I have a GMC Duramax, 4X4, club cab pickup. In the morning, before the truck warms up, I can't engage theXXXXX(neither hi or lo). After the engage light flashes for a few moments, I get a "serviceXXXXX message. The message goes away if I switch to another display.After the truck reaches normal operating temperature, I can engage theXXXXXnormally.What's happening?
Country: United StatesMake: GMCModel: 2500 Sierra 4X4Year: 2007Engine: Diesel
Hi,welcome to Just Answer.I will be happy to assist you with this question today.I will try and assist you as best as possible from here,feel free to ask any follow up questions to my info provided here.From what you have described here this can be caused by a number of different faults,most common can be the 4wd switch assembly itself or the transfer case actuator/encoder motor assembly.What needs to be done is to have the fault codes checked with a scan tool or code reader that can communicate with the transfer case computer.Once the codes have been read out of the transfer case computer then it can be diagnosed as to which component is at fault and then repaired.Most shops and dealers can read out these codes and a local parts store might check them free of charge for you as I have heard of before.Most common is usually the switch assembly or the actuator on the transfer case assembly.Hope this helps, and please remember to indicate that I have helped you today.
GM training and dealer tech for 14+ years. Diagnostics
Hi,I'm just following up with you to see how everything is going. Did my answer help?Let me know,Pete