Need help - 4x4 mode switching problem

[Fulwood]

I just bought a 97 Explorer XLT Control Trac 4WD. I didn't have an opportunity to test 4 Low. The previous owner indicated everything worked but it shouldn't be engaged on pavement and we were far from any mud. Nice clean vehicle with extensive records so I bought it (along with his story), got it home, tried 4 Low, and nothing. No indicator light, no clunk, clank or any other indication that 4 Low works.

I bought a Hayes Manual but it had no useful information. I read the Owner's Manual again to make sure that I was following the correct steps. I tried to find the same problem here on the forum and couldn't find a very good match. BTW, I don't have any flashing 4x4 dash lights indicating trouble.

If the switch is moved from 4 Auto to 4 Hi and left there a few seconds the 4 Hi light illuminates, however if the switch is moved from 4 Auto directly to 4 Low without pausing a few seconds at 4 Hi, neither light illuminates. If switched from 4 High to 4 Low, the 4 High light stays lit and the 4 Low light fails to illuminate. Bulb is good because both the 4x4 lights always illuminate for 2-3 seconds on starting the engine. I listened everywhere but can hear no relays clicking. I checked all the fuses. I can't hear or feel the shift motor or anything operating during switching of 4WD modes.

I'm assuming 4 High works & 4 Low don't. I'm guessing the switch, relay, or the shift motor thingy. I was hoping .... Oh Great and wonderful Gurus of the Explorer Forum that yall might save me some work tracing down the gremlins before I start tearing it apart. What is the most likely cause? Where are the associated relays found?

Thanks in advance.
Donnie
Macon, Georgia

 

[James909]

I'm assuming that you have the transmission in neutral and your foot on the brake, right?

 

[Fulwood]

I'm assuming that you have the transmission in neutral and your foot on the brake, right?

Yes Sir. Tried backing up and pulling forward. Even tried driving around the block and trying to get it in 4L again in N at stop sign. No luck.

 

[oplitic]

Just to make sure, there are the steps I do:

*Hold the brake, put it in 4Hi
*Wait for it to click in and the 4Hi light is on
*Make sure it went in by moving back and forth (probably only need to move forward)
*Make sure it's in neutral, foot still on the brake
*Switch it to 4Lo
*Wait for a click and 4Lo light on
*If it doesn't engage, sometimes I put it in drive, move some, then back in neutral and switch between 4Hi and 4Lo, works fine for me this way

Maybe try that if you haven't tried it that way? Just trying to throw something out there for ya.

 

[joecrna]

Can someone move this to the drivetrain forum? He might get more of a response.

 

[dnice3183]

Im having the same problem with my 99 xls 4x4 hasn't worked since i bought it 4 low light doesn't flash or anything has anyone posted any suggestions to this problem on any other threads?

 

[Fulwood]

Im having the same problem with my 99 xls 4x4 hasn't worked since i bought it 4 low light doesn't flash or anything has anyone posted any suggestions to this problem on any other threads?

I searched the forum and found several similar threads but nothing that match exactly what mine is doing. Most were about the lights flashing (which is indicative of a bad sensor or something) or about earlier model years with a bit different system. Just hang on a while. Someone here will likely have an answer for us sooner or later.

 

[gijoecam]

I notice it's an XLS... Manual or automatic transmission? If it's a manual, you must be stopped, with your feet on the clutch and brakes. If it's an automatic, you must be stopped in neutral with your foot on the brakes.

If it's not shifting, without hooking it up to an NGS to see which input is missing, it's a guessing game at best. For an automatic, the DTR sensor could not be telling the GEM it's in neutral, or the brake on-off input might not be getting the signal from the brake-on-off switch... It's tough to know for sure.

 

[dnice3183]

It has a manual transmission. Whatever Fulwood's problem is mine also he derscribed it to the T if i switch from auto to 4hi the light comes on after a few seconds if i switch it 4lo from 4hi the 4hi light stays on but if i switch from auto to 4low nuthing lights up could it be my shift motor even tho my 4hi still works or are there any other rerlays out there were missing? By the way checked all the fuses and beat on the shift motor still nothing. Im open to any suggestions lol Thanks guys im new here!

 

[gijoecam]

Hold the phone... Are you stopped, in neutral, with you feet on the brakes and clutch?? For a manual, it needs the clutch input in lieu of the transmission range sensor input so that it knows you're stopped and the transmission is not trying to put power to the transfer case input.

-Joe

 

[dnice3183]

Yep stopped with foot on the brakes and the clutch to no avail...

 

[Fulwood]

I notice it's an XLS... Manual or automatic transmission? If it's a manual, you must be stopped, with your feet on the clutch and brakes. If it's an automatic, you must be stopped in neutral with your foot on the brakes.

If it's not shifting, without hooking it up to an NGS to see which input is missing, it's a guessing game at best. For an automatic, the DTR sensor could not be telling the GEM it's in neutral, or the brake on-off input might not be getting the signal from the brake-on-off switch... It's tough to know for sure.

Mine is an Automatic transmission. (And Dnice3183's is a manual. Does that tell us anything?)

What's an NGS, something only the Ford Dealer has?

 

[joecrna]

Yes, expensive and difficult to use correctly. Finally had to give up and go to Ford recently with my own TC issue. Joe, how can we rule out the shift motor for these two?

 

[gijoecam]

Yes, expensive and difficult to use correctly. Finally had to give up and go to Ford recently with my own TC issue. Joe, how can we rule out the shift motor for these two?

If it was trying to shift and failing to, the system would recognize it as failing to shift. What I suspect is that it's not getting the proper inputs to the GEM, and, therefore, not even trying to shift. Otherwise, it would tell us that.

Unfortunately without the NGS or WDS system to view the GEM PIDs (Inputs and outputs) there's no easy way to know why the system's not shifting.

-Joe

 

[budwich]

well, one thing that you should do is pull the switch and make sure it is working. It is a simple resistor bridge that is used to tell the GEM what you want to do... so there needs to be 3 "distinctive" resistances. If it is fine, then my next guess is that your shift motor connection isn't working. The "easy" thing to do is take the motor out/off and try the switch again and see if the motor moves.... BUT be careful as there are specific positions that the motor shaft / cam have to be in to put the thing back together.... search for thread on testing the motor.

 

[Fulwood]

well, one thing that you should do is pull the switch and make sure it is working. It is a simple resistor bridge that is used to tell the GEM what you want to do... so there needs to be 3 "distinctive" resistances. If it is fine, then my next guess is that your shift motor connection isn't working. The "easy" thing to do is take the motor out/off and try the switch again and see if the motor moves.... BUT be careful as there are specific positions that the motor shaft / cam have to be in to put the thing back together.... search for thread on testing the motor.

Thanks Budwich. I checked it and it seems to be good. The way I figure it I have now eliminated one of the possible 36 switches, modules, relays, or wires that be be at fault. I'll be so glad when I get my Bronco restored!

________________________________

Ford's idea of progress:
Instead of reaching down and moving a lever, reach up to turn a switch
(either of which even my 60 year old wife can do with little difficulty).

What my 1997 Ford Explorer uses to change into 4WD
assuming all of them work (which they don't)

Mode Selector Switch
Shift Motor position plate
Shift Motor
GenericElectronicModule
TorqueOnDemand relay
TransferCaseClutch relay
TransferCaseClutch
Front driveshaft speed sensor
Rear driveshaft speed sensor
TR (Transmission neutral) sensor
PowerTrainControlModule
AntilockBrakeSystem module

The cost of all these components that might need replacement is over $2000 on the Explorer.
Not counting the Ford Dealers diagnostic computer expense and their mechanics labor cost.

The odds of you guessing which one or combination of components or wires or grounds are defective:
1 in 1,521
--------------------------------------------------------
What my 1978 Ford Bronco uses to change into 4WD
assuming you can't bend a 6" long 9/16" diameter steel rod with just your right hand (which you can't)

Shift Lever

The cost of all the components that might need replacement is $20 on the Bronco
The odds of you guessing which component is bad: Pretty Damn good.

 

[budwich]

Nice lament and I feel for you but not sure how it will help you solve the problem. Maybe the post should be "what Ford did wrong with 4x4 activation" rather than "help...". Anyways, I would still remove and test the shift motor as a next step. Most problems can be solved by going methodically about things without going thru the "1521 odds" or spending "$2000". good luck

 

[Fulwood]

Nice lament and I feel for you but not sure how it will help you solve the problem. Maybe the post should be "what Ford did wrong with 4x4 activation" rather than "help...". Anyways, I would still remove and test the shift motor as a next step. Most problems can be solved by going methodically about things without going thru the "1521 odds" or spending "$2000". good luck

Oh, I know it won't help. I didn't mean to come across as being negative. I was in fact seeking help, not a place to complain. Having never owned an Explorer, I just came to the realization that despite reading two maintenance books and tapping into this great forum resource and not being able yet to solve the problem that these are very complex vehicles.

With that in mind, I was just trying to say in a humorous way that with so many things that could go wrong one must be a pretty good mechanic with a lot resources and spare time on your hands to troubleshoot them. I was attempting to warn future forum readers with similar problems that unless they are good experienced mechanics it would likely be wise to take it to the dealer for diagnosis before they undertake repairs.

I'm not trying to cut down Ford or the Explorer. I love Fords enough that I have five of them. So far, I just love and trust the simplicity and ruggedness of my big old overbuilt '78 Bronco more than I do my newer Explorer. I'm not nearly ready to give up on it though. I look forward to working on it, modifying it, and improving it with the help of you fellas.