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Chevrolet Tahoe Suburban 4 Wheel Drive Indicator Lights



  • I looked under the truck yesterday, but didn't see anything that looked wrong (disconnected)
    Today I'll stop by the Chevy dealer (parts dept) to see if I can pick-up any additional info regarding fuses and their location. As I previously stated I only found 3 fuses relating to 4WD system (4WD, TREC, B/U LP) but am still trying to find out whether I actually have a fuse for the ATC or a 4 x 4 Module. For all I know the fuse labeled 4WD could be the ATC (Auto Transfer Case).

    If anyone has any other ideas, please advise.
    Thanks for all the comments and suggestions so far.
  • niktnikt Posts: 24
    Referring to my previous messages, you may recall that on my 1999 Tahoe, the ATC fuse blew twice. This fuse evidently protects the so-called "encoder motor" that shifts the transfer case from 2 Hi to 4Hi, etc. I concluded that the failure to shift was the fault of this shift motor. I checked the 4 WD option code from the option code plate located in the glove box door, then cross-checked it with a Chevy dealer parts person to determine the GM part number for that option code, then checked the applications listed on the Dorman (aftermarket parts mfr) website to find the Dorman replacement P/N. I then ordered the part from a local car parts store rather than mail order in case the part was faulty, wrong, etc., and could be returned. After all this, the store still ordered the wrong part and it had to be-ordered

    A skilled (ASE certified) mechanic installed it for me in about one hour's time and the 4WD system now seems to be functioning correctly. I notice that shifting occurs more quickly.

    Check and double check your transfer case option code.

    If you do get a part, make sure it's the right one.

    Don't substitute a bigger ATC fuse, you could have fire in the wire harness.

    My opinion: I avoid using the Automatic 4WD as I think it engages harshly.

    So far, so good. Best of luck to you all.


  • Good news!
    I purchased a Haynes Repair Manual and a friend of mine ( with wrenching experience) came over on Saturday and we diagnosed the 4WD system from the automatic pushbutton to the Acuator/encoder motor at the transfer case to the front axle shift motor (acuator).
    Turns out that it was a bad front axle shift motor which is probably the easiest item on the 4WD system to change out :) The unit screws right into the axle tube..

    Thanks again to all of you who made suggestions and shared their issues.

  • niktnikt Posts: 24
    To notawrenchguy,

    Good job! Please tell me the title or publication number of the Haynes manual you used.
    As my Tahoe ages, it may need more repairs, so a manual will be a big help.

    Good luck,

  • Nikt,

    The Haynes Manual ( # 24066) I bought covers Chevy Silverado, GMC Sieera 1999- 2006. it also covers Suburban, Tahoe, Yukon, Denali, Avalanche, etc
    You could probaly check it out on-line or at your local Napa Auto Shop (or similar)

    Take care.

    I guess I'm now "kind of a wrench guy"
  • I have a problem that consists of the "Service 4WD" message comes on and now the damn thing won't come out of 4LO. I was wondering if there is any way of disconnecting the solenoid/actuator and getting back into 2WD?
  • niktnikt Posts: 24
    To notawrenchguy:

    Disclaimer: Although I got my Tahoe 4WD working, I am NOT a 4WD drive guru.

    But, I do want to help. Based on my experience watching the mechanic install the shift (encoder) motor onto my transfer case, and my taking apart the faulty shift motor unit, here is my take on the shifting process and what I suggest:

    The shifter motor bolts onto the transfer case and the actual connection is a short shaft that comes from the transfer case that mates with shifter motor. The shifter motor is controlled by the Transmission Control Module (TCM). when you call for 2WD, 4WD, etc., the TCM tells the shifter motor to rotate that stub shaft to engage couplings, etc. that I imagine control splined shift collars, etc. The TCM does two things: It electrically releases a spring-applied brake and spins the shift motor that turns the stub shaft to the selected function (2WD HI or OR 4wd HI, etc.). A rotary position sensor tells the TCM when the correct function has been selected and the motor stops and the little spring-applied brake holds the shaft in the right place (Drive function).

    Now, the new shift motor comes with a plastic tab holding it in Neutral position. The owner's manual tells how to put the transfer case in Neutral so the new shifter motor can be installed, but the mechanic that fixed my Tahoe simply took a wrench and turned the stub shaft until he reached Neutral, and then installed the new shifter motor unit.

    I conclude from my experiences noted above, that you could remove the shifter motor, rotate the stub shaft to 2WD HI, and drive away. A BIG CAUTION here though; you must find away to lock the shaft in 2WD HI, because you don't have the little brake in the (now disconnected) shift motor unit to hold the shaft in position. Also, you will have to perform a short driving test to assure that have 2WD. If you are electrically and mechanically handy, or have a friend who is, you might be able to energize the brake and motor from an external 12 Volt source to do the shifting. Just don't energize the motor until you energize the brake to release it.

    In short, it is possible to get back to 2WD, but please be careful to lock the shaft.

    I hope all this helps.

    Best of luck to you and please let us all know how you make out on this fix.

  • I also have a 1999 Tahoe and have trouble getting into 4HI during the big East Coast Blizzard this weekend. It finally went in and now it will not go back to 2HI. When I hit the 2HI button, I can hear the motors underneath making noise and the relays in clicking behind the dash. The 2HI lights flash a few times and simply goes back to 4HI. It will not go into 4LO either. I tried warming the transfer case area and motors with a heat gun, no luck, Pulled the fuses as suggested above, no luck. Went back out after luch and now the lights on the selector are dead; fuses was blown. As soon as I intalled the new fuse it blew.

    Just dropped it off at the local Chevy Dealer and I am impatiently waiting for the call. Based on the symptoms read in this thread and what I have described on my Tahoe, does it sound like the motors were locked up and now they just seized, causing the over-current?
  • niktnikt Posts: 24
    To: mwdaniel

    Speaking not as an expert, it sounds like you diagnosed the problem correctly. I'm guessing the dealer may have to scan the TCC for trouble codes to see what else, if anything, may need repair. Your Tahoe is like my '99 Tahoe, and after 10-11 years, "stuff" just wears out.

    Good luck on resolving you 4WD problem.

  • Well the dealer told me that they need to replace the encoder module behind the dash, that was going to be approx $700, if that did not solve it, they would have to replace the encoder motor, add another $700. There is no way I could spend that just to have 4wheel drive a few times a year. I had them lock it into 2 hi, they pulled the motor and disconnected the drive shaft, so I now have a 2 wheel drive Tahoe. Set me back a couple hundred dollars.

    Thanks to all the thread posting out there.
  • My 2003 Tahoe indicator gages on the dashboard are begining to go out. My mechanic tells me that the resistors are failing, hence the gages going out and sometimes re-setting again. I have heard that this is a more common than not problem with Chevy and GM Trucks. The repair seems to be replacing the dashboard completely - a pretty expensive option.

    Any information on if this is happening generally or how it has been handled would be appreciated. Thanks,
  • kiawahkiawah Posts: 3,666
    Do a google search on replacing insturment cluster. There are companies who will repair your cluster, and it's relatively easy to do, video's available which show you how to take it out and put it back.

    There's another edmunds forum on sub/tahoe with many posts on this subject.

    It's not as expensive repair as you may think.
  • I have a 2000 Chevy Tahoe and my service 4WD light comes on every time I drive my truck about 15 miles. I can switch it in and out of 4 wheel drive with just 1 push of the button and it does not make any noises when in either 2 wheel or 4 wheel drive. I had the front differential fluid changed and the light still comes on. I don't want to take it to the dealer because over the phone they have already let me know they are going to take me for a ride. Took it to Auto Zone and their computer shows no codes. Disconnected the battery and light still comes on. Can anybody help me with this problem.
  • swifty20swifty20 Posts: 8
    On my 2003 suburban all the light for the 2wd, 4h, 4l, N lit up all at once and stayed on. I ended up taking it to the dealer and they had to reprogram the computer module for the 4x4. Have not had any problems with that since then. Has been over 3 plus years now.
  • I've only owned my 2004 since August and have only had the one problem with my front accuator.
    Sorry I can't help.
  • i have a 2000 that im suspecting the culprit to be this issue. everytime i switch from 2x2 to 4x4 i hear a big clunky noise coming from the rear axle. now that i come to find out this shift on fly 4x4 isnt the same as im used to . i hope i didnt do bad damage to my truck.
    Now it seems to be stuck in either 2x2 or 4x4, but the truck doesn't seem to accelerate properly. Might this be the issue? any help would be appreciated.
  • killa202killa202 Posts: 3
    We got our Tahoe about two yrs. back while living in Colorado, never took it off "AUTO" setting and maybe it engaged a dozen or so times on its own.
    Then one day the tramsmission went "CLUNK" and the light went from "AUTO" to 4 wheel "HIGH" without any request from the driver. I reset the "AUTO" position on the switch and there was noise and then no lights on the control panel. The lights stayed off for 6 months and in that time we relocated to south Texas.
    About three weeks ago the light for 4 wheel "HIGH came back own and I reset it for "AUTO" with no results, so, I tried 2 wheel and it came on properly. My wife drove the vehicle for about two weeks during which the lights switched from one to another and back again...during that two weeks, we had it at the dealer TWICE and they sent us away with an appointment to return at a later date...no problem..right?? WRONG ANSWER!!!!!!
    On Friday 5/28 the Transfer Case errupted and the case was cracked beyond repair. The symtoms never raised a red flag with the service department who said it only need a $250 part and reprogram of the control computer.
    Believe it or not it still drove normally after the explosion, albeit, with some tinking sounds at low speed. The vehicle is hospitalized at present and we do not have a prognosis and are not sure if our extended warranty will cover this repair.
    The rental suv is nice and we are holding our breath...I will post additionally when the damage estimate comes in..
    LESSONS LEARNED>>>>so far.
    1. Never ignore the absense of an indicator light..have it checked.
    2. The service department may NOT always steer you correctly.
    3. The information here is more reliable than my dealerships service dept.
  • gmcustsvcgmcustsvc Posts: 4,252
    Hello Killa202,
    I am from GM Customer Service. Please keep me posted on how everything goes at the dealership. Thank you,
    Mariah GM Customer Service
  • killa202killa202 Posts: 3
    Mariah GM Customer Service:
    Hello and Thank You for your interest in my issue.
    The Tahoe came thru the service event with a Rebuilt Transfer Case that was installed due failure of the in-service part @ the upper gear which ruptured the rear housing cover, there was also a shaft that was replaced as part of this portion of the repair. My wife was @ 65 to 70 mph when the transfer case attempted to engage and this damage occured. The cost for this repair was $2700 (approx.)..It appeared that the failure was the result of the attempted engagement of the 4x4 drive unit as a result of the malfunctioning selector switch, not sure that it was not caused by the electrical sequencing module that I have read about in post.
    Financially, this was an absolute nightmare...our 100,000 warranty was found to be a 3 yr./36,000 mile warranty and expired @ 78,400 miles...OOOPPS.
    The other repairs, tachometer failure, climate control computer and the ever present clunky steering column added an additional $700 to the invoice. The climate control problem is still present as is the steering column clunk, although somewhat better. Altogether, $3647 and change, out of pocket.
    My background is in aircraft maintenance for over 35 yrs. and I know that mechanical things wear out and need service periodically, had I been advised that this kind of failure was possible/probable based on the symtoms that the service department had reported on the previous visits in the weeks leading up to this event I could and would have taken steps to leave the vehicle for repairs prior to this event.
    The family loves the Tahoe, previously we had three Suburbans, a C3500 4 door truck and a C1500 regular cab truck. I restored a 1961 Apache 10 truck and have had several ragged out Chevy trucks over the years.
    I wish I had seen this coming.

    Lessons Learned:
    (1) Loving your vehicle does not make it bulletproof, always get the maintenance done when the problem is first encountered....mechanical problems are not self-healing.
    (2) Many maintenance issues do not exit in a vacuum, get all the current information that is available thru internet channels, the information is up to date and in my opinion more reliable than some service providers will give.
    (3) EXTENDED WARRANTY...Check yours for relevance, coverages and deductibles. I blew this one "BIG TIME".

    Glenn Hayes
    La Vernia, Texas
  • gmcustsvcgmcustsvc Posts: 4,252
    Hello Glenn,
    Did you tell the dealership that the steering clunk is present and the climate control problem is still there? I am glad the rest of the concerns have been taken care of. Thank you for letting me know how everything went. If you have any other questions please let me know. Thank you,
    Mariah GM Customer Service
  • agichkagichk Posts: 1
    Recently I had my power steering leak fixed and shortly after, I would start up my 2003 Z71 tahoe to find the transfer case model in neutral. Over the course of the that week, it started to happen more often. I took the vehicle back to the dealer on the 14th of this month.

    The dealer couldn't get any codes but had a tech drive my truck home & after sitting all night, it acted up on the tech driving back to dealer. The dealer replaced the transfer case module to the tune of over $500. Repeated the same thing w/o problem replicating. I took my truck thinking all is well. HA HA.

    5 days later, I found truck in Auto 4WD & put into 2H using buttons immediately, thinking I might have hit it by accident. That night, turned on truck & in neutral. So $500 fix didn't work. I found that restarting truck would re set to 2H.

    12 hours later, my truck turns on in 4L. Restarting does nothing on 4 tries. Drove it as no choice to get to appt at 25mph on interstate. Of course on way to dealer, it is in 2H. Dealer finds no codes ( of course). Tech drives home & acts up next morning. Switch is replaced. Problem is still replicated by tech 24 hours later. Dealer does work on wires next. Problem is replicated by tech 24 hours later.

    GM was apparently called & sensor was replaced with no replication on friday but dealer wanted to make sure. Tech drove it home w/o replication last night.

    I was told that I could get my truck at 7am today and knowing I had to be at work at 8am, I was there at 7:15am. I had called dealer last night from work to notify them I would be in very early & needed my truck ready to jet after I paid for the parts. Imagine my luck when service rep told cashier and courtesy guy that "I can wait" as guy needed to pull cars into service bay. I couldn't wait to get my truck, so I went to look for it & didn't succeed. Neither did 2 other people for 20 minutes.

    So I am late to work, out $500 for the module, 2 days of rental car last week, switch and sensor cost too. I am thinking of visiting service mgr for the unnecessary replacement module since everything done but 1 didn't fix problem.
    Other family members have 3 suburbans from 1999 to 2008 and 1 tahoe 2009 -all have 4x4 & never had this problem.
  • neddanedda Posts: 2
    I was driving on snowpacked roads and needed to drive up a steep hill. I tried to transfer from 2wd into 4wd (hi) but the switch over didn't happen. :sick: My 2001 Tahoe stayed in 2wd and the message center signaled a Service 4WD message. I drove home in 2wd. The buttons on the panel that allows you to switch from 2wd to 4wd (hi) or even 4wd (lo) didn't work from the moment I received the message for Service 4WD. I switched the fuse for the 4wd (15 amp) and nothing happened. I then opened the hood and replaced the ATC (20 am) fuse and the problems was fixed. Just wanted to leave a note that might help someone else who may run into the same problem. Test drive was successful. :shades:
  • I can save you a lot of time tinkering with 4wd problems. I did it for years on 2003 chevy tahoe 5.3 Z engine. Replaced front actuator (dont use the gas piston get the non-gas model), 4x4 switch on dash and transmission motor switch. The transmission motor switch was the item that was last and resolved all my problems. I had service 4x4 being displayed, 1.5 minutes to switch from 2wd to 4wd, 1.5 hours to switch from 4x4 to 2wd. Warranty never would fix it because I could not replicate the problems in front of them. Imagine car posts serverice 4x4 but technician has no idea what to do (5 dealerships visited) No MIL codes or transmission codes eventhough the service 4x4 light would come on. GM home office service calls were useless.
  • Mechanic12
    I am having the same "service 4 wd" light on the display. 2004 Tahoe Z71. did you replace the transmission motor switch yourself or did GM do it? If yourself, is it simple enough to do? Where did you get the part. can you please give me some pointers on replacement. :)
  • I changed the actuator switch on the front differential and had a 4 wheel drive mechanic change the transmission motor switch. I bought the actuator from "http://www.dormanproducts.com/applicationguideresults.aspx?y=2003&mk=CHEVROLET+- TRUCK&md=TAHOE&e=V8+-+5.3L+(323+CID)%3a+FLEX%3a+FI%3a+N%3a+Z&c=4&cn=4WD+AXLE+ACT- UATOR" and my mechanic bought the switch. The advantage of dorman actuator is that it is not the gas controlled piston which is cold temperature sensitive. There are tricks to install the transmission switch so I would not recommend doing it by yourself since you can seriously kill your transmission. Good luck! It is well worth the money for the two components.
  • The 4wd / 2wd dash lights on my 98 Tahoe are not working properly. I pulled the fuse and reset the code and this worked for a few starts before they failed again. If I press on the 2wd button when I first start, it will nornally engage, but it won't stay set (it may fail while driving, or on the next start). When the lights do work, I can hear the shift into 4wlo. Any suggestions on where to start would be greatly appreciated.
  • Just for the record... the Transfer Case Fuse on a 1998 Tahoe with the push button 4-wheel drive is in a little door on the side of the dash (open the drivers door and look at the dash). The fuse is marked "T Case".

    My story, just in case your interested:

    Had the oxygen sensors replaced and, two days later going down the freeway... rip, thud, thud, thud, rip, bam! and rolled to a stop. The sensor wiring harness was wound around the front drive shaft. Along with the sensor harness was the transmission wiring harness as well as the transmission linkage. Also ripped out the linkage bracket.

    After a week in the shop 300 miles from home, the harnesses, linkage and bracket were replaced with a mixture of new and scrapyard parts. No... I didn't pay $2300 for a new transmission harness... lol.

    When I picked it up after turning in the rental, I found that the 4 wheel drive did not work. Lights on the indicators worked somewhat and, when anything was pushed, "neutral" illuminated... but no response down below. Drove home in 2 wheel thinking I'd work on it more later. Yes, I could have held the shop responsible for missing it but, frankly, I'd had enough for the time being. Remember... 300 miles from home.

    Kudos to this forum. May I say again... KUDOS TO THIS FORUM AND ALL WHO POST! Finally found the 20 amp T Case fuse, replaced it (it was blown, of course) and as nikt said, even though the keys were nowhere near the ignition, I heard the click of the transfer case. Started it up and all is well! :)
  • Please look at this post: 4x4 disengage and engagement issues resolution [kingdvb] by mechanic12 Dec 06, 2010 (11:44 am) I would be very concerned driving your car. It has been reported the transmission automatically shifting from 2wd to 4wd on its own. If this happens at over 45 mph this could cause tremendous problems. My undeducated guess is the transmission case motor switch is not sure what mode it is in (4x4low, 4x4high or 2wd). I would replace the front actuator and the transmission motor switch. Since I have done this I have not had a single problem with my 4 wheel drive. I hunt almost every weekend so I use my 4 wheel drive frequently.
  • cchulescchules Posts: 2
    edited December 2010
    i have a 94 chevy suburban with a 454 big block and i can tell that the 4wd is engaging at transfer case but the front axels are not locking in
    thanks for any help
  • i have a 95 4dr 4x4 tahoe 5.7l i have a 300 hp rated transmission with a level shift kit from monster transmissions. i have checked actuator and t case. i have the floor shifter. tcase engages u can hear it click. i bought a new actuator but it didnt make a difference. so i made sure the old one worked n took the new one back n got my 80 bucks back. i have got my dad to drive it while i held the front driveshaft to see it it was turning in 4 wheel it was so im thinking its in the hub or it might be the thing in front of the actuator. any suggestions please. i have replaced every brake line and hose caliper to wheel cylinder, master cylinder. radiator blew out when i hooked the tranny up blew the sides out of it lmao this truck will be all new b4 long.
  • I have a 2004 Suburban when I push the button for 4H, 4L, or auto 4 wheel drive,
    the lights on the dash seem to work properly, they flash for a moment then stay lit, but the vehicle never engages into 4 wheel drive, any answers ?
  • mikeanddreamikeanddrea Posts: 2
    edited April 2011
    Here is a list of numbers and documents that may help you out. Just do a Google search. If you want to know more about my experience with our 2005 Suburban that had a mere 60K on it when I had to replace the entire transfer case, my email address is ebpsi2000yahoo.com

    Reader's Digest version: Heard a rattle up front, and could not figure out what it was. This happened for about a month, and then my transfer case started to neutralize on it's own. Took it to a local transmission shop here in Tucson, and they could not figure out what was wrong. Everything was MECHANICALLY perfect with the transfer case. Took it to O'Rielly Chevrolet here in Tucson, they tore my transfer case apart, and told me that I had the WRONG PARTS in my transfer case. Excuse me? How the hell could I have the wrong parts in my transfer case? I even have this DOCUMENTED!!! Needless to say, I ended up paying $2500+ for a brand new transfer case.

    Fast forward a couple of weeks later, and I came across the documents below. Turns out the rattle that I heard was from the transfer case main shaft and the inner clutch hub assembly. The early designs of our transfer case came with a "slip fit" design for these two parts. The parts were rattling, CAUSING ENCODER MOTOR FAILURE! The encoder motor failed, causing my transfer case to neutralize itself when simply driving down the road in 2wd.

    The following documents go on to explain how the Chevrolet techs are to replace the two parts with "the inner clutch hub and shaft, which will have a PRESS FIT design and eliminate the rattle condition."

    Common sense tells me that the tech that tore apart my transfer case at O'Rielly's looked at my ORIGINAL SLIP FIT clutch hub and shaft, compared it to pictures/documents of the newer PRESS FIT clutch hub and shaft, and deduced that I had the wrong parts in my transfer case, and thus that must be the problem. All along, turns out that it was because of a DESIGN FLAW in the original transfer case that caused the encoder motor to fail, causing neutralization of the transfer case, costing me over $2500.

    I got nowhere with the dealership, nowhere with GM Customer Care (yes, I do have my GM Incident Number - let's see if anyone from GM Customer Care "cares"), and I promise to God that this will be the last GM product I EVER BUY.


    Also search on Google for: "DTC C0327 #PIP3480K"

    NHTSA Item Number : 10017299
    NHTSA Item Number: 10018926
    NHTSA Item Number: 10018607
    Service Bulletin Number : 3665
    Service Bulletin Number: 3480A
    Document ID: 1884845
  • I have a 98 tahoe and the 4wd service light came on. when i was on my way home and it shifted itself into neutral. i did the ignition thing and disconnected the battery. All the fuses are good. after i disconnected the battery it shifted into 4lo and is now stuck in 4lo. i dont want to spend money throwing a bunch of new parts at it. any help will be appricated
  • Sadly gm does not have a way to quickly diagnose the problem has been my experience. Read my previous summary post. I would replace the transmission switch on the transmission and the motor on the front that engages the front axle for 4 wheel drive. A lot of time and pain can be spent trying to diagnose this problem. There is a previous post that explains how the engaging mechanism works. This is a small $ to pay to insure you don't destroy the transmission.
  • I have a 99 Tahoe LT, sometimes the four wheel drive indicator lights are on and sometimes they are not. If they are on and I try to engage the four wheel drive the lights just shut off. Any suggestions?
  • keep blowing fuses for the transfer case fuse #2 in block of fuses on drivers side of dash. replaced fuse and was fine for awhile as long as I was in 2wd but when trying to switch to 4wd it would blow. replaced the switch cluster in the dash for the push button 4wd and went to try engaging 4wd and it blew again and now everytime I go to put a new fuse in it blows instantly. I unplugged the front actuator and tried replacing the fuse and it still blew instantly so I dont think its the actuator. Not sure what to try next? Im thinking Transfer Case Vacuum Switch? Any other thoughts?

  • does everything else still work fine? it still switched into 4wd and everything? if everything else works fine it could just be the cluster for the push button 4wd. just replaced mine for a 98 tahoe was $55 for the switches and then very simple to swap out. whole assembly just pops out with a flat head screw driver and then 2 plugs on the back to unplug and plug into new assembly and pop back into dash.
  • When replacing your switches did yours have the 4 button system or three? If you have the 4 button system (4wd auto being the 4th) where did you find the switches for $55? Thanks Troy
  • Buddy who works at a GM dealership got it for me for that price with his discount. think it was around $70 without discount. This is for the 4 button system with 4wd auto. part #19168765 if you need it. Kinda got lucky with them having 1 in stock.
  • replaced the front acuator also now and still blowing fuses whenever I try to swith into 4 hi or lo as soon as I touch the button? Possibly a short in the wiring? any other thoughts?
  • mrlesmrles Posts: 1
    Hey Boelter21,

    Being an electrician for 40 years, I would definately say you have a direct short some where. Try and disconnect each part one at a time and meter to ground to find the problem. The side sliding door on my mini van quit working, and luckily I noticed the sparks coming from the traveling wire harness at the bottom of the door.....the insulation they used just deteriated.
  • I wanted a suburban since i got my license at 16 and drove my aunt and uncles 88. So I'm trippen here, LOL. When I turn on the 02 that I now have, all 3 (2WD, 4Hi and 4lo) lights come on for a second. That's fine it always did that. Now they come on and do their thing but the Service 4WD light is coming on for a few seconds as well. The lights also make a loud ticking sound when they go on and off that they didn’t before. THAT my friends, did not happen until today. Damn cruise control makes a tick sound when its set as well. I’ve seen similar things I think in other stuff that’s just aged in wiring but i don't know. I havent done anything with the 4WD (like screwin with it on dry pavement and the such) so I don't think it's anything with the hardware cause I'm sure if it was the light would stay on, screaming for help, haha. Still though why is the damn thing coming on though. I'm afraid it'll stay on starting tommorow or the next day or next week etc. My father didn't take very good care of it and then signs the damn thing over to me. I'm trying to refurbish this baby inside and out. Last sh*t I need is 4WD goin to sh*t, :'-(. One gentleman said something about the wiring harness and that could be $600. I like that better then 4Gs for a whole new unit. Any advice or possibilities I can do now to prevent further more serious problems is greatly appreciated.

  • To mrles: When I turn on the 02 that I now have, all 3 (2WD, 4Hi and 4lo) lights come on for a second. That's fine it always did that. Now they come on and do their thing but the Service 4WD light is coming on for a few seconds as well. The lights also make a loud ticking sound when they go on and off that they didn’t before. THAT my friends, did not happen until today. Damn cruise control makes a tick sound when its set as well. I’ve seen similar things I think in other stuff that’s just aged in wiring but i don't know.
  • ended up being the encoder on the transfer shaft was bad
  • Is that 2 grand to fix? :-/
  • my 03 suburban had this problem a year ago and I too removed the TEAC fuse and put back and it was fine until today. So I did the same thing again and now its stuck in 4wdlow. Anybody got anything for me?
  • no it was around $700-$800 to fix the encoder on the transfer case
  • bird29bird29 Posts: 1
    I replaced the Transfer Case switch 3 months ago and the light has not returned. There is a problem with the soldering in many of the original switches, which causes the trouble. Bought a Dorman switch online for $30, took 5 minutes to install. Good luck!
  • My '04 Tahoe is doing this EXACT same thing! I noticed one night on my way home that my 4x4 indicator showed I was in Neutral, which doesn't make one bit of sense since I was MOVING. I came home and told my boyfriend about it and we just figured it was an electrical issue. I started it up the next day and it showed in 2H so we just wrote it off. Then, it happened again while he was in the truck with me but, once again, we were still moving. He and my dad (both are ASE certified mechanics, mind you) replaced the axle seal on the rear differential and also checked the transfer case fluid level. My boyfriend found the fluid level was high but clean so drained some off. My readout has said "service 4x4" for a couple weeks now and we thought this would take care of that issue. Well, I kept getting that readout and now, today, on our way out from our home the truck felt strange to me, like it was trying too hard to move. I looked and found the indicator showed in was in 4L!! We quickly pulled into a parking lot (we hadn't gone more than a half mile) and I put it in Neutral and pushed the 2H button. It did switch out of 4L but there was a loud clunk when it did so. We brought it back home and that's where it will sit until I can get some answers as to what in the world is going on! What did you find with your issue? Did anything finally work? I don't want to have to go thru a trial and error, spending unnessary money that we really don't have, to not have the issue fixed. Any insight is greatly appreciated.
  • There are a lot of rumors that are mentioned. In my experience replace the 4x4 switch on the dash, replace the front actuator (on front axle) and replace the transmission switch (on transmision). Should be able to do this for parts under $700. It is a very intricate system that has checks and balances between the 3 parts. Not to mention parts that are known to fail. Unless you want to troubleshoot a lot I would put the new parts in like I did. I have not had a problem since. The original front actuators used gas which was not accurate in cold temperature and did not perform to specs very long. The actual transmission switch controls the 4H/4L and the dash switch tells the transmission switch what to go to. It could be the wiring between any of the 3 but I have not personnally seen this. 99% of the time it is best to replace all three because if you are on the interstate and the system does go into 4L or 4H then you will have bigger worries like the transmission and motor.

    Good luck!!!
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