Electronic Transfer Case

Smither · June 21, 2004

I have the Auto4x4 on my '04 2500. I was on the interstate last nite and looked over and the "neutral" light was on the transfer case selector. I pulled over and it switched correctly into 2hi. I drove to a parking lot and put it in 4hi. It switched over fine. I put it back in 2hi and it switched over fine. No problems since then. I had noticed what I thought was excessive tire whine for the past few days, but it must have been the transfer case. Once I switched it back to 2hi, the noise was gone. My questions are, how would it have gotten into neutral? Maybe the kids pushed buttons in there and since the transmission wasn't in neutral, it didn't make the shift completely? Maybe that is why I was able to drive the truck with the transfer case in neutral? Second question, wouldn't I be hearing strange noises now if something broke or was damaged?

2k32500HDUSMC · July 2, 2004

My wife's 03 suburban did the same thing...started it and noticed the neutral light was on, I took it out of neutral and back into 2H, it worked fine, then it did it again this past week...took it to the dealer this morning. He had never seen this before. I'm going to drop it off next week for them to look at it. I'll post the results

Smither · July 2, 2004

Thanks HDUSMC, I'll be interested to see what they have to say. I've had no problems at all since then.

seadoons · July 2, 2004

That is really weird - I have a 2002 Silverado Z71 with the Autotrac transfer case. It has 4 buttions:

Automatic

2H

4H

4L

In order to get the transfer case in neutral, the truck is not supposed to be running. You put the transmission in neutral, push and hold both the 2H and the 4L button at the same time for like 10 seconds...the transfer case shifts to neutral, you move the transmission lever to reverse, then drive, and then park. Now the transfer case is in neutral as is the truck. I didn't think you could drive with the transfer case in neutral, because basically the truck is.

Weird...

Smither · July 2, 2004

That was my thought too seadoons. I wonder if my kids did it "driving" and since the transmission wasn't in neutral, it didn't complete the shift. I don't know. It took a 600 mile round trip after that just fine, and has been fine around town. I'll be waiting to see what HDUSMC finds out.

Blue-2001-Z71 · July 4, 2004

Could this be that same problem that was causing my Service 4WD light to come on. I hear there was a big problem with the T-case switch in the dash going bad and either going blank, causing a bad indication, or throwing the light. Just a thought. The problem I had with my '01 auto 4WD system was the switch; $38 and it hasn't come back.

millerwd · July 12, 2004

I know for a fact there is a firmware revision that needs to be installed on the 04 K2500 HD.

The dealer installed it in mine after i got a "servcie 4WD" message at aprox 3800 miles.

Billm

Smither · July 21, 2004

Well, I finally took it to the dealer. I started getting what felt like wheel slip coming away from stop lights on dry pavement. Dealer looked at it and said it was the transfer case switch. So what Blue-2000-Z71 said was right on!! Hope this helps somebody.

UPDATE: It was NOT the switch, but the transfer case modulator. They replaced the switch and reprogrammed the modulator and it still did not fix it so they put in a new modulator and that fixed it. The dealer assured me no damage was done. Gonna get my new s.s. tailgate cables put on too, so i guess it was a good trip to the dealer.

Blue-2001-Z71 · July 22, 2004

Yeah that's the other common problem. They start with the switch. If it's not that, then it's either a computer reflash or the x-fer case module. Start cheap, end expensive, that's the name of the game!