09 silverado service 4wd

[bman03878]

went to put in 4wd this morning turned knob to auto and it said it was in but still only in 2wd. after driving down the road for a bit and keep switching dial it engaged in 4wd. then kept swapping inbetween 2wd and 4wd and was fine. then after a while the service 4wd message came on. then noticed the dial was really warm. shut truck off, restarted and the message went out. then i was switching the knob again and it got hot and message came back. is the switch bad seems how it is hot? any info is greatly appreciated.

[Jsdirt]

I had the same thing happen to my '07 when it had barely 3k miles on the clock. Happened leaving work - got the same message, and the blinking light on the dial. Key off, then on, and it went away. It's happened several times over the past 5 years. A couple of times it required 3 or 4 key cycles to get the message to go away. I've got leaky seals in the front diff where the CV axles meet up that started at 50k miles - no idea if that's related or not.

 

As for the dial getting hot - they all do. It's from the background LED lighting. That's the nature of LED's ... even household ones.

[bman03878]

i understand led making dial hot, but my light dial doesn't get hot next to it. the dial and area surrounding it gets almost to hot to touch.

[gmtech4]

the message means the electronic 4WD system has a code stored and needs to be scanned and diagnosed,,,,,no throwing parts at or changing any oil,just get it diagnosed

 

see your owners manual for more info on messages

 

you have warranty remaining right?

[bman03878]

took my truck to dealer. didn't have the scan tool there to check but the service 4wd hasn't been on. my knob for 4wd or rps gets hot as hell. hot enough so you really can't keep your fingers on it. also hot on dash between the 10 and 2 postion above the knob. thinking short in the knob so i changed it but still gets hot as hell. is something sending it to much voltage?

[Jsdirt]

Excessive heat means high resistance - either a faulty switch or bad connection.

 

Who knows what other electronic wonders are back there, ready to fail at a moments notice. Boy do I miss my '72 El Camino ....

 

Sorry I can't give you much more than that. If you're still covered under the bumper to bumper warranty, bring it in and let them fix it.

[gmtech4]

i told you not to throw parts at it ,,,,,,

[bman03878]

govtech4 took truck in to dealer to have a scan done. service 4wd display hasn't been on so no codes appeared. 4wd knob still very hot. truck bumper to bumper warranty is up and didn't really want to spend hundreds of dollars at $95 and hour to trouble shoot. tech said to clean the ground under driver body mount. do you know of anything else i can check? any other grounds or connections that may be bad.

[Jsdirt]

..... do you know of anything else i can check? any other grounds or connections that may be bad.

 

Knowing GM today ... all of them.

[gmtech4]

govtech4 took truck in to dealer to have a scan done. service 4wd display hasn't been on so no codes appeared. 4wd knob still very hot. truck bumper to bumper warranty is up and didn't really want to spend hundreds of dollars at $95 and hour to trouble shoot. tech said to clean the ground under driver body mount. do you know of anything else i can check? any other grounds or connections that may be bad.

 

 

codes dont come and go last time i checked,,,,you are fubared untill you have a code to diagnose

 

its just that simple ,IDK WTF to tell ya now

[bman03878]

so i got the service 4wd light back on while the dealer was open and it showed a code. it was the front differential locking actuator. come to find out gm has a bulletin on these and was replaced inder warranty. had it fixed yesterday and haven't driven it around yet to see if the switch finally stays cool.