Hi all, I see I'm not the only one having 4wd problems. Hopefully someone can steer me in the right direction. I have a 2001 Expy. We got snow last night and this morning I was driving on my unplowed dirt road and I saw my 4x4 was engaged while I was in a4wd (4x4 light came on and I had great traction). Fast forward a little while later I notice that the 4x4 light has gone off and I don't have as good traction. I can engage 4wd hi and low, but my a4wd isn't working. I'm not getting any flashing lights or anything. Any idea why my 4x4 h&l would work, but not a4wd?

Thanks

 

IIRC, the 2001 does not have an A4WD light on the instrument cluster. So when you drive in A4WD, you are basically in RWD. When the rear wheels start to turn faster than the front wheels the GEM increases the duty cycle of the TOD (Torque On Demand) electronic clutch inside the transfer case, which adds power to the front wheels. I *think* that may turn on the 4x4 lamp, and turn off the lamp when power is no longer needed to the front wheels. Can you or someone confirm?

 

Thanks. I think you're right about that and I'm pretty sure I saw the 4x4 light come on this morning when I was in a4wd. It hasn't come on since and I'm pretty sure the 4x4 hasn't kicked in. I live a half mile out on a hilly and windy dirt road, and it snowed last night. I know for certain that 4x4 hi and low work. Though 4x4 hi doesn't seem to kick in unless I'm in neutral. I thought 4x4 hi was on the fly.

 

Confirming!

 

Good! At least I know I didn't imagine the 4x4 light being on.
Could it be the transfer case motor? Shouldn't the 4x4 light blink if the a4wd isn't working?

 

4H doesn't "kick in". You have to shift it into 4H. You can shift from A4WD to 4H or 4H to A4WD "on-the-fly" at speeds below 50? MPH.

To shift into 4L or out of 4L, you need to have the transmission in neutral, the vehicle speed at 0 MPH and your foot on the brake.

Sounds to me that your drive train is functioning as designed.
Do you have an owner's manual?

 

Thanks, but reread what I wrote. The 4wd hi doesn't appear to be kicking in unless I'm in nuetral, and a4wd doesn't seem to be working at all.

 

Sorry for not being clear. I was more confirming the operation of the A4WD system and not the dash light. The 4x4 light will only come on if you turn the switch to 4wd. If the light comes on by itself that's an indication of bad contacts down in the shift motor or a bad 4WD relay pack under the dash.

 

False alarm! We got over a foot of snow the night before last and she's driving through it in a4wd like it's a sunny 70f day out. God, I love this truck!