4WD Hi does not work

[jvaughn]

Hello. I have a 1996 Chevy Suburban and the 4WD Hi does nit work. 2HI, and 4LO work perfect. This has the electronic transfer case (buttons on dash). What is the proper procedure for diagnosing this? All fuse are good.

The previous owner says it work fine until the fuel pump was replaced (supposedly). Since I've had it, the fuel pump went out again, so I replaced it (AC Delco this time), and was no where near the transfer case.

Any help is greatly appreciated!!

[vncj96]

a dealership can test it for around $65 or get under the dash and follow the wires for the module, a wire could be worn or cut

[Diggler]

I'm having the exact same problem with my 96 Silverado. I've got the buttons on the dash and they aren't lighting up properly anymore. I've pulled my front actuator and bench tested it, works fine. Althought I suspected it would since I have 4low.
I spoke to a dealership in the area and they said it might be a the switch/sensor on top of the transfer case. I pulled it out, it's a 3 wire plug on it with a ballcock plunger inside. It has no action when applying power to it, but not sure if it's supposed to do anything that way. I'd love an answer to this question, I've been driving myself nuts trying to figure it out for a while now.

[jvaughn]

I had a GM certified tech (cars only) say that GM had problems with the transfer case control unit in the early years of push button 4WD. I just don't know how to test it, other than using a known good unit.

[Diggler]

I tried a new switch for the top of the transfer case, and that didn't work. I have reason to believe that it's the motor on the side of the transfer case, but just didn't wanna throw money at it for no reason. Anybody have any insight?

[Diggler]

Anybody have any ideas?

[vncj96]

a dealership can test it for around $65 or get under the dash and follow the wires for the module, a wire could be worn or cut

X2, I am talking about the actual push button unit in the dash, start from there