Chevrolet Tahoe Suburban 4 Wheel Drive Indicator Lights
I have a 2003 Tahoe, and my indicator light changes from 2 wheel drive to auto or to neutral without me pressing any buttons!? Anyone else have this problem? I hope it's not expensive to fix :-)
Fixed My Blinking Push Button 4WD Problem
Fixed My Blinking Push Button 4WD Problem
I would tell you to have the truck taken to a dealer never you :sick:
I was told that the module does not sense the power so it does not turn on. now it been working fine for 3 months now and it did not cost me anything. This not a fix all solution but it worked for me. right now
There is a TSB issued, 02-04-21-006E. Available via subscription on All Data among other places. The TSB discusses removing the fuse as described in this forum. Failing that, the TCCM requires replacement. There is a reprogramming routine that must be performed on the new TCCM, have not done this myself but expect it is not all that difficult.
Also, I want to check the ATC fuse per the above messages, but my owner's manual doesn't show where it is.
Can any one please advise? Thanks,
I recently purchased a 1998 Tahoe with the right side of dash push button 4x4 with the auto 4x4 and the previous owner stated he was driving it in 4Hi and when he went to go into 2Hi it wouldn't shift and went into neutral.
When I bought it the Transfer Case Shift Motor was removed I was able to shift it manually into 4Hi, 4Lo and neutral but couldn't seem to find 2Hi. I replaced the Shift Motor and checked the fuses and it still wouldn't shift. I did get the lights on the dash to blink for a while and then they seemed to go out completely.
I took it to Chevy who put the motor back in (cuz I had to remove it to manually shift into 2wd) and stated it wasn't working because the Transfer Case Module under the dash was bad. $350 later plus labor they stated it tried to shift a few times and then burned out the Transfer Case Shift Motor $225 plus labor. After all this and not seeming to get it into 2wd they want me to replace the whole T-Case $750 used.
Any advise before I replace the T-case or does this sound wrong to anybody else?
I would appreciate hearing from anyone who knows where the ATC fuse is located on a 1999 Tahoe. Thanks for your help so far.
I realize your Tahoe is a 2001 and mine is a 1999, but where did you find the ATC fuse? I looked at my manual and opened the fusebox on the left front fenderwell, but didn't see the ATC fuse. The fusebox I opened has many fuses and relays in it. Is this the correct panel or is there another fusebox you're talking about, or does the ATC fuse have a different name or designation??
1.- Find ATC fuse. This took longer than everything else because I kept looking for an “ATC” fuse. At least on my ’99 Tahoe, there’s no fuse so marked. My manual did list a fuse in the small fuse panel on the left side of the instrument panel, but not in the panel over the left front wheel. It’s a 20Amp fuse in the No. 2 position, and is identified as “Transfer Case.” It was blown.
2. – I pulled the T-case fuse (#2) and the Accessory Light fuse (#3) and left the car sit for about 5 minutes with the ignition switch off.
3 – I replaced the 20 Amp fuse with a 25 Amp fuse, because some people suggested that cold weather can result in a higher current draw in the 2WD-4WD shift motor. I put back the 10 Amp Accessory Light fuse which was OK.
4. – As some suggested, I then switched the ignition On and Off 5 times to clear any trouble codes stored in the Trans Control Module.
5. – I fired up the engine and watched as the red “Neutral” light on the control button panel blinked off. My Tahoe had been stuck in 2HI, but then the 4HI button lit showing that mode was now engaged. I pushed the 2HI button and the transfer case shifted OK. Out on the street I engaged all the Transfer Case modes and everything seemed to work OK.
Again, a big thanks to you all, and I hope what I did works for you too.
You can also keep another spare if it does blow later. If it does, you'll know exactly what are where to replace it.
Thanks for your thoughts. You make good sense and I will change the fuse back to a 20 Amp unit this morning and keep some spares handy, Also, I will operate the 4WD drive selection every other day or so to keep the shafts or other components moving freely.
Also, is there another recommended lube oil for the transfer case? Some forums talk about a "blue" fluid for better lubricity, or is that to improve the Auto 4WD?
You know, I have never used the Automatic 4WD feature. I bought my Tahoe used (50,000 miles) about 9 years ago. I tried using the Auto 4WD in the snow, but I didn't like what I thought was a harsh engagement and avoided ever using it. When accelerating on snow or wet pavement, I engage 4HI to get up to speed and then engage 2HI. In winter here in suburban Chicago, when we get blowing and drifting snow, I engage 4HI and it seems to get me through just fine. I then shift back to 2HI when I'm back on dry ground. I'm coming up on 140,000 miles and I like my Tahoe just fine. The only repairs of consequence (how do you spell Co$t?) have been replacement of one fuel injector and about 2 years later, the in-tank fuel pump.
I'm having some 4 x4 problems.
The push buttons will engage 4 HI, but when it kicks in, the front wheels feel like they will pull to one side then the other and has an audible mechanical growl.
I've never had a problem with the 4 wd system on this truck. I don't know where to start with diagnosis.
The lights on the 4wd buttons all function, and the 4x4 system engages when each range is pushed , and dis-engages when 2 hi is pushed. It just pulls and growls when engaged.
The symptom seems to be worse when using the auto 4 wd feature.
Where should I start?
I've had this rig since new.
I can't speak with the authority of a mechanic, but only from my perspective as a Tahoe owner. You may already know this, but don't engage 4WD on dry ground.
If I correctly understand the way the 4WD system functions, engaging the front axle also causes the front axle to become a locked axle. That's necessary to prevent all the drive torque going to one wheel on very slippery ground, leaving you with very little or no traction. This means (to me) that one should avoid sharp turns of the front wheels while in 4WD unless you are on very slippery (snowy, icy) ground. I recall once forgetting to disengage 4WD and I could feel a terrific binding when I made sharp turns on dry ground.
Did you read my previous entry? I bought my Tahoe used, and didn't like the way Auto 4WD engaged and never used again. Maybe a Tahoe technician could advise on lube oil specs for the transfer case. I hope this helps.
If you believe the push button 4WD selector, all is fine. It switches in and out of 2 or 4WD no problem. However, based on recent driving I don't think it's actually engaged. If I actually get some decent slippage (ie, icy accelerating), it will grind from the front end like crazy. Sounds similar to grinding gears on a manual transmission (it's an auto, for reference). Only happens on slippage in 4WD.
Took it into the dealer, they've replaced a seal which they say went bad and let oil into my vacuum lines which then took out a servo and actuator. Still grinds, so they're thinking it's actually taken chunks off the gear and sleeve for the 4WD. $800 so far into it, gonna be about $800 more for the gear and sleeve. Does this sound right for symptoms/diagnosis? I'm not much of a mechanic and REALLY get lost on tranny/transfer case type stuff.
i found a use one at the junk yard for $300. my friend and I are going to put it in and see what we get. They are supposed to be heavy so a little bit tricky to do in the driveway. I'll let you know how it turns out.
Am I on the right track here? If not, any other suggestions?
Has anyone out there made this repair? Is Dorman a reliable product?
Looks like I have a similar problem with my wife's 1997 Tahoe as you are having. She shifted to 4WD the other day and now the thing is stuck in 4wd. Thanks to you I went right to the proper fuse and checked it - it was good. But I have a couple of questions about your entry #25, if you'd be so kind as to answer them. First; Why did you remove the Accessory Light fuse (#3) as well? Was that part of the reset procedure? Second has to do with switching the ignition On and Off 5 times to clear the codes. Can you tell me where you got that information. I'm asking becasue I couldn't find it on the web, but I may not have structured the search properly? Anyway either it's truly stuck in 4wd or I did something wrong because Nothing I did helped. :surprise:
I pulled the the ATC and Accessory Light fuses because it was suggested by a Chev/GM mechanic in another forum. To understand what these fuses protected, and before doing any of the things I described, I tried to find schematics for the transmission control system at our local library without success, so I can't tell you what effect pulling the fuse had. That same mechanic suggested turning the ignition on and off 5 times.
I thought I saved the the web address of that forum, but I couldn't find it in the my "Favorites" list. If I find it, I will let you know. I do recall it was an"Ask the Expert" style forum, and answers were free if were willing to wait a day or two for an answer. However, by paying a small premium you could get a quick return with an answer.
Do you have any thoughts about, or know of anyone who used a Dorman shifter motor?
Thanks for your reply. I forgot to pull the #3 fuse - I'll try it again with that out. I'm just getting into this stuff with this vehicle and am looking at replacing the TC motor as well. I really don't know anything about the Dorman Motor - just that it appears more expensive than the Cardone that I'm looking at.
I feel like I've entered Automotive repair hell. I've got 2 vehicles that won't pass inspection, The Tahoe and my wife's 2001 Sienna. We made an attempt with the Tahoe and found out that not only was it not simple (cheap) to fix the 4WD problem but the MIL indicator was burnt out and it also needs a Cat converter and possibly something else. The Sienna is an even bigger nigthmare in that it too has Cat ConV problems and a bad KnockSensor. The Knock Sensor is about $180 and is located underneath the intake manifold so it'll be at least that much to replace it. The Fun part is that the Cat Conv for the Sienna looks like an Unobtainable part until at least Feb 2010 and cost somewhere between 350 and 1400 dollars depending on where I shop. It's also tucked away in such a manner to prohibit anyone with a blow torch from working their magic. The only saving element is that my State has a kickout clause on inspections that allows a Waiver if you spend > $150 on a vehicle trying to fix it. So that's a temporary solution. This has all happened over the last couple of days, I feel a little shell shocked and am just trying to orient my self with what is going on and who/what to try and fix first.. LOL :sick:
surfing the net to find other Chevy and Tahoe forums.
I hope there is a guy with experience in these matters to advise us on repair and/or needed reprogramming procedures. I am digging into this as best I can because our local Chevy dealer wants $800 to $900 to replace the shift motor which is out of the question for guy not working a steady job (me). I just want to be sure I'm doing all the right things before I buy a shifter motor and try to install it.
So once again, if any of you folks out there have replaced the shifter motor (sometimes called the encoder motor ( its GM part number is 12386247) please tell us all about and any problems you encountered.
I'm sure a lot of you already know this stuff, but I confess to being a beginner. Years ago, when I scrounged for boneyard parts, RPOs and such weren't a factor--you just found what fit the car you were fixing. Of course my new questions are: Has anyone had experience installing this shifter motor? Any trick stuff to know about? Does any reprogramming have to be done? Is there a cheaper source for this motor?
Many thanks to you all and Merry Christmas,
Does anyone know of a good manual, say a Chilton or Haynes that focuses on GM 4WDs and transfer cases? I looked in our public library, but came up short. I'm not comfortable changing fuses, etc., when I don't even have a clear understanding of how the transfer case operates and how the shifter motor interfaces with what I am sure are splined shifting collars.
I suspect many of you are a lot more knowledgeable on how a transfer case functions than I am, and if you can help, please pitch in because I'm sure we could all learn something.
Thanks and Merry Christmas,
Thanks for your courteous and prompt response. I will follow up on your suggestion.
Anyone know whats going on?
Take a look at previous messages. Check the transfer case fuses.
If the fuse(s) are blown, there is a chance that the shifter motor is shot, and you may need a 4WD/2WD shifter motor, also known as an encoder motor. To correctly identify which one your Siverado uses, be sure to check your serial number/option data plate. Check your owner's manual for its location. Copy down the N-codes to determine which transfer case you have and the shifter motor you might need.
With the correct n-code, a cooperative GM parts counterman should be able to give you the correct encoder motor P/N.
Hope this helps.
These include fuse panels in the cab and under the hood.
Any thoughts or direction??
I looked at my owners manual
I'll check the fuses first and pray, although I've reveiewed some previous messages and just sent out another "question" because I can't find a fuse labeled (ATC) Automatic Transfer Case.
Just so you all know, my experiences with 4WD have been limited to my 1999 Tahoe and its particular transmission, 4WD control configuration, and fusing.
I can't speak with any authority on any other year or model GM product (heck, I can't speak with any authority on my own Tahoe).
My suggestion would be to check all fuses that seem to relate to the 4WD controls and replace any blown fuses. Then try the system. My Tahoe did have a blown fuse which I replaced, and I did restore 4WD operation. After a week, the fuse again blew. I have ordered a new shift motor from Rock Auto to make a hopefully permanent repair.
I caution you all to check your option data plate to confirm the transmission option codes to get the correct parts. In my area, a helpful Chevy dealer parts guy gave me the GM p/n for the shift motor for that code.
I can only say that fuses blow because of excess current and that usually means the encoder (shift) motor is possibly faulty and must be replaced
Today I'll look around under the truck for loose conections, etc.