4 button 4wd problems...
InProgress65
12-16-2009, 06:24 PM
I have a 2000 GMC Jimmy with the 4 button "Auto 4WD" option, I believe it's the NP8 transfer case.
I had the trans rebuilt and when i got it home I decide to check the 4WD since the tcase had been out of it. everything worked at first but then I heard relays clicking and the service 4wd light button came on and it was stuck in auto 4wd. I shut the truck off and still stuck in 4wd. I disconnected the battery and when I started it back up it was now in 4 hi. Now i was able to press 2wd and it was fine. Untill the next time i selected auto 4wd...same thing. After a while I no longer had to diconnect the battery, now i just have to shut the truck off and start it back up...back to 4 hi...press 2 hi and it's fine. 4 hi seems to work fine, 4 lo seems to work fine, however, auto 4wd seems to actually be simply 4 hi, not auto. Every time I press auto 4wd the service 4wd light comes on and I have to shut the truck off in order to get it back in to 2wd.
I really dont know too much about 4wd but I'm otherwise pretty sharp around the garage. I'm shure I can fix this IF I only knew what the problem WAS. Could it just be the dash switch?
Please help...
I had the trans rebuilt and when i got it home I decide to check the 4WD since the tcase had been out of it. everything worked at first but then I heard relays clicking and the service 4wd light button came on and it was stuck in auto 4wd. I shut the truck off and still stuck in 4wd. I disconnected the battery and when I started it back up it was now in 4 hi. Now i was able to press 2wd and it was fine. Untill the next time i selected auto 4wd...same thing. After a while I no longer had to diconnect the battery, now i just have to shut the truck off and start it back up...back to 4 hi...press 2 hi and it's fine. 4 hi seems to work fine, 4 lo seems to work fine, however, auto 4wd seems to actually be simply 4 hi, not auto. Every time I press auto 4wd the service 4wd light comes on and I have to shut the truck off in order to get it back in to 2wd.
I really dont know too much about 4wd but I'm otherwise pretty sharp around the garage. I'm shure I can fix this IF I only knew what the problem WAS. Could it just be the dash switch?
Please help...
MT-2500
12-17-2009, 09:12 AM
Yes it could be.
One of first things to check.
Some solder the switch for repair and some replace it.
Transfer case codes will point you in the right direction.
Any codes post back codes.
One of first things to check.
Some solder the switch for repair and some replace it.
Transfer case codes will point you in the right direction.
Any codes post back codes.
InProgress65
01-22-2010, 04:14 PM
UPDATE: Finally got around to taking it in to have someone pull the codes. They looked into it really quickly and dicovered that the trans shop (I'm assuming) forgot to plug the output shaft sensor in. so as soon as I put the truck into Auto 4wd it threw a code because it couldn't tell if the front and rear shafts were turning at different rates
MT-2500
01-22-2010, 04:29 PM
UPDATE: Finally got around to taking it in to have someone pull the codes. They looked into it really quickly and dicovered that the trans shop (I'm assuming) forgot to plug the output shaft sensor in. so as soon as I put the truck into Auto 4wd it threw a code because it couldn't tell if the front and rear shafts were turning at different rates
What was the code no.
Did plugging it back up fixt it>?
What was the code no.
Did plugging it back up fixt it>?
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