O/D off, 4Hi, 4Lo all flashing

[elrothir]

I've got a 1998 Explorer with about 138,000 miles on it. It had been driving just fine. I wanted to test out that it would shift into 4WD before winter. I switched it to 4WD Hi and then 4WD Lo(after going into Neutral). Now, I'm getting several issues:
The 4Hi and 4Lo lights on the dash flash 6 times then go away.
But the 'O/D off' light is always flashing now. And it will shift(roughly) through all the gears before I hit 15 mph. I'm not sure if the 1998 is a 4 speed or 5 speed, but I'm feeling 3 shifts, so I think it's going into 4th gear, but it struggles to even go 45mph(at 3500RPM), so seems like there must be a 5th gear it's not hitting. Also, it seems like if I accelerate quickly, it will only shift into 2nd or 3rd gear. Seems like it misses a gear or two when I do that.

The Check Engine light is NOT illuminated.

I borrowed a code reader from O'Reilly and it threw a P1729 code(4 by 4 low switch malfunction).

I've found a few similar posts, but nothing with all these issues. I'm working through checking the wiring from the 4x4 switch, but not sure why the O/D off light is flashing and basically being in limp mode. Not sure if it matters, but the code reader also displayed a P1000 code and P1260(Theft Detected Engine Disabled). Would that be causing it to drop O/D? Those might be old codes, though. The order they showed on the reader was: P1000, P1729 and then P1260. I have the keys and haven't been driving it much, so not sure why it hasn't cleared the P1260 code.

Any other suggestions on this kind of issue? It was driving fine beforehand, so doesn't seem like it could be the transfer case/tranny... I hope.

Thanks!

 

[Explorer2.0]

Try resetting the computer with an OBD or the battery disconnect trick. We had the flashing O/D light, took it to FORD, paid too much for "Diagnostics" test. They said we needed a tranny. Our '95 only had 60,400 well cared for miles but they tried to sell us a used tranny with 120,000 miles. We asked, "Why not rebuild our tranny?" Their reply... "Rebuild kits are no longer available." One look online and we saw rebuild kits available. We said no and picked up the truck. It was still in limp mode on the way home. We disconnected the battery, waited a few minutes, reconnected and went for a nice drive. That was 6,300 miles ago! The B@$tARD$ at FORD didn't even consider anything other than what their computer diagnostics was reading let alone resetting the on board computer. The whole reason we went to FORD was because we figured they would have better access to answers to all the problems that occured with 2nd Gen Explorers. We've learned more on this site than FORD could ever hope to know!

Good luck!
Team TARDIS

 

[elrothir]

Thanks for the suggestion. I did the battery disconnect and that cleared the 4Hi/Lo flashing, but after driving for a little bit, I still get the O/D Off flashing light. I'll try working through some of the suggestions on that from the other forums. Strangely most of the other ones say people get the O/D Off flashing but no drivability issues. Mine definitely shifts way too soon and runs about 3500RPM at 40MPH. I haven't tried pushing it beyond that. I did try to accelerate really slowly to keep it in the 2000RPM range, but it still shifts hard and early. Check the tranny fluid and that looks fine.

Thanks!
TARDIS??? It's bigger on the inside!

 

[donalds]

Forscan ....free
Obd2 interface
https://www.amazon.com/VDIAGTOOL-EL...417250&sr=8-2-spons&keywords=elm327+usb&psc=1

$13 priceless
You will not be disappointed

 

[elrothir]

I've borrowed a scanner from a few of the auto stores and neither of them pulled any tranny codes.
I did find a ground strap in the area of the drivers side door that disintegrated when I touched it. I replaced it with a piece of regular wire, but it didn't seem to make a difference. I'll try to get the codes read at a shop somewhere.

It's just strange that the O/D Off started flashing after I'd tried to switch into 4WD Lo. Does that make sense to anyone? I still get the 4Hi and 4Lo flashing 6 times whenever I test drive it. Seems like it must be related, but I've not seen anyone else with all three of those issues.

Oh, and the Check Engine Light is NOT illuminated at all.

 

[imp]

@elrothir "We've learned more on this site than FORD could ever hope to know!"

FORD knows, all right, but your Dealer is a piss-poor representative of what a Ford Dealer should be, and do. Outright lying to customers is what puts businesses out of business, especially with the internet's abilities.

Been a Ford owner all my life, long long time, and feel really bad to hear something like your story. Could explain why I never go to a dealer, did once, but that was to buy a reman. transmission. imp

 

[elrothir]

Uh...thanks Imp, but I've not taken this to a dealer to look at yet... I'll never complain about Ford, though. I've had this Exp for 20 years and never had one problem with it. All of my Ford's have lasted me years and never had any major issues(thankfully). So, this one developing an issue after 20 years of great service, I can't really complain. Just wanna get her going again.

 

[kevinspann]

Sounds like it may be stuck in 4 low, or somewhere in between due to the infamous transfer case issues. The input and output speeds aren't what the computer expects so it then flashes the lights as a warning. At least, that's what mine did. Try shifting the transfer case again and see if it will work properly.

 

[elrothir]

Thanks kevin. So, just try to switch it back into 4WD Low? I don't think it's stuck in Low now since I'm able to turn the wheel pretty sharply without it binding up. It seems like it may be stuck in between, as you say, since it all started when I tried to put it in 4WD Low.

 

[imp]

Uh...thanks Imp, but I've not taken this to a dealer to look at yet... I'll never complain about Ford, though. I've had this Exp for 20 years and never had one problem with it. All of my Ford's have lasted me years and never had any major issues(thankfully). So, this one developing an issue after 20 years of great service, I can't really complain. Just wanna get her going again.

@elrothir
Sorry, guess I misunderstood you. imp

 

[Cstoliker]

The transfer case has only 2 positions, Hi and Low range. There is no “in between”

There are many causes for the 4wd lights flashing. It’s a generic fault in system warning. The most common cause on explorers is the shift motor position sensor. The fact that the trouble started when you shifted into Low range only confirms this is likely the problem. Crud will get in the sensor and the GEM won’t know what range the transfer case is in or
which direction to move it so it simply stops and triggers the flashing lights.. If this sensor gets crud in it and fails, you usually won’t notice any trouble until the shift motor moves. It only moves when shifting between HI and LOW range. NOT when switching between Auto and Hi. If your maxing out at 35mph then your stuck in low range. If u need to drive it. Simply remove the shift motor (3 easy access bolts) and manually turn the shaft to “4wd HI” with vise grips or pliers. That will put u in high range and u can drive normally with the dash selector switch in 4wd auto.

FYI. The transfer case only has two selections: Hi and LOW range. If it was in between it would effectively be neutral and you’d have no drive at all. Shifting between 4wd Auto and 4wd HI does not move the transfer case. The electric clutch in the transfer case (TCC that engages your front driveshaft) engages automatically when the wheels slip in “auto”, and all the time in 4wd high and LOW. This is controlled by the GEM (general electronic modular) via a brown wire. The wire should read 12vdc when in 4wd Hi and Low. In 4wd auto it will read around 8vdc and change depending on front/rear drive shaft rotation in relation to each other. In the event of system fault the GEM may turn off the TCC. Wich would explain the lack of binding when turning. The shift motor only moves when switching between HI and Low range. And like an parking brake, the less it’s used, the more likely it won’t work.

The 4wd system is remarkably simplistic. They used old reliable tec and replaced shift levers with electric motors and and electronic clutches. The shift motor’s position sensor is mounted on the back of the shift motor and consists of two logic “on-off” limit switches (like toggle switches) that turn on when the motor reaches its desired position. The position switch’s are incorporated in the motors housing and can be replaced separate of the motor. The reason thease fail so often is their location. There is a seal around the transfer case’s shift lever. With age it will begin to seep a small amount of gear oil into the switch which blocks the connection.

 

[elrothir]

Thanks cstoliker. I am able to drive it over 35MPH, but it runs about 3500RPM at 40MPH. Would the shift motor position sensor also be causing the flashing OD Off light?
I replaced the passenger side ground wire tonight since it disintegrated when I touched it. Then I pulled the speed sensor from the rear axle and cleaned it off. But it still shifts from 1st - 4th before I hit 20 MPH and then will start flashing the OD Off light. I also tried switching it to 4Lo, but that didn't seem to have any effect. It did whine a bit when I'd turn, but not too bad and definitely didn't feel like it was in 4Lo. The dash lights don't even show that it's in 4Lo or anything. I'll try to pull the shift motor and make sure it's in 4Hi. And I'll try to find that sensor and clean it up and see if that works.

I do notice that if I manually push the OD button, the RPM's will jump, so it seems that the OD selector works and isn't stuck.

Thanks for the suggestions!

 

[Cstoliker]

I’ll run some rpm experiments with my Truck in hi low range with OD on and off tomorrow. I have a 2000 with 4.10 gears and a 5 speed. May not be the same but it should give us an idea.
The shift motor should not effect the over drive. But I have seen some other things set it off like overheating, low trans fluid and unknown electronic gremlins. To be honest, I’m not as knowable about the OD system. I replaced the valve body gasket on my transmission to fix the 1st/reverse solenoid and haven’t had to mess with it beyond that.

The position sensor is under a larger round plastic plate. It’s really not serviceable unless you cut around the plastic with a dremel and apoxy it back together. I ran my 95 without a shift motor for years.

I just another thought. I have 5R55e transmission. Its not a true 5 speed. Ford employed some electronic wizardry wich combines 2nd gear and over drive to create a virtual 3rd gear. If you had this transmission and the OD mechanically failed due to a servo or something you would be down to a 3 speed (1st, 2nd and 4th). If it’s a selectable overdrive issue you’d have 1st, 2nd, 3rd and 4th with no OD (or 5th). This only apples to the 5R55e transmissions though.

 

[gmanpaint]

3500 rpm in what gear? OD on or off? If in OD, your in low range still.

Please take the shift motor off, and look at which mark, the selector is pointing to. Takes 5 mins. Take a picture of it, and share it here.

 

[elrothir]

gman, I *think* it's in 4th gear. When I start it up, no lights are flashing and I haven't pushed the OD button, so I assume Overdrive is on. As I start driving, before I even get to 15 MPH, I can feel it shift 3 times, so I assume I'm in 4th gear at that point(unless one of the shifts is a downshift, but not sure how to tell about that). As I accelerate, the RPM's climb and I feel like I'm really straining her to get her to 40-45MPH. So, she's running about 3500RPM at 40-45MPH. If I push the OD button at this point, the RPMs will jump to just over 4000RPM and it feels like she decelerates. Not sure if that tells anyone anything.

I'll pull that shift motor tonight and post a pic. Not sure if they're all related, but they started at the same time.

Thanks!

 

[gmanpaint]

Yeah, your still in low range.

The lights are all flashing because the transfercase shifting is jammed. The computer will shut power off to the shift motor, and it sees the switch and shift motor position are not lined up, and throws it into limp mode. (6 flashes)

This is one of two things:
1) The shift motor is jammed. Easy fix, just replace it. Banging on it to get it to free up works sometimes, but the best solution is to replace it.
2) The issue is internal in the case itself. The most popular thing to break, is the nylon tips on the shift fork. When these go, the fork gets jammed on the ramp, and won't let it complete its movement between ranges.

Ok, so now what? Removing the shift motor to see where the indicator is pointing to, tells us exactly what range the case is in. L-N-H is the marks on the case.

Here is what I want you to do.... Once the shift motor is off, and after you take the picture, take some pliers, and try to rotate the indicator by hand. Place trans in N, and have a helper rock the truck a little as you turn. Rocking takes any bind off the drive shafts.

If it turns easily, (a little resistance is expected) it's your shift motor.

If it won't turn, or does turn, but takes a lot of force, it's internal. In this case, drain the fluids, and look for white or copper particles. White is the nylon, copper is the clutch wires. If any copper is found, replace the case entirely. These cases are not worth a complete rebuild, when you can find them used for less than $100 at salvage yards. The nylon tips are an easy, cheap fix, and is worth it.

There is a rebuild thread by Glacier, on the 4405 case in the trans section, (assuming you have the 4405). That thread shows the nylon tips on the shift fork.

The Borg Warner 4405 Transfer Case Rebuild Diary

 

[elrothir]

Thanks gman! Really appreciate the help! I'll check all that out tonight.
Once I remove the shift motor, does it matter what position the transfer case is in? So, does it matter if it's pointing to 4Hi? Or it doesn't matter at all because it was supposed to switch but didn't, so it gave up?
If I move it, do I have to move anything on the shift motor too to get them to line back up?
Thanks again! I'm really relieved to hear it might be, at worst, a TC replacement and not some horrible tranny issue.

 

[gmanpaint]

Your going to want to put it into H range to drive it on the street. If it turns easy, place it to the H (high), and ziptie the shift motor to the frame rail until you can replace (or rebuild) it.

Do not drive it anymore on the street as is. That can cause major damage to other components in the front end.

 

[elrothir]

I think I've got good news and terrible news.
Good news: Got the shift motor off and got a pic of the TC position. I was easily able to turn the selector to the H position, so it sounds like it's just the shift motor.

Terrible news: Took it for a little test drive with the TC in H position. Drove it to a grade school parking lot about half a block from my house. Was driving great, wasn't shifting early or anything. Got in the parking lot and came to a stop then tried to go. Nothing. Put it in N then back to D. Nothing. Reverse. Nothing. 1st/2nd. Nothing... Tried to put it in park. Horrible grinding noise. Put it in N and shut the engine off and then moved it to Park. Opened door and pushed the car and it rolls(with it in Park). So, it looks like the tranny is completely disengaged now... Was able to start it back up when it's in Park and it doesn't make any noise, but if I put it in gear and then try to put it in park, it makes a horrible grinding noise.

I had disconnected the wiring harness to the shift motor and forgot about it when I did my test drive. But even after I reconnected it and tried to put it in Drive, it still didn't make a difference. Hope that didn't goof things up.

This is just the strangest thing. We weren't having any issues at all with this until I tried to switch it into 4wd a few weeks ago... So, sound like a tranny rebuild/replacement? Not sure it'd be worth it on a 20 year old car...

Thanks!

 

[gmanpaint]

Your good. T-Case just slipped into Neutral is all. Get back under it, and move the selector until it stays put. Make sure the dash switch is in the 2wd (or whatever yours has for that), and try to get the shift motor back on.

That grinding noise was just the parking pawl. It couldn't go where it needed too, because the engine rpms was up, and was not allowing it. It will be fine once the case is back in gear.

If it doesn't want to go back on, it's not lined up right. Chock the wheels, Start the engine, foot on brake, trans in N, then turn the switch. Have somebody under the rig, and watching the backside of the shift motor to see if it turns. If it doesn't, try tapping on it with something solid, not real hard, but firm taps to try to free it up. Try the switch again.

If it moves back to 2wd, put it back on the case. Your good to go until you replace that shift motor.