H2 will not go into the other 4wd modes
 

I have two H2's-an 03' the 4wd works and an 05 that will come out of the normal 4HI setting. With shift lever in neutral, the button will blink on which ever one i hit for 15-20 seconds and then go right back to the 4HI light. No dash sevice 4x4 light has shown up. Heres what I have tried swapping out parts from the 03 that is good.

*checked TREC fuse under the hood and 4x4 fuse under the steering wheel w/ a voltage meter. They are good fuses and have power at both sides of fuse.

*swapped out the transfer case shift motor with the 03. both motors work on the 03', neither work on the 05'

*swapped out the transfer case control module. both work on the 03' neither one works on the 05'.

*swapped out the 4x4 switch module (dash buttons), both work on the 03, neither work on the 05.

not sure what else to check. almost seems as if something is holding the transfer case control module out from sending signal to the shift motor.

sorry, first sentence should read will NOT come out of the normal 4HI setting

No 4x4 system guru's?

Sorry to bring this back from the dead a decade later, but I am having almost the exact same issue. Any chance you’re still on this form and figured it out?

if you went through what he already did and are at the same point then you need to lift all four tires off the ground on a flat surface as the trucks transfercase will need to be manually switched through the modes then remove the transfer case selecter motor see if it actually changes position when selecting modes if it does then get a hold on the shaft on the transfercase and manually cycle through the modes. make sure all 4 wheels are off the ground and the truck is level unless you want to get run over with 6000 pounds. if the module cycles then most likely the electronics are fine and the transfercase is bound up or bad shift fork inside.

I have a brand new shift module and a brand new shift motor.

it absolutely feels like the electronics are getting no power. I’ve tested the fuses multiple times, no lights at all on the dash module, but do get the temp light on the 2TC button for a few seconds.

thanks for that, I’ll get it up in the air

Check the engine ground strap to make sure its there and in good condition. Also with the transfer case motor off verify you can move the shift shaft and manually change the mode.

Be sure to note the position of the shaft and put it back in the same position before putting the motor back on. Pulling the battery cable for 30 minutes then re-connecting can sometimes clear up confusion in the onboard computer systems.