flashing 4x4 lights after gear change?

[dreamr]

Ok I know it is the second thread with this issue from me and it is a common enough question at that. But please read on a bit. If you would like to visit the other thread here is the link.

http://www.explorerforum.com/forums/showthread.php?t=128017

The original thread was oriented more to the locker issues which have been resolved and I felt may have been related. Now both I and the guys at Randy's are trying to figure the last oddity out. Hence this post. Please note I have never had any 4x4 issues, and it was operated in 4 lo 2 days prior to regearing.

On friday I had the 3.73 gears swapped for 4.56's. The install was good and the wear pattern on them that I saw today was perfect Well at least according to the pictures in the book

A few miles from the shop my lighted rocker switch (brown Wire Mod) indicating the control track system completely blinked out. Odd I thought it usually dims way way down, but not out. I look back to my dash and see the notorious flashing 4 lo and 4hi lights. 6 flashes per cycle. I attempted to shift into 4x in the next parking lot and got no response form the vehicle in either range. Later that night the battery was unplugged for a bit and everything was working normally again. Including shift to 4 low. I went for a drive and the lights started kicking out my control track. Tested in a parking lot I found that I was able to shift into 4hi and it was really in4 hi. 4 low would not engage, and the auto setting was only functioning as a 2wd when spinning the tires in gravel. I should also note that upon startup and for the first say ten miles auto functions normally then out and blinking lights.

There was also one odd test where it shifted into 2? low

My first thought was what did they forget to plug in?????
I inspected everything several times, I had a buddy inspect everything, Randy's R&P examined everything. It's all plugged in appropriately. Hmmm????

Searching on the internet provided me with three potential candidates for error.
Shift Motor
Hall-Effect Sensors
T-case nedds a flush and fill

I figure I will go ahead and pull the shift motor and sensors for cleaning, but I just don't buy the coincidence. Why would it just happen to go out within minutes of regearing.

That leaves me with a question to those more knowledgeable about the ford explorer than me or the guys at Randy's. I want it fixed, and they would really love me to answer the question for them as well. I was the first late model second gen explorer they have dropped gears that low in. If another comes their way, they want to be able to offer more help than they could with me. Which is commendable I suppose, but doesn't help me right now. LOL

Anyway here is my poorly phrased question.
Could these lights and the disabling of auto be the result of a very confused computer due to the lower ratio?

I believe that on the earlier explorer's there was a VSS in the T-case which monitored a few things in addition to MPH. Often times this is responsible for concerns when regearing. On the newer x's with control track I believe there are two speed sensors 1 for each driveshaft that monitor their rotating speed. Could it be that these sensors are just utterly baffled by the 30% increase in driveline speed? And as a safety measure they are cutting off auto mode and denying access to 4 low.

On these control trac t-cases the shift motor only shifts to low as high is technically engaged by the computer regulated clutches. Therefore when the switch is flipped the already locked in front end activates, but the computer does not feel up to the task of regulating the auto system with these new ratio's.

Does any of this make sense, or am I just barking up the proverbial wrong tree while my shift motor sits there begging for a rebuild?

 

[dreamr]

Hmm the rear hall-effect sensor was clean , the front driveshaft hall-effect sensor was icky. It looked like it was a dull metalic grey color, and it was pretty thick in a couple spots. Ya know what color it really is? White

The t-case fluid smelled fine, but was a more translucent then transparent, but just looked old rather than bad or contaminated. I filled it drained it and filled it again, I can't really get it all cleaned out untill i can use the 4x4 for a bit then I'll change it out for synthetics.

Also just cause it amused me. I called the local dealership and told them my story hoping they had input. It took about ten minutes to make the tech understand that yes indeed I said 4.56 gears. He talked to others in the shop and they were clueless. I at least expected them to tell me about the TSB they have for the shift motor and the h-e sensors.

Anyway back to the shift motor teardown. I don't really want to cut the brown wire back there, so I set myself up a work bench under the ex at about the max reach of the wiring harness. Tight, but enough room to prop yourself up on your elbows and work. Any way I will update with my results later

 

[dreamr]

Hmmm nobody has any guesses or suggetions huh.

Anyway to update the thread.
Shift Motor and Hall Effect sensors were removed and cleaned. The shift motor once taken apart was in great condition, though I cleaned it anyway. The t-case was also flushed and filled. And lastly I checked all fuses, relays, diodes, etc.............. And yes I had the battery unplugged when doing the t-case stuff, so the memory is clear

My results????? I have the same damn problems. All that work did absolutely nothing. So with that said and all of the standard answers to this question tried and found to be ineffective, Who has some clue??????

Or maybe a simpler question. There are several people on here with 97-00 X's. When you regeared did this happen to you?

Come on people help a guy out.......please I want 4x4 back!



OK, so I just called a different ford dealership and the guys first response is yep them speed sensor are damn confused. He told me to go find myself a custom computer tuner and they can adjust the reps per mile to get things back to normal.

He said that since these sensors are getting a reading that does not make sense to them, the computer will not allow the use of auto or 4 low as the computer feels it could be dangerous to the system. I asked about 4 hi and he said that is a little different. The vehicle is alway engaged in high, what makes the difference is there are clutch packs in the t-case that moderate the amount of torque going to the front (auto) When 4x4 high is activated it apparently bypasses the cpu and directly engages a relay to create the 50/50 power split. In away it is running in cripple mode he said.
Guess knowing that I will at least have 2hi and 4hi if something burns up one day is good.

These dealerships often blow smoke out their rears, so does that sound accurate to y'all?

 

[TPLYNCH]

If you mentioned this, I apologize in advance as I just skimmed thru your posts.....

Did you disconnect the battery to reset the computer after you did the change??? If that doesn't work, then the GEM may need to be reflashed to get it to learn the new setup. As for your dealers, I think the last one actually has the general idea and wasn't steering you wrong.

 

[dreamr]

Thanks for the response TPLYNCH

I did indeed disconnect the battery after the change as well as during the time I was working on the t-case stuff.

When you mention reflashing the GEM, I am wondering if by having my tuner programs adjusted for the gear change this will also resets this module to allow for the new ratio?

Second question. I have seen mentioned in related posts that there is a reset for the GEM in the rear quarter panel of the vehicle. Is this true of 99 up Explorers as well (all the posters were first gen). I looked, but couldn't find any modules with a button in the jack storage area.

I mailed off my tuner to Bama Chips this morning, so if that (computer files) is where the problem is at hopefully it can be corrected soon.

Once again thanhks for your input, I have been waiting for you, Brain, and Glacier to chime in.

 

[Jefe]

I had the 6x flash problem. But I don't recall it happening just after either regearing (to 4.10s or to 4.88's). I bought a new hall sensor and replaced one of them, and then swapped out to the other when that didn't change anything. But my problem was fixed just by cleaning the hall sensors. they were both covered in fine metal shavings, and the fluid would go black after just 1500 miles, and shortly after that my T-case wouldn't hold in 4wd. I assume the clutch died. So I replaced it with the Atlas and never looked back

EDIT: Shortly after regearing to 4.88's I installed a Superlift Truspeed to adjust my speedometer. I don't remember if my t-case started crapping out before or after that.

I also never recall it not shifting between low and high when I had this problem.

 

[dreamr]

Thanks for the reply Jefe. I was hoping to hear from some second gens with low gears, but now you make me fear that I actually might have a mechanical issue

I am kinda waiting to see if the tuner "re-educates" the system before I start buying parts. I have cleaned everything that should be related with no results. I am still curios about the GEM reset i mentioned in my previous post here. Anyone??????????

Of course I made no progress last night in trying to correct the concerns. Really I just tried to stay out of the garage so we had the 114th daily mini rockcrawling championship in the house instead Man I desperately need to repaint a couple of these after the rollovers on the new course.

 

[TPLYNCH]

I'm stumped. Have you rechecked the wiring for your brown wire mod? Fuses/relays?

Tuner - is that your computer chip for the motor? Don't think that will effect the GEM, but I could very easily be wrong.

 

[dreamr]

I'm stumped. Have you rechecked the wiring for your brown wire mod? Fuses/relays?

Tuner - is that your computer chip for the motor? Don't think that will effect the GEM, but I could very easily be wrong.

I am stumped too.

The brown wire mod was put in over a month ago, and there have been no issues. In addition to that when the vehicle is first started auto works properly, though still no 4-low. Now even after the lights flash and auto cuts out if I engage 4-hi the brown wire switch lights up. Going with that I believe it to be fine, though I have not pulled the radio bezel to physically inspect the wiring.

All under hood and interior fuses, relays, and diodes were all tested.

The tuner is indeed my "chip" I am hoping that the control trac system is confused, just like my transmission shifting and speedo, but we will see in a few days about that particular theory.

 

[TPLYNCH]

Just out of curiosity, do you have cruise control? Does it work? If not, a shot in the dark could be the brake switch. If the system doesn't "sense" your foot on the brake, won't shift into 4Lo....

 

[dreamr]

I do not have cruise, but I wondered if possibly the brake sensors in the hubs had been disturbed. From appearances everything is plugged in correctly, but that does not mean anything.

 

[TPLYNCH]

Do you brake lights come on? I'd check the switch on the brake pedal just to be sure.

 

[Jefe]

Do you know someone with a scanner? With my scanner software I can check what codes the 4x4 module have set. That way you'd know exactly what the 4x4 module was saying was wrong rather than the guestimate from the 4x4 lights blinking.

 

[dreamr]

TPLYNCH
My brake lights are operating normally as is my brake system including the ABS that saved a poor little ricers superwing today. I will go root around and see if there is anything to see though. I have to clean up my locker wiring under the dash anyway, so I'll be in there this eve.
....................................................................................................

Jefe
I don't know if the OBDII port will also give 4x4 codes, but I did scan for error codes and all I was getting was that an anti-theft something or other had been triggered. Probably from using my non computer-chipped spare key to turn the ignition on to check electrical connections.
? How did you fool your computer to allow the running of the atlas and the swapped in front axle? I'm more interested in the atlas ?, but shhh don't let my g/f hear that.

Also for Jefe when you ripped that front IFS out or pulled it for maintenance/mods, what all was plugged in that would have to get moved to re-gear the axle?
I know you have a write up in here for it's removal, but sadly I haven't got around to reading it all yet.

.....................................................................................................
I just got a PM from Doug and my flasher is on the way all re-programmed. Perhaps this will help with the lights, if not I guess I start replacing things Getting the flasher will also allow me to use it's scanner features again to make sure no codes have appeared since Monday.

Does anyone have a link to the test procedures for the GEM (which is behind the dash in 2nd gens), hall-sensors, the shift motor, and the dash switch? If it is not in the tuning it's got to be in one of those parts. Right??????

And lastly thank you guys for all of the ongoing support! I know this is one of those common and annoying posts, but this has me baffled and I need the advice.

 

[Jefe]

Yes, you would read the 4x4 codes through the OBDII port, but you have to have a scanner that will talk with the 4x4 module, as it is separate from the PCM.

No electrical mods are required for the Atlas. Yes my 4x4 lights flash because there are no hall sensors or shift motor anymore, but that was easily fixed by pulling the bulbs. And once in a blue moon the OD light would flash because it thought ratios were wrong while I was in low, but after a restart that would go away.
Same deal with the front axle. ABS has a hard time w/o front sensors, but you just pull the bulb.

As for disconnecting electrical while regearing the front, there shouldn't be anything, except for maybe the ABS sensors.

Oh, I've got a good question now. You put a locker in the rear right? (checking) An E-locker so it replaced the carrier. Did they somehow keep the toothed ring in the rear diff for the rear ABS/VSS hall sensor? If you disconnect the two front ABS sensors do you still have speedometer? I already had the Atlas by then, but I know my PCM & ABS hated not having the rear sensor, as it has to use the two front ABS sensors for VSS.

And a stupid question. You know that both axles were regeared with the correct gears? When it works in 4 high, it seems to work correctly?

 

[JoshC]

Well i can't add much but i can say that when i went to 4.56s i had no issues at all.

I don't even recall my 4wd lights flashing when i switched to a manual case.

 

[dreamr]

Oh, I've got a good question now. You put a locker in the rear right? (checking) An E-locker so it replaced the carrier. Did they somehow keep the toothed ring in the rear diff for the rear ABS/VSS hall sensor? If you disconnect the two front ABS sensors do you still have speedometer? I already had the Atlas by then, but I know my PCM & ABS hated not having the rear sensor, as it has to use the two front ABS sensors for VSS.

And a stupid question. You know that both axles were regeared with the correct gears? When it works in 4 high, it seems to work correctly?

They kicked me out of the shop so I couldn't watch all of the install. However when I returned for the grounded out wires in the locker. hey found that the problem was the wires getting crushed up against the ABS ring, so I guess my answer is a "I think so". I have not tried unplugging the ABS sensors to see what happens, but that may be an interesting experiment.

As to the latter, it's not a stupid question for I wondered that myself. It does seem to work properly in 4 hi though I haven't been off pavement to test extensively. Also when I first start up it stays in auto for the first several miles before the brown wire rocker light goes dark and the 4x4 lights start their flashin'. During these first miles it operates normally as well. Of course I never have got it back into low except for the first night after this started.

 

[Premier]

Time for a swap! 1354m baaaaaaby.

 

[dreamr]

Time for a swap! 1354m baaaaaaby.

Shhhh

 

[dreamr]

Hmm I've been to busy hanging out on here to go work on the truck to much

But I did read the Eaton Install instructions and it does mention reinstalling the abs/speed ring as they call it. So At least that is likely not our culprit. I noticed a electrical connector on the dif I checked as well to make sure all was tight. What does that connect too?

Still procrastinating laying on the floor under the dash to work on wiring and check those brake sensors.