My elec. shift 4x4, power windows, interior lights, door and seatbelt buzzer, windshield wipers, and the solenoid that unlocks the column shifter when you press the brake all stopped working about a week ago, all at once. I know they all worked the day before I noticed this because i used all those features.

From what Ive read on here and other places on the internet I convinced myself it was the GEM module. I ordered a used one off ebay that is guaranteed to work but everything is the same after I changed it. There was absolutely no corrosion on an of the connectors on the GEM/fuseblock assembly.

I havent ruled out the possibility that I got a bad one from ebay, but while Im gettting a new one sent is there anything else I can check? Every fuse in the truck is good, in the cab and under the hood. Is it common for the GEM modules to go bad even is the windshield is not leaking and there isnt any corrosion? Is there any way to check the GEM with a multi-meter?

2001 F150, elec. shift 4x4, 5.4L

 

I read this and was like i swear i replied to that haha im green98 from the other place. Friendly bump to the top too.

 

yep, its me. I really need this fixed. the bad part is Im a service electrician. I can figure out just about anything AC. When it comes to troubleshooting on my truck there are so many modules and brains and everything is tied togther differently than Im used to... it just makes me feel kinda dumb.

 

Have you had the recall done on your truck yet ?
Recall 05S28 - for the leaky SCDS and the trucks going up in flames.

Did you check any fuses prior to replacing the GEM ?

It is possible that the GEM was bad, and you got another bad one, they are electronic devices. That said, there are a few common fuses with the problems your are seeing, in addition to the GEM controlling them.

elec. shift 4x4
Via CJB Fuse #15, via BPP, to GEM.
Power to transfer case relay via BJB Fuse #104.
Transfer case electric clutch via CJB fuse #23, via BJB Fuse #111. GEM controls the ground side of the coils for the transfer case relay, and the transfer case electric clutch.

power windows
via accy delay relay via BJB Fuse # 110 or BJB Breaker 601 if SCrew boy style. Gem only controls the OTD relay for the drivers side relay. Other windows are via the Accy delay relay direct ( controlled by GEM ).

interior lights
interior lamp relay via battery saver relay via CJB Fuse #14 for coils. Battery saver & interior lamp relays both controlled by the GEM ( on the ground side ). Interior lamp relay & battery saver relay both fed by BJB Fuse #103 ( for power to pin #30 of NO contacts ).

Warning Chime ( door and seat belt buzzer )
belt minder module CJB #29 & CJB #30 via BJB Fuse #111 and BJB #6. BJB #111 also feeds CJB Fuse #20, #21, #22 & 24. This is the ESOF & DTR PCM module, RCM, HVAC switch, and pass airbag module. GEM controls the signal input from the belt and key in ign, as well as the door ajar inputs.

windshield wipers
CJB Fuse # 11 via BJB Fuse # 113.
Also feeds CJB Fuse #5 for speed control servo, blend door fr HVAC, and function selector switch for HVAC

BPP switch (solenoid that unlocks the column shifter when you press the brake ) PCM controlled.
CJB Fuse #15 via BJB Fuse # 103 for GEM,
BPP switch is CJB Fuse # 13 via BJB Fuse # 103 . This is also the power to the speed control deactivation switch ( recalled switch ) and flasher relay.

PCM power relay
CJB # 2 via BJB #103
PCM power diode via CJB 30 via BJB Fuse #111
NO contacts of PCM Power relay feed BJB Fuses 23 & 18 both are via BJB Fuse #111

Have you added any thing to the truck ? ( fog lamps, amp, etc ).

 

Truck is all factory, it used to have an aftermarket stereo system in it, but the factory radio is back in it now... and it works. Other than that electronically stock I think.

I quickly tested all the fuses when this happened and they all tested good, but I will do it again tommorow. I had it at the ford dealer the morning this happened and while I was there I had them run the vin for recalls and the guy at the desk told me that nothing showed up, meaning that the recalls had been performed already or the vehicle was not affected by them.

The switch or sensor at the end of the brake fluid reservoir is leaking slightly. The wiring harness coming off of it has a tag that says it has a non repairable fuse inside and to replace the whole harness if it fails. The odd thing about it is that it has a standard blade fuse holder coming out of the loom with a 2 amp fuse in it. It was tripped and i replaced it the day before this all happened. I didnt think of that untill now, it didnt trip the fuse and the cruise control worked and then I pulled the fuse out of it just to be safe and then the next day this happened.

I really need 4x4 by this weekend, is there any way I can manually put it in
4x4?

 

ac controls work, i think the blend door is working, flashers work,

it says that there are no recalls for my vehicle on the ford website

 

How did you test all 58 fuses ?

If the connector at the end of the SCDS is leaking, there is a problem with it. It blew the fuse already, which means it has a problem. I would guess the recall was not done correctly. The dealer should have been able to tell you if the recall was done, and when / where. Your MY should have needed it, my '01 did.

The AC controls work, or the AC works ?

Does the blend door work, I think does not tell me much.

When you try to shift into 4Hi or 4Lo what happens ?

 

pulled the fuses out and tested them for continuity with my dmm.

the ac controls work as in i can change function, fans speed, and temp

i think the blend door works becuase it is involved in the the functions of the previous sentence, right?

when i turn the 4x4 switch no relays click like usual, no dash lights come on, and no 4x4 high or low

 

If you are sure the fuses are good, it sounds like a GEM problem with that list. The ESOF switch is directly connected to the GEM. If you don't even have a 2H indicator lamps illuminated, that is not a good sign.

 

I dont think Ive ever had a 2wd indicator, except for that position on the 4x4 switch. The lights above the 4x4 switch (2h, 4h, 4l) are lit up with the headlights on. Should I have one on the dash also?

also... if I had 2 bad gem modules in a row, is it possible that both these gem modules are malfunctioning the same way? it seems like eveyone has had a different set of symptoms but mine stayed the same with 2 different modules. It really makes me think that my issue is somewhere else because the symptoms remained constant and neither of my gem modules are corroded at all along with my fuse panel being good.

 

That should have been 4H in my post, or what is really the 4x4 indicator on the instrument panel.

This could be a problem with the range selector switch, if we remove the other things, and the GEM never sees the switch turn from one setting to the other.

If you had a 3.9K ohm, 1.1K ohm, and 360 ohm resistors, you could unplug the switch, and manually jumper the dark blue to dark blue wires on the range selector connector to test it.

One of the Dark blue wires ( the signal return ) is common from the range selector, and the windshield wipers, this is one thing that makes me think the GEM is no good ( or not installed correctly ).
This is also common to the head lamps on chime, door ajar condition, and fasten safety belt indicator.

Maybe check that you did not push pin 21 out of the connector on the GEM ?

If you remove this connector from the GEM, and it looks good, check the continuity from pin 21 to the 4WD range selector switch ( one of the 2 dark blue wires ) ?

This dark blue wire is pin 21 on the GEM connector, that is the gray 26 pin one. Pin 21 is on the 2nd row, opposite the locking tab. This connector is 2 rows of pins, 13 wide, off set in the center 8 are lower then the outside.

7 pins in the connector are unused.

 

pin 21 has continuity to the esof connector. pin 21 is fully inserted into the gem connector

 

where are you getting this info from. it would be nice to have a copy of the schematic. by the way i dont have any resistors lying around to test that switchany further

also... the gem i am trying to use does have the exact same markings as the one that came out, they were only manufactured about 1 month apart.

 

This is from the 2001 EVTM. I got mine from Helm Inc.

Item/Part #: FCS1226301 60.00 + S/H

www.helminc.com

The 2001's had a mid year change, the RAP was changed to a CSM, which look the same, have the same connector inputs on them, but are not interchangeable.
The build date change was 2-OCT-2000.

There is no note about the GEM, but this could have been after my paper EVTM was made.

 

I would say Bad GEM, the other way to confirm it is to buy a new selector switch, and try that ( without taking a trip to Radio shack to purchase some resistors ).