Hey guys, I have a '97 F-150 Lariat... this truck has been just incredible. It's just about to roll over 250,000 miles and the only thing i've had to replace has been a condenser for the a/c.
That having been said, this truck has the twist ****, shift on the fly 4x4. Last night I was in my buddy's yard and I put the truck in 4hi just to pull into his grass and not damage it. Well I turn the **** back to 2hi and it disengages but the light stays on and it won't go back into 4wd. Another one of my friends who runs a transmission shop said to check the fuses first and then get back with him. I can't seem to find a fuse for this, and also, is it possible that it might be a "shift motor" or something like that...?

Help please! lol

Thanks!
Scott

 

I had a problem similiar to this. But mine was stuck in 4wd. Turns out my 4 wheel drive relay sensors got wet somehow and shorted out on me... might wanna look into it

 

Alrighty... Can you tell me where they're located?

I guess I really need to go buy a Chilton's manual don't I...

 

On my 06 they were near the top of the engine bay on the driver side. They are set high so they don't get wet but mine still did.

 

2003 f150 fx4 will not engage into 4hi or 4lo what could be the problem i checked the fuses already they were good. the light on dash comes on when i start it but that is it

 

I got the same issue on my 98 xlt, electronic on they fly feature, when I shift from 4hi to 2hi I don't get any clicking noise like you do when shifting to 4hi. Not sure if its suppose to make any clicking noise though, so I just assumed its back in 2hi because the front end doesn't rumble or rattle when turning like it does in 4wd but the 4x4 light stays on. I even tried stopping and putting in reverse, still the light stayed on. Only time the light turned off was when I turned off the engine and removed the key.

I read that it could be the vacuum solenoids or actuator(diaphragm), two solenoids located on the passenger side firewall near the fender and battery. The actuator is located on transfer case. I haven't tried messing with them yet but I not sure those would be causing the problem because 4hi engages and disengages. I guess I'll check all the vacuum lines for deterioration or leaks just to make sure.

Pictures and info on vacuum solenoid and diaphragm

Front hub actuator schematic

I hope its not the GEM that's causing the problem, if anyone solved this issue please let us know what you did.

 

Your truck's 4x4 system is controlled by the GEM. It receives input from the dash switch and then controls the t-case shift motor as well as the front axle vacuum motor. Most likely what has happened is that the contacts in the shift motor assembly, that tell the GEM what position the shift motor is in, got stuck in 4Hi. The GEM sees the 2Hi shift request and executes the shift. Because the contacts are dirty the GEM still sees the 4Hi position and keeps the 4Hi indicator light on. When you turn the **** back to 4Hi it thinks it is still in 4Hi and does not execute the shift. Your Mechanic friend should scan for GEM codes. BTY have you tried 4Lo?

.

 

JMC you might be onto something because after I turned the **** from 4hi to 2hi it goes back to 2wd, but with the 4x4 light still on I tried to flip the **** back to 4hi and got no clicking noise from the solenoids. The GEM must think its still in 4hi, would I be able to scan the GEM codes using an OBDII scanner or do you need a specific scanner from Ford? I haven't tried 4Lo, I'll give it a try and report back later. I guess I should also take a look at the shift motor contacts as well. I will let you know what I find.

 

The GEM codes you need to access are P1 codes (P1xxx). They are manufacturer specific so they mean different things for different brands. Check your scanner to see if it will read P1 codes.

Regards

Jean Marc Chartier

 

mine is stuck in 4lo and i have no 4x4 lights on i cant even get my 4x4 lights to come on i got it like this and havent figured it out i got it for 1500 bucks and its a 98 f150 ext cab 4.6 with 140,000 anyone have any ideas for mine?

 

I would guess that the shift motor on the transfer case is defective. That is the most common cause. Unfortunately that is only a guess. Without proper diagnostics it would be fool hardy to throw parts at it. I would suggest a new thread with all the particulars of your truck.

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I was finally able to get under the truck to take a look at the shift motor contact plate, if I'm correct it should be the grey round plate next to the shift motor with about 5 wires running to it, held on by 3 screws.



I was able to take the plate off, it has a half moon **** that protrudes out that goes into the gear on the transfer case shift motor. I assume that contacts with the little fingers that indication to the GEM what position you are in is located inside the grey plate I removed, but I can't figure out how to get into it without damaging the plate. I'm thinking there is some corrosion on the fingers or maybe the shift plate is misaligned some how that is giving the GEM an incorrect position. If you know how to get into it to to clean the fingers or maybe all i need to do is adjust the plate, but if you can offer some advise that would be great. Thanks.

 

i have a 2003 fx4 with the electronic shift control in the dash and it will not shift into 4hi or 4lo. had this problem before and it was a fuse problem but i checked that this time and thats not the case. also my light in the dash wont come on either. what could be the problem??

 

thats my new problem but i have gotten no help on it

 

yeah well for our sake... i have come to the conclusion that it might just be the switch in my dash and thats what my buddy who works in a ford dealership maitinence department thinks to so i ordered a new one today ill get back to you to see if that was the issue