Odd 4wd problem

[4BoltMain]

2001 Jimmy 4x4 (4 button dash switch).

Bear with me here folks and please read completely before attempting a diagnosis.

When in 2hi:
Pressing 4Auto results in several flashes and then steady on indicator.
Pressing 4hi does nothing. (No blinking light). 4lo engages without problem.

When in 4Auto pressing 2hi results in the 4lo indicator flashing and 4lo will engage if stopped or moving slowly. This is where it gets a little confusing. Pressing the 2hi and 4lo buttons at the same time while 4lo is blinking returns the transaxle to 2hi.

The vacuum actuator under the battery works just fine and I can hear the TCCM and encoder motor making the usual noises.

Thinking the dash switch may have crapped out but any input would be helpful.

Thanks

 

[jason wood]

4 wheel drive stuck in lo, couldn't post other than responding

Anyone know this one? I have a 96 GMC jimmy that has the 3 button 4wd selector switch. It is stuck in 4 low. I disconnected the cable between the actuator and the front differential. No codes but number 1 found at the tccm. I don't hear anything from the encoder motor when trying to switch to either 4 hi or 2 hi but do hear clicks from the tccm. the piece that the cable attached to at the differential has some play, but seems like it is mostly out and it has a drip from that area as though the boot isn't holding back the grease. there was a bit of tranny fluid in the vacuum switch in the transfer case, but I think that would only affect going into 4wd and not coming out of it.. unless I am wrong