'01 MS 4wd won't engage
 

I just bought an '01 Montero Sport and I THOUGHT the 4wd was working but NOPE. I can shift from 2H to 4H and 4L with no problems as far as the shifting goes but no lights show up on the dash and it is NOT in 4wd. I've tried this after driving in 4H for a bit, etc. I have to assume it is something vacuum or electrical because the differential isn't even getting the chance to engage but I have no clue where to begin the diagnosis. HELP!

Could be the vacuum solenoid, or the front differential engage switch.

Now giving Code 25
 

I took the MS to my mechanic since the rotors needed to be turned anyway and had him check the 4wd. One of the vacuum solenoids was bad (there are two plus a switch in the vacuum system) so after replacing it we now are getting Code 25. He says this is a switch in the transfer case. He recommended a transmission shop for this task - am I going to be in for a fortune here?!?!?! Anybody have experience with what this costs and how difficult it is? I guess I'll find out tomorrow when I call the place but I'm a bit leery. I've spent some serious cash AFTER buying this vehicle on tires and brakes (knew I'd have to do that) and now the 4wd. I like the MS but she isn't cheap so far! :)

That sounds like the vacuum solenoid valve to me. I would not touch the transfer case just yet. :)

vacuum soleniod vs. vacuum solenoid valve
 

He replaced the vacuum solenoid that tested bad yesterday; is this the same as the vacuum solenoid valve or something different? Best I can tell, there are two solenoids that connect to some sort of motor or actuator - one of the solenoids is what he replaced (he called it a 4x4 clutch switch on the invoice)...????

Sorry, should have made it clearer. The one I was referring to is located on the top of the front differential.

Hi Myersbr2

have you worked out what the problem was yet? i have exactly the same problem on my 04 Mitsubishi Challenger (Montero Sport). I can easily shift the gear stick from 2WD - 4H - 4L but no lights dispay and im 99% sure 4WD is not engaged. Sounds like what the other members have said is on the money. If anyone has any other suggestions would greatly appreciate to hear them.

Cheers, Steve


2004 Mitsubishi Challenger LS (Montero Sport) 3.0 V6 Auto

Seems to be working a bit better now
 

After replacing the vacuum solenoid the 4wd seems to be working, both 4H and 4L. Occasionally I get the ABS light coming on as well but mostly it is working. If continuing to play with it doesn't fully fix the issue I know the next step will be the switches on top of the differential.

As far as testing the solenoids, my mechanic just took a vacuum pump to them and played for a while. The article I'll link below was very helpful as I looked at it and gave my mechanic a bit of info he didn't have. Hope that helps!

http://4wd.blogeasy.com/article.view...ticleID=318776

Thanks for that myersbr2, that was very helpful. Im pretty sure that the vacuum solenoid is the issue. From your experience are they very expensive to replace? Not in a rush to get it done as i wont be using the car offroad for a while. Thanks again, and the link was really good