How JustAnswer Works:

  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site.
    Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.

Ask Bob Your Own Question

Bob
Bob, Auto Tech
Category: Chevy
Satisfied Customers: 4087
Experience:  Plus 40 years GM, over 30 certified with Chevrolet, ASE certified Master Tech. (Expired, Retired)
2210118
Type Your Chevy Question Here...
Bob is online now
A new question is answered every 9 seconds

2002 chevy trailblazer ls: 4wd..the transfer case..next time..bucks

Customer Question

i have a 2002 chevy trailblazer ls 4wd, the indicator lights for the 4wd system do not come on , i have taken it in to find the problem before about a year ago and i was told that the transfer case did not get a "wake up " signale to wake up and had to be reset they said that next time this happens to read my manual to reset it my self , i cannot find the reset proceedure and i don't want to pay another 100 bucks if i can do it myself please help me thanks
Submitted: 6 years ago.
Category: Chevy
Expert:  Bob replied 6 years ago.

Hello, There is no actual reset procedure, I guess that is why you can't find it in the owners manual The actual reprograming on the unit is done with a class 2 scanner. The only thing you can try at home to reset the module is by removing the fuse under the hood. Look for a fuse labeled ATCM or TREC or TCCM. Once you have removed the fuse, wait 10 seconds and re install it. If this clears your condition, great. But, I have not seen it work very often. The correct way is to connect a class 2 scanner to the system and read any stored codes in the system and repair as needed. The codes will point you to the failed sensor or component. A regular code reader can't do this job as all they can read are codes related to the engine, emissions and transmission. This module is a class 2 electronic device so a class 2 scanner is the only thing that will interface with it. And the scanner is what is used to reprogram it. Below is another procedure that you may want to try and below that is what the factory says about it going to sleep. I hope some of this helps you. Thanks

Recommendation/Instructions:

The software in the transfer case control module has a "shift abuse lock out" mode to protect the module and encoder motor. This concern will occur if the module senses repeated shift request in a short period of time. If the driver continuously tries to shift in and out of different modes, the transfer case control module will stop trying to shift for several seconds to prevent abuse damage to occur. Cycling the ignition off for 30 seconds or more should allow the transfer case to resume normal operation.

Please follow this diagnostic or repair process thoroughly and complete each step. If the condition exhibited is resolved without completing every step, the remaining steps do not need to be performed.

 

  1. Document ID#(NNN) NNN-NNNN
    2002 Chevrolet TrailBlazer - 4WD

     

    Subject:Inoperative 4WD/AWD Lamps, Inoperative 4WD/AWD System, DTC C0550 Set No Communication with TCCM (Reprogram Transfer Case Control Module) #02-04-21-006E - (07/20/2006)

     

    Models:2004 Buick Rainier
    2002-2004 Chevrolet TrailBlazer, TrailBlazer EXT
    2003-2004 Chevrolet Avalanche, Silverado, Suburban, Tahoe
    2002-2004 GMC Envoy, Envoy XL
    2003-2004 GMC Sierra, Yukon, Yukon XL
    2004 GMC Envoy XUV
    2002-2004 Oldsmobile Bravada
    with Electronic Shift or Active Transfer Case (RPOs NP1, NP4 or NP8)

     


    This bulletin is being revised to add Subject information and change the labor operation. This bulletin cancels and supersedes Bulletin Number 03-04-21-006. Please discard Corporate Bulletin Numbers 02-04-21-006D and 03-04-21-006 (Section 04 -- Driveline/Axle).


    Condition

    Some customers may comment that the 4WD/AWD indicator lights on the selector switch do not work, or the 4WD/AWD system may be inoperative and/or the service 4WD light is illuminated. The condition is typically intermittent and always occurs at key-up. Upon investigation, the technician may find DTC C0550 set.

    Cause

    The Transfer Case Control Module (TCCM) has not received the wake-up call during key-up and has remained in the "sleep mode".

    When the TCCM is in the "sleep mode", it will not communicate with the class II bus or the Tech 2®.

    Correction

    1. Try to communicate with the TCCM. If no communication, go to step 2. If communication is possible, go to step 5.
    2. Remove the underhood (ATCM or TREC) TCCM fuse.
    3. Wait 30 seconds.
    4. Reinstall the fuse. The module should "wake up" and communicate with the Tech 2®.
    5. Check for codes in the TCCM. If a C0550 is found current or in history with or without other codes, replace the module and go to step 6.
    6. Reprogram the TCCM with the latest TIS software using normal SPS procedures.
    7. Verify operation and that no codes are present.

    Important: For the 2002 model year, the TCCM must be replaced and reprogrammed.

    Warranty Information

    For vehicles repaired under warranty, use:

    Labor Operation

    Description

    Labor Time

    K4121

    Transfer Case Module - Reprogram with SPS

    0.4 hr

     

    GM bulletins are intended for use by professional technicians, NOT a "do-it-yourselfer". They are written to inform these technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions, and know-how to do a job properly and safely. If a condition is described, DO NOT assume that the bulletin applies to your vehicle, or that your vehicle will have that condition. See your GM dealer for information on whether your vehicle may benefit from the information.
    WE SUPPORT VOLUNTARY TECHNICIAN CERTIFICATION

    © Copyright General Motors Corporation. All Rights Reserved.


    Document ID#(NNN) NNN-NNNN
    2002 Chevrolet TrailBlazer - 4WD

 

JustAnswer in the News:

 
 
 
Ask-a-doc Web sites: If you've got a quick question, you can try to get an answer from sites that say they have various specialists on hand to give quick answers... Justanswer.com.
JustAnswer.com...has seen a spike since October in legal questions from readers about layoffs, unemployment and severance.
Web sites like justanswer.com/legal
...leave nothing to chance.
Traffic on JustAnswer rose 14 percent...and had nearly 400,000 page views in 30 days...inquiries related to stress, high blood pressure, drinking and heart pain jumped 33 percent.
Tory Johnson, GMA Workplace Contributor, discusses work-from-home jobs, such as JustAnswer in which verified Experts answer people’s questions.
I will tell you that...the things you have to go through to be an Expert are quite rigorous.
 
 
 

What Customers are Saying:

 
 
 
  • I was having a terrible problem with the wheel bearings on my 98 Chevy Cavalier and I suspect that using this website saved me plenty of time and money. Todd L Rochester NY
< Last | Next >
  • I was having a terrible problem with the wheel bearings on my 98 Chevy Cavalier and I suspect that using this website saved me plenty of time and money. Todd L Rochester NY
  • Wonderful service, prompt, efficient, and accurate. Couldn't have asked for more. I cannot thank you enough for your help. Mary C. Freshfield, Liverpool, UK
  • This expert is wonderful. They truly know what they are talking about, and they actually care about you. They really helped put my nerves at ease. Thank you so much!!!! Alex Los Angeles, CA
  • Thank you for all your help. It is nice to know that this service is here for people like myself, who need answers fast and are not sure who to consult. GP Hesperia, CA
  • I couldn't be more satisfied! This is the site I will always come to when I need a second opinion. Justin Kernersville, NC
  • Just let me say that this encounter has been entirely professional and most helpful. I liked that I could ask additional questions and get answered in a very short turn around. Esther Woodstock, NY
  • Thank you so much for taking your time and knowledge to support my concerns. Not only did you answer my questions, you even took it a step further with replying with more pertinent information I needed to know. Robin Elkton, Maryland
 
 
 

Meet The Experts:

 
 
 
  • Tim's Auto Repair

    mechanic

    Satisfied Customers:

    7641
    Have owned a repair shop for 25 yrs.
< Last | Next >
  • http://ww2.justanswer.com/uploads/TI/tim37857/2011-10-28_23053_S6301814.64x64.JPG Tim's Auto Repair's Avatar

    Tim's Auto Repair

    mechanic

    Satisfied Customers:

    7641
    Have owned a repair shop for 25 yrs.
  • http://ww2.justanswer.com/uploads/DT/dt69nova/2012-6-15_234154_pic1.64x64.jpg Dave Nova's Avatar

    Dave Nova

    Chevrolet Technician

    Satisfied Customers:

    6870
    ASE Master Certification. GM World Class Certification
  • http://ww2.justanswer.com/uploads/ggrote1/2009-06-27_031011_me.jpg Gary's Avatar

    Gary

    Chevy Technician

    Satisfied Customers:

    5404
    15 years GM master tech
  • http://ww2.justanswer.com/uploads/testedtuff/2009-09-26_170108_pictures.jpg John's Avatar

    John

    Master A.S.E Automotive technician

    Satisfied Customers:

    4071
    A.S.E MasterTechnician A1-A8 w/L1,38 years experience General Motors Master Technician
  • http://ww2.justanswer.com/uploads/RO/rodcuda/2011-7-25_224114_Donhoff1.64x64.JPG Neal's Avatar

    Neal

    Chevy Mechanic

    Satisfied Customers:

    2306
    Shop Owner and Mechanic on multiple makes.
  • http://ww2.justanswer.com/uploads/goodwrench9124/2008-11-09_220838_dscf0007.jpg goodwrench9124's Avatar

    goodwrench9124

    ASE Certified Technician

    Satisfied Customers:

    2041
    Ase Master Certified, GM Master Certified Tech. Awarded GM Top performer, Hybrid certified
  • http://ww2.justanswer.com/uploads/DR/drivefast1971/2012-1-12_172422_0009051tQKh.64x64.jpg Ron Z.'s Avatar

    Ron Z.

    - Chevy Tech -

    Satisfied Customers:

    1912
    18+yrs experience. State Inspector and Chevy Diagnostics