Hey Guys/Gals,

It's Quinnman105 (Kevin). Tonight I was running and my Service 4wd light came on. Also when I put the truck in gear it went from 2wd into 4lo. Pain in the *** to get it back into 2hi. Got it back into 2wd. Driving on highway 2hu light is solid and 4lo light is flashing. Then goes off then comes back on flashing then goes off. Any clues

Kevin

 

How fast were you going when you put 4lo on? I think if you're going over 3mph it doesn't kick in, so it flashes and waits for you to slow down so it can go on. I think I discovered something like that with 4hi. I put it on going like 40, (Supposed to go like 25 or slower) and it just flashed and didn't engage.

 

I'm assuming you have the auto4wd option due to the Service 4wd light. The only real way to diagnose this is with a Tech2 or equivalent scan tool. I would start by pulling the TCCM and cleaning the electrical connections.

 

This is what happened. Last night my g/f & I were finishing up xmas shopping. When the Service 4wd light came on. It came on when I was turning into a parking lot. The light was on when we wnt to dinner. When I started the truck theService 4wd light was NOW OFF. We then headed towards her house. She lives near Hartford, CT. When we were leaving the Brass City Mall in Waterbury, CT. I started the truck put it in drive it Jumped from 2HI into 4LO. I didn't touch buttons. I got the truck back into 2HI. When on highway the 2HI light was solid. BUT my 4lo light was flashing. What does this mean?

Kevin

 

its trying to tell you its time to go 4 wheeling it wants to use 4 lo. give it what it wants and go hit the mud. lol

 

I can not find any information that would explain the blinking of the lights. On the Auto4wd models, the only way to diagnose them that I know of is to plug them in to a Tech2 or equivalent scan tool.

 

4lo shifts require neutral, and preferably rolling forward at 5MPH or less.

4Hi can be shifted into at any speed... But it's not reccomended for speeds higher than 45 - 50MPH

 

Mine did this exact thing!

Turns out my switch was faulty, dropped in a new switch and everything runs normally now.

 

Where did you get your switch from? Maybe I should start with that and see what happens. I already had it scaned wit that scan tool. Nothing was found.

 

50 bucks from the dealership, just pop it out of the dash and switch them!

Took maybe 2 mintues.

Edit:

MY Service light came on every once in a while, they couldn't find anything either, till it was light up and I happened to be by there so I swung over and left the truck running and said check it real quick.