITION. THIS INCREASES THE RISK OF A VEHICLE CRASH RESULTING FROM UNINTENDED MOVEMENT OF A PARKED VEHICLE.

Remedy
DEALERS WILL REPLACE THE TRANSFER CASES AND UPDATE THE CONTROL MODULE CALIBRATION. OWNER NOTIFICATION BEGAN SEPTEMBER 6, 2001. OWNERS WHO TAKE THEIR VEHICLES TO AN AUTHORIZED DEALER ON AN AGREED UPON SERVICE DATE AND DO NOT RECEIVE THE FREE REMEDY WITHIN A REASONABLE TIME SHOULD CONTACT CHEVROLET AT 1-800-222-1020 OR GMC AT 1-800-462-8782.

Notes
GENERAL MOTORS CORP. 01061


Read about all (13) 2002 Chevy Trailblazer recalls at:
http://www.internetautoguide.com/10-12-2002-16-1287/2002-chevrolet-trailblazer-recalls.html

When you switch from 2HI to 4HI, you should hear two distinctive sounds from under the truck, one is the transfer case actuator and the other is the front differential actuator. If you hear both and you still do not have power going to the front wheels, then there is a problem with the front disconnect assembly.

Depends, do you have 4 wheel drive? If so you can just use 4 wheel high, or if things get really slippery, use 4 wheel low and go slow, both in the drive position on the transmission shifter.

If 2wd, just use drive and go slow, again, if it gets slippery out, you can shift down in gears to go slower and to keep your speed slow.

If you're talking about snow and ice on just streets, then stick with 4 wheel high with 4x4, or "drive" in 2wd. You typically don't want to switch to 3,2, or 1st gear at highway speeds.

If you're playing in the snow, just use 4x4 high until you get stuck, then switch to 4 low to get out.

The only time I switch gears with the transmission (from drive to 3,2, or 1) is when I want to go really slow and keep it there. However, when I "play" in the snow, it's Drive only.

Does this answer your question? If not, let me know! Thanks

motor on transfer needs tested and replaced

usually the actuator will still make the light still come on if its bad I would check the actuator

On an 86 you probably still had the hub locks on the outside. You have to get down off the truck and manually turn the hubs to the lock position. The hubs are located in the middle of the wheel. Then Put the 4 wheel drive gear shift to 4 hi or 4 low. At the low level it runs very slowly and very low geared. At 4 hi, it runs normal but the 4 wheel drive engages. When you are not using the 4 wheel drive it is good that you get off the truck and turn the hubs counter clockwise to the off position.

check the lubricant in the transaxle, if it is low it will cause the light to come on.

That is up to your preference in my opinion. 4 wheel may give you a little more traction, but it can also lead you into a false sense of security. If heavy snow, and you need to get through it, you can only go as fast as the guy ahead of you anyway right? Up here in Ontario Canada, I passed by many a 4 wheel drive in the ditch, because they assumed they would have a better chance on icy roads than me, with 2 wheel drive. Remember this, no matter what you decide, you may be able to go a little faster in 4 wheel, compared to 2 wheel, but when you have to hit the brakes, or go into a spin, 2 wheel or 4 wheel drive, your not going to be able to stop it any faster. Your going to use more gas in 4 wheel too. Yes there will be times when you need to use it, but like I said, when it goes sideways or you have to lock up the brakes, because you were pushing the envelope too much,? At least with 2 wheel, you feel the back end break loose, to warn you how slippery it is, and you may not feel that soon enough, with 4 wheel. Just my opinion, but maybe some 4 wheelers have a different opinion. It's just like the experts from the skid school said up here about mandatory snow tires being talked about. If putting snow tires on your car is going to make you drive a little faster, your defeating the purpose.