I have this exact issue on my `98 XLT. What exactly is a "HALL" sensor, and where is it located? I might try to replace this sensor first like CNTHOR did...

 

hey there people, i changed my control module (the one just to the left behind the radio with 50 wires conected to it) back to the original one and i got my 4x4 back but only in hi. my door chime, and vanity mirrors even started working. i think im going to wire it in to a 6 prong 3 way switch. if i can get away with it.

 

WOW..lots of people with the 4x4 flashing lights problem. Me too. 1997 Sport, Control Trac. 2 year old rebuilt transfer case from very reputable shop that FORD DEALERS use. Sounds like there are several items that could be the fault, or a combination. My lights flash every minute or two, exactly 6 times!
PROBLEM 1:
Lately, the unit will try and engage after depressing and letting out clutch and the dash selector is in NORMAL!. The lights DO NOT FLASH when this occurs! The way I see it, the motor is getting a false signal to try and engage from somewhere. The one post on the HALL sensor seems to be the most logical place for me to start. Wht the lights don't flash when this occurs is beyond me...you would think they would.

If I understand it correctly, the HALL sensors tell the control module when the axles speeds don't match (indicating wheel slippage/etc), and send a signal to the shift motor to engage the 4X4. This could cause 1 of my problems, unit tries to shift into 4X4 with dash selector in NORMAL.
PROBLEM 2:
Dash lights flash 6 times exactly every few minutes while driving at highway speeds in 5th gear, with no detectable attempt of the unit to engage into 4X4, may also be the HALL sensors??? I can push in and release clutch with lights flashing and nothing happens and lights will continue to flash unit the count reaches 6.

Let's see, the possibilites are???...Sensors: HALL sensors on each drive axle. Speed sensors maybe?? - 1 in transfer case - 1 in rear axle.
Drivers: Selector switch in dash.The computer. The motor. Displays: The dash lights. Did I leave anthing out?

Oh well, I am headed under the car now to try and resolve this problem. I will post any positive results.

One more thing, this car also has that speedometer dropping in and out problem! Replaced the speed sensor in transfer case, no help...removed unit checked good too.
This problem has been there way longer than the 4x4 problem!

 

have the same problem with the flashing lights in my dash. really do appreciateall the great info, have no good place to work on my truck so i have to take it to the dealer, but now i am informed on possibilitiesand hopefully wont get took. thanks again for all your help.

 

I have found on my 1997 EXP Sport 4x4, that there are 2 sensors on the back side of xfer case. 1 just under rear drive shaft output flange and easy to see. another just above the shift motor, and very hard to see. these pick up front and rear wheel speed to for the 4x4 feature. There is a 3rd sensor in the rear axle, and as I understand it, this is for abs brake system only, not the 4x4.

 

I seem to have fixed the problem on my truck. I changed the fluid in the transfer case, and took out the sensors and wiped them off. After changing the fluid, the lights stopped flashing, but I could not get the transfer case out of 4 Low (yeah, great). I ended up replacing the transfer case shift motor, and I have not had a problem since. Everything appears to be working as new. The fluid was pretty nasty, so it makes sense that it could influence the sensors in the case.

 

After having this problem and reading some of the info available I wne t about the following task. First and with much reluctance I went to the Ford dealer since the HAll sensors are a FORD only part. They have also gotten quite pricey.....$60.00 for the front and $70.00 for the rear. Now for those who dont want to throw money away on what is an expensive experiment....I say this because the dealer has no absolute fix for this......its a step by step repalcement of parts which can add up to quite a bill.
It is a simple known fact that the hall sensors fail.......sadly you cant tell which one and as one knows.....these are electrical items which are not returnable/refundable.
So.....let me tell you what I did......take a little excursion to your local salvage yard/u-pull it yard if a vailable. The entire shift motor and both sensors will unbolt and un-plug. A fairly simple removal that can be done under the vehicle. Swap out the entire assembly for yours....the only wire needed to splice will be the brown wire which goes into the tranfer case.
This solved my problem as it eliminated multiple possibilites....poor conduction in the motor and the guesswork of which sensor...front or back. Cost....about $20.00 and perhaps 30 minutes to do the swap.
two important things to note....if your getting the used part.....find a vehicle that was damaged in a collision so that it was probably running ok prior to its accident. This will usually solve about 90% of the time.....the other 10% involves a possible relay/electrical issues.
Dont let anyone sell you on a transfer case before doing a lot of checking........my blinking lights began some months after I installed a new
tranfer case and found that all the other exteral parts were swapped over.
Hope this helps
PS: my 97 Explorer has 196,600 miles and there is no reason to think it wont go another 100,000. They are great vehicles as long as properly maintained.

 

I have a 2000 Ford Explorer 4x4.
When I start my car the 4wd high and 4wd low lights flash six times, they shut off and flash again for six times again every 2 minutes.
The car will not go into 4wd high or low. It makes no clicks or any sounds indicating its attempting to go into 4wd. and the only time the 4wd lights will go on is every 2 min when they flash; nothing when I turn the **** to engage 4wd.
I have researched this issue online and come up with several possible problems.
Bad speed sensor on the brake calipers
Problems with the transfer case
Faulty TOD
Bad hall effect sensors
Bad GEM module (seems this is a recall part for this model)

The price range for parts to fix this problem range from 20 dollars to 500 dollars and the labor ranges from cleaning a dirty sensor to replacing a transfer case.
I just put new brake rotors and pads on the front wheels and the problem seemed to start the next time I tried putting it into 4wd.
Whats the best way to determine the problem?

 

I had the radio out of my truck,when I put the cluster back in,I got the 4x4 lights flashing 6 times about every 5 minutes. Took the radio cluster out and found that the 4x4 switch had become unplugged.I plugged it back in and it stopped. I don't know how many people this will help, but I figured I would post this anyway,it's worth checking out if you had your radio cluster out.

 

I have the exact same circumstances in my 1998 Explorer Sport 5 speed. It also happened after my brake pads and rotors had been replaced, and now I have the flashing lights and my truck will not go into 4WD at all, low or high. It's stuck in 2WD.

Does anyone have any insight or ideas they could share? I'm curious that the problems for both of us started after the brake pad/rotor replacement. Could something have happened during that process that triggered the problem with the 4WD?

 

Hi there in US.
Well, I have an Explorer 1997 and yesterday started the same problem, the lights 4WDHigh and 4WDLow are blinking every 2 minutes. I read all the forum but I didn´t understand where are the sensors to fix the problem.
I know I´m far away, in Brazil, but I will try to find and fix. PLease help me.
Evair Gallardo.

 

Just wanted to post an update, the transfer case ended up being shot. The fork was bent and the shift motor was completely broken, so we decided to rebuild it and replace the shift motor.

 

Diagnostic Flash Code Information
NOTE: The following flash codes 1 through 16 are On-Board Diagnostic (OBD) codes generated by the control module. If a system fault is detected, the control module will "flash out" the corresponding fault code on the electronic four-wheel drive Malfunction Indicator Lamp (MIL) on the instrument panel. Also, notice that all the codes that can be generated pertain only to the speed sensors, the clutch coil and clutch with the exception of the first flash code.
The electronic four-wheel drive system also includes the brake switch input, Park/Neutral Position (PNP) switch input, one power and two ground lines, along with the E-4WD MIL. The following pinpoint tests include testing on every electronic four-wheel drive circuit and not just those covered by the flash codes. DIAGNOSTIC FLASH CODE CHART
Flash Code Description Action to Take
—Inoperative or Erratic System Errors. Complete Tests AA through DD.
1 Microprocessor RAM (Random Access Memory) access error. Replace Control Module.
2 Clutch connector or clutch coil has discontinuity. GO to Step FF1.
3 Front output speed sensor connector or internal circuitry of sensor has discontinuity. Go to Step EE1.
4 Rear output speed sensor connector or internal circuitry of sensor has discontinuity. Go to Step EE1.
5 Both front and rear speed sensor connectors and/or internal circuitry of sensors have discontinuity. Go to Step EE1.
6 Clutch and front sensor connectors and/or clutch coil and/or internal circuitry of sensor have discontinuity. First see Step FF1, then Step EE1.
7 Clutch and rear sensor connectors and/or clutch coil and/or internal circuitry of sensor have discontinuity. First see Step FF1, then Step EE1.
8 Clutch and both sensor connectors and/or clutch coil and/or internal circuitry of sensors have discontinuity. First see Step FF1, then Step EE1.
9 Mechanical problem that allows clutch plates to slip during clutch engagement (or faulty sensor output signal). First see Step FF1, then Step EE1.
10 Both Code 9 and Code 2. See action for Code 9.
11 Both Code 9 and Code 3. See action for Code 9.
12 Both Code 9 and Code 4. See action for Code 9.
13 Both Code 9 and Code 5. See action for Code 9.
14 Both Code 9 and Code 6. See action for Code 9.
15 Both Code 9 and Code 7. See action for Code 9.
16 Both Code 9 and Code 8. See action for Code 9.
Regeneration (Recovery) of Flash Codes
If the ignition is turned OFF and the code is lost, the ignition will have to be turned ON again to regenerate codes 1 through 8, if the condition or conditions still exist. To regenerate codes 9 through 16, the vehicle must be driven again.

 

I am having the same problem with my 98 Ranger. This thread provides a lot of useful info about the possibilities of the fault. Thanks for the info, I will put it to good use.

 

Hello,

Been experiencing the blinking 4WD light indicator on my 97 explorer. In my case can't engage 4WD. At the same time the 4WD blinking indicator problem started I lost power window and moonroof function. Could be a coincidence, and be two separate issues, but was wondering if the two problems could be related to a single faulty electrical relay. If you still have that front driveshaft HALL Sensor I may be able to put it to use.

Dave