Warning:
- Driving in 4WD mode on smooth, dry, paved roads for extended periods of time may shorten the life of your vehicle's transmission.
- Driving for long periods of time with automatic connection of all-wheel drive or all-wheel drive with an elevated transfer case stage enabled may reduce the service life of the transfer case and/or the all-wheel drive system.
- Use the all-wheel drive system only when additional traction is needed, such as on wet or icy roads.
- Under normal driving conditions, set the transfer case switch to rear-wheel drive only.
Automatic transfer case
1. The automatic transfer case switch is located on the control panel (see illustration). You can choose one of four transfer case operating modes.
10.1 Automatic Transfer Case Switch
Rear wheel drive A
2. The switch should be in this position under normal driving conditions in the city and on highways. In this mode, your vehicle's front wheels are disconnected from the engine. This mode provides the best fuel economy.
Automatic all-wheel drive activation B
3. This is the best mode for driving in changing road conditions. The front drive axle is connected, but all torque is directed to the rear wheels. Only when the system detects rear wheel slip does all-wheel drive automatically engage. Driving in this mode results in slightly reduced fuel economy compared to driving in 2WD mode.
All-wheel drive with high-ratio transfer case C
4. In this mode, the front drive axle is constantly engaged. Use 4HI mode in conditions where extra traction is needed, such as on wet or icy roads, or when driving off-road.
All-wheel drive with low-range transfer case D
5. In this mode, the front drive axle is also constantly connected to create additional traction force. This mode should only be used in severe off-road conditions, when driving in deep sand, mud, or on steep ascents and descents.
Neutral E
6. Use this transfer case mode only when towing your vehicle.
Warning: If neutral is turned on in the transfer case, your car may roll even if the automatic transmission selector is in the P (Parking) position. You or other people may be seriously injured. Make sure the parking brake is set before shifting the transfer case into neutral.
7. When the ignition is turned on, all indicators located around the transfer case operating mode switch will light up for a short time, and then the indicator corresponding to the mode turned on in the transfer case will remain lit. If these indicators do not light up when the ignition is turned on, you must contact a service station. Turn the switch to the position corresponding to the desired transfer case operating mode.
8. During the switching process, the indicator will flash and when the switching is complete, it will light up continuously.
9. If the transfer case cannot perform the required shift, it will return to its previous mode.
10. If a malfunction of the all-wheel drive system occurs, the all-wheel drive system malfunction indicator will light up on the instrument panel.
11. To engage or disengage the all-wheel drive mode with a low gear, the ignition must be on, the car must be stationary or moving at a speed of no more than 3.2 km/h (it is preferable that it moves at a speed of 1 to 3 km/h), and the automatic transmission selector must be in position N (Neutral).
12. Turn the switch to the position corresponding to the desired transfer case operating mode. During the switching process, the indicator will flash and when the switching is complete, it will light up continuously.
13. If you attempt to engage or disengage the 4WD Low range mode while the transmission is in a drive gear and/or the vehicle is moving too fast, the indicator will flash for 30 seconds and the shift will not be performed until the vehicle speed is reduced to less than 3 km/h and the automatic transmission is in N (neutral).
14. If the transfer case cannot perform the required shift within 30 seconds, it will return to its previous mode.
15. To shift the transfer case into N (Neutral) mode for towing the vehicle:
a) Park the vehicle so that it cannot roll, apply the parking brake and start the engine.
b) Move the automatic transmission selector lever to position N (Neutral).
c) Engage the transfer case in rear wheel drive mode.
d) Turn the transfer case switch so that it passes through the low range 4WD position and hold it in this position for at least ten seconds. When the transfer case is in neutral, the transfer case neutral indicator will come on.
e) Move the automatic transmission selector lever to position R (Reverse) for one second, then move it to position D (Moving forward) also for one second.
f) Turn the key to the auxiliary power position.
g) Move the automatic transmission selector lever to position P (Park).
h) Turn the ignition key to the LOCK position (Blocking).
16. To shift the transfer case from N (Neutral) mode:
a) Apply the parking brake lever and press the service brake pedal.
b) Turn on the ignition, but do not start the engine.
c) Move the automatic transmission selector lever to position N (Neutral).
d) Turn the switch to the position corresponding to the desired transfer case operating mode.
When the transfer case shifts out of neutral, the transfer case neutral indicator will go out.
e) Release the parking brake lever.
f) Start the engine and move the automatic transmission selector lever to the required position.
About this guide
Purpose
The goal of the creators of the manual is to help the owner to operate and maintain the car in the most rational way. Using this book will help you determine what work needs to be done (even if it is produced at a service station), will provide information on current maintenance and will allow you to determine the cause of the malfunction. We hope that this guide will be used when performing repairs and maintenance on your own. Sometimes (in relatively simple cases) doing the work yourself may be faster than going to a service station, considering that you will have to go there twice - to leave and then pick up the car. It is important to note that you can save money if you do the work yourself. In addition to the above factors, a car enthusiast can experience a sense of moral satisfaction by independently performing maintenance and repairs on his own car.
Structure
The guide is divided into chapters. Each chapter consists of subsections, the titles of which are numbered and highlighted. Each subsection consists of numbered points.
At the beginning of each subsection there are references to illustrations that supplement the description of the procedures. The numbers of the illustrations identify the subsection and the corresponding item. For example, Illustration 3.2 corresponds to the second point of the third subsection.
Procedures previously described in the text are generally not described again. If it is necessary to refer to another chapter, a reference is provided indicating its number and the number of the corresponding subsection. References given without the word "chapter" refer to subsections and/or paragraphs of that chapter. For example, "see subsection 8" refers to the eighth subsection of that chapter.
References to the left and right sides of the vehicle are as viewed from the driver's seat.
Despite the care taken in preparing this guide, the author and publishers assume no responsibility for any inaccuracies or omissions that may appear in this book.
Note: This note contains information that is necessary to properly complete or better understand the procedure.
Caution: The information contained in a caution pertains to a special operation or action that is necessary for the proper completion of the procedure described. Failure to follow the warning may result in damage to the component or part being worked on.
Warning: The information contained in a warning pertains to an operation or action that is necessary for the proper completion of the procedure described. Failure to follow the warning instructions may result in injury or bodily harm.
Brief description of Chevrolet TrailBlazer, Oldsmobile Bravada and GMS Envoy
The Chevrolet Trailblazer, Oldsmobile Bravada and GMS Envoy SUVs discussed in this guide were launched in 2002. The vehicles are available in two-wheel drive, four-wheel drive and standard (5 passenger seats) and elongated (7 passenger seats) base. The models described are equipped with a 4.2-liter in-line six-cylinder engine and an automatic six-speed gearbox with an "overdrive" mode.
The chassis has a classic layout: through an automatic transmission, torque is transmitted to the rear wheels from the front engine. In all-wheel drive versions, engine power is transmitted not only to the rear wheel, but also to the front differential, from where the torque is transmitted to the front wheels via independent drive shafts.
The design of the front independent suspension uses struts consisting of shock absorbers and springs. The one-piece rear axle has four longitudinal arms, a transverse reaction rod, springs and shock absorbers.
The steering has a power steering and a rack and pinion gear, which is attached to the frame behind the front wheels. The design of the brake system with a vacuum booster, having an ABS function, provides for the presence of disc front and rear brakes.