- Dec 13, 2013
- 4
I have done a lot of reading but I am at a loss of how to troubleshoot this. This is like nothing I have found on several forums. Sometimes everything works. Sometimes it switches modes without changing the dial.
Here are some of the weird symptoms. Truck is 2004 Envoy XL 115K miles.
1) Ignition on no flashing or illuminated lights on dial. Turn switch from 2hi to auto 4x4 nothing. Turn from auto to 4HI and service 4wd comes on. When this happens there is no noises from under truck.
2) Sometimes everything works normal. When it works - all lights function and no service 4wd light.
3) Sometimes the mode shifts without changing selection on dial - I think including going into 4LO!!!! Not when moving but when truck is turned off and back on.
4) When everything is working and truck is in park - switching modes 2hi-Auto-4hi will work fine for numerous rounds (can hear actuators). Then if I put it in gear and switch from 2hi to auto it is fine, but auto to 4hi will trip dash light and everything will stop working.
Got a used TCCM that someone claimed was good - still acts the same. Could this be ignition switch? I have had intermittent working cruise control, and one time the truck stayed in acc mode with the key out. How would you recommend troubleshooting this? Any ideas?
Here are some of the weird symptoms. Truck is 2004 Envoy XL 115K miles.
1) Ignition on no flashing or illuminated lights on dial. Turn switch from 2hi to auto 4x4 nothing. Turn from auto to 4HI and service 4wd comes on. When this happens there is no noises from under truck.
2) Sometimes everything works normal. When it works - all lights function and no service 4wd light.
3) Sometimes the mode shifts without changing selection on dial - I think including going into 4LO!!!! Not when moving but when truck is turned off and back on.
4) When everything is working and truck is in park - switching modes 2hi-Auto-4hi will work fine for numerous rounds (can hear actuators). Then if I put it in gear and switch from 2hi to auto it is fine, but auto to 4hi will trip dash light and everything will stop working.
Got a used TCCM that someone claimed was good - still acts the same. Could this be ignition switch? I have had intermittent working cruise control, and one time the truck stayed in acc mode with the key out. How would you recommend troubleshooting this? Any ideas?