Electronic transfer case problem

"NetWeasel" wrote

Probably not....but maybe you can try a few things. Start by seeing if there are any codes in the t/case module. Turn off the key, ground pin 13 at the scan tool connector under the dash (pin 13 should be 5th pin over from the left, bottom row), turn the ignition back on again, check the t/case dash switch lights...they will flash a sequence of lights. Most common code I've seen is 2. 1-4 is all that you will see.

If you get a code, write it down...or remember it. Now clear the memory of the t/case module. Turn off the ignition switch, remove the 10 amp CTSY LP fuse from the fuse panel...this should be on the side of dash when you open the drivers door up. You "must" wait at least 60 seconds before you re-install the fuse. Once you have re-installed the fuse, you then must cycle the ignition switch on and then back off 5 times. This clears the memory of the t/case module. See if you can get the correct shifting now.

If that doesn't work...you may need an encoder motor. I'd also be suspicious of the front axle too. It's also possible that for whatever reason, the t/case module is not seeing the front axle disconnecting, so it can't complete the shift into 2WD. When you shift into 4wd, the transfer case is shifted mechanically, and the front axle is engaged by a vacuum motor. The front axle has a switch that tells the t/case module that it is in fact engaged, which is what turns the

Ian

Thanks Ian!

This is what was wrong with the 2000 ZR2 that I had. They replaced that encoder motor two times for me, I believe. My wife was able to get the thing out of 4x4... We've found that if the truck is going over bumps, it helps it to disengage. She pulled up onto a curb and then pushed the button and drove off to bump the it around a bit. It seemed to work after the 3rd try. If this is the route I have to go, what is a fair price for this? Is this something that must be done by a dealer?

If this were the case, would the truck say 4hi but really be in 2hi? Or would it force it to shift back into 4hi? The blazer is definately still in

The blazer has another issue... My wife just informed me that it's been occasionally hard to start, and stumbling/stalling lately, and the dash lights will come on (air bag, abs, etc...). It's an automatic, so it's not like she's stalling it. I had the fuel module replaced last year in January. The year warranty on the replacement is almost up. It was replaced out of town, since we weren't home when the fuel pump failed. Does this sound like a fuel pump problem or some other electrical issue? The dash lights are confusing me. I want to be reasonably certain that this problem could be fuel pump related before I drive an hour back to the dealership who did the work last year.

Thanks!

-NW

"NetWeasel" wrote

If your wife was able to get it out of 4hi...you may want to check your tire pressures. Are they all even? Often, if tire pressures are not even on a 4x4....you can get driveline binding while in 4hi which makes it almost impossible to get out of 4hi. Generally, by going between reverse and drive...and/or disengaging while you are on a slippery surface while get you out of 4hi if the driveline is binding.

Encoder motors are "expensive". Up here in Canada, they are close to 1000 dollars retail. Best be sure that that is problem before you go either installing one, or having one installed.

The encoder motor will not complete the shift if the conditions aren't met. So it's either unable to complete the shift at the t/case, or it's not seeing the front axle disengaging and is unable to complete the shift.

Hard to say on this one.....this is not my area of expertise. A person would want to determine if the dash lights coming on is a separate problem, or is it just related to the stalling condition....ie: the engine is quitting causing all the lights to come on.

Ian

Never mind about the stalling... she just told me tonight that it was almost empty at the time, and that she had just started it, was moving very slowly, and turning the wheel hard. Thanks,

-NW