I was fixing some fence at the bottom of a really muddy hill today and when it came time to go back up i tried to put it in 4x4 and nothing happened. Checked the fuse it was good. there was no noise coming from the transfer case at all and it just worked perfectly last Saturday.

any ideas why its not working? could the switch be bad?


thanks

 

did you try to manually put it in 4x4. Turn the switch and then get out and lock the hubs?

Also sounds like your solienold for the transfer case may not be working, based upon what you are saying.

I would try that and report back.

 

Did the light on the dash come on?

 

Sounds like a bad solenoid to me.

 

The dash light does not come on and i have manual hubs so, yes, i did get out and lock them.


How much does the solenoid cost? how hard is it to replace?

 

I just got done spending 3 days troubleshooting the same problem. I took apart and tested every component and what I found was if the light doesn't come on that the 4x4 module is bad. Changed it for around $160 with next day shipping(online) and everything works perfectly.

The module is located behind the glove compartment upper right side.

 

how do i check this to make sure its the problem? where did you buy the part and what was the part number?

thanks for all the help!

 

If the 4x4 light is not coming on, then the problem is not in the solenoid. All the solenoid does is provide a vacuum pulse to lock and unlock the hubs.

The first thing to do is to check fuses. Go through your owners manual and check anything that has to do with 4WD, engine controls, or anything you think may remotely be involved with any engine or body module system. Don't just visually inspect the fuses, check them for continuity with a meter. I don't know if 2001 used the GEM module to control the 4WD, or if they'd switched to the 4WD control module at that time. And I don't know if they used the GEM, if "GEM" would appear in the fuse panel. But if they did use the GEM, then any fuse for it may be labeled as anything the GEM controls. Door locks, security, 4WD, and some other things I'm not sure about.

Also, I'm not sure if a 2001 has the HEC cluster, but search for "HEC cluster" on here and follow the test procedure. If the test procedure works, it will tell you if your 4x4 light is working and not burnt out.

The most common cause for the transfer case failing to shift is not the computer module. It's is the shift motor relays. The shift motor relays are in the engine compartment, on the drivers side firewall, to the rear. They should be in a box with just two identical relays. Find them and check to make sure their is no contact corrosion, etc. Swap the relay's position. One relay moves the shift motor from 2WD to 4WH to 4WL. The other relay moves the shift motor the other way, from 4WL to 4WH to 2WD. Swapping the relays will often cause the transfer case to shift into 4WD, but not back out. If this is the case, replace the relays.

Another good test is to disconnect the TWO wire connector from the gear motor on the transfer case. Connect a test light between the two wires. Have someone switch between 2 and 4WD, with the key in the RUN position. I don't believe you need the engine running. If you see pulses on the light, then the module and relays are working and the problem is the gear motor.

 

ok i will do this

[/quote]I don't know if 2001 used the GEM module to control the 4WD, or if they'd switched to the 4WD control module at that time. And I don't know if they used the GEM, if "GEM" would appear in the fuse panel. But if they did use the GEM, then any fuse for it may be labeled as anything the GEM controls. Door locks, security, 4WD, and some other things I'm not sure about.[/quote]

i dont think it is because i have never seen anything on this before, but i will check this also

[/quote]Also, I'm not sure if a 2001 has the HEC cluster, but search for "HEC cluster" on here and follow the test procedure. If the test procedure works, it will tell you if your 4x4 light is working and not burnt out.[/quote]

the bulb isn't burnt out because when i turn the truck on the light goes on for a few seconds. Also if the bulb was malfunctioning wouldnt it have still gone innto 4x4? because i only had 2wd when trying to drive out....

[/quote] The most common cause for the transfer case failing to shift is not the computer module. It's is the shift motor relays. The shift motor relays are in the engine compartment, on the drivers side firewall, to the rear. They should be in a box with just two identical relays. Find them and check to make sure their is no contact corrosion, etc. Swap the relay's position. One relay moves the shift motor from 2WD to 4WH to 4WL. The other relay moves the shift motor the other way, from 4WL to 4WH to 2WD. Swapping the relays will often cause the transfer case to shift into 4WD, but not back out. If this is the case, replace the relays.

Another good test is to disconnect the TWO wire connector from the gear motor on the transfer case. Connect a test light between the two wires. Have someone switch between 2 and 4WD, with the key in the RUN position. I don't believe you need the engine running. If you see pulses on the light, then the module and relays are working and the problem is the gear motor.[/quote]

i will also try out both of these.

Thanks for the help!

 

I believe from my research that 99 or 2000 was when they switched over to seperate 4x4 modules.

DOn't go for a module until you check everything with a DMM.

The selector switch is just a resistor to check to see if the resistance changes from 2H to 4H to 4L

Instead of taking apart the transfer case (like I did) and checking the motor and switches I would force the 4H to 4L and 4L to 4H relays under the hood (at least thats where they are in my 03). The module just closes the ground so if you jump the other side of the relay coil to ground you will hear the shift motor turn. I actually did this while waiting for the module because of course no 4 wheel drive and it snowed like crazy. If this works then I would have to assume the module (after checking ALL the fuses in the box with a DMM).

I would just check all the fuses because they is actually 3 or 4 different fuses that feed power to different parts of the 4 wheel drive circuit.

If the motor doesn't turn after grounding then it is either the limit switches, the motor, relays etc and I would test each component.

If it does end up being a 4x4 module pull the glove box all the way down and look up and you will see it on the right side. just take the part # off it as I'm sure it is different than my 03.

And by the way there are absolutly ZERO aftermarket places to get one so find the best dealer price you can. There are a few good ones that support the site so ask around the vendor area.

Anyway just my experience.
Good luck

 

so the bad news i changed relays and fuses and it still wont work.....looks like this is going to get expensive

 

Check each component under the truck.
Thats where I would go next. Pulse the motor and ohm out the limit switches.

 

I know it has been a long time I am at school so time to work on my truck is extremely limited. Yesterday I had to go out to work and with all of the snow i said what the heck and flipped the switch to 4x4 high while i let my truck warm up and scrape off the ice. I got back in my truck and the light was on!!! I was hoping the truck fairy came and fixed my truck. It Didn't! went to drive and it made a real bad clicking noise so i turned it off. after 30 seconds the light went of and i proceeded to drive again only to hear more clicking. so i stopped waited a little hoping it would disengage and started to drive. I took about 5 stops to get it to stop the clicking. once i got home i tried to engage it again to see if it would and it wouldn't.

any ideas? is my transfer case shot?

 

More than likely the 4x4 transfer case switching motor is on it's way out.

 

is there any way to check on this?