GEM?

Tiny
PROBLEMAUTO
  • MEMBER
  • 1998 FORD RANGER
  • 6 CYL
  • 4WD
  • AUTOMATIC
  • 98,000 MILES
My 4x4 quit working this winter, I checked the motor it is ok. My 4-hi, 4lo light keeps flashing and making a noise behind my radio. I pulled the radio out and there is what they call a GEM there. It has 4x4 sticker on it. Could this be my problem with my 4x4. Also my temp. Control does not work either. Could both of these be the possibility of a bad module. I would appreciate your input on this problem. Thank you problem auto.
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Monday, March 22nd, 2010 AT 7:13 PM

14 Replies

Tiny
RACEFAN966
  • EXPERT
If the shift motor is good the GEM is the next posible candidate. If you have a digital multi meter I can walk you through a few tests to determine this before replacing it. Let me know what you want to do.
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Tuesday, March 23rd, 2010 AT 10:02 AM
Tiny
PROBLEMAUTO
  • MEMBER
To racefan 966; yes I have a multi meter so testing it first would really help. Would this module have any effect on my heater control? Thank you problemauto
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Tuesday, March 23rd, 2010 AT 6:41 PM
Tiny
RACEFAN966
  • EXPERT
OK before getting to far do you have the means to scan the truck? What I need to know is if there is any codes stored in the GEM that may help point us to where we should start? Let me know and we will go from there.
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Wednesday, March 24th, 2010 AT 10:12 AM
Tiny
PROBLEMAUTO
  • MEMBER
Yes there is a code showing up on my scanner and it is p1781. I put a new 4x4 switch when this problem first showed up. Will this help you to diagnose the problem. Let me know if yopu need anything else. Problemauto.
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Thursday, March 25th, 2010 AT 4:18 PM
Tiny
RACEFAN966
  • EXPERT
Ok this is pointing to the PCM as the problem. Before changing it I need you to inspect the wiring from the gem to the switch and check for any breaks or ? Unplug the gem and check for corrosion. If that all looks good then use the pic below and unplug the gem and the switch and check the resistance at term 14.

Gem plug


http://www.2carpros.com/forum/automotive_pictures/249564_Graphic_208.jpg


Switch


http://www.2carpros.com/forum/automotive_pictures/249564_Graphic1_34.jpg

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Friday, March 26th, 2010 AT 10:07 AM
Tiny
COPPER12
  • MEMBER
  • 1998 FORD RANGER
  • 64,800 MILES
I replaced the GEM to coreect the inop 4wd problem. Now I have a speedo that is out of control. When going approx. 9 miles an hour, the speedo, and data on scanner, reads in the hundreds. I was told by dealer that no flashing would be required for gem. Is there some calibration step I'm missing. Thanks for your time.
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Tuesday, June 9th, 2020 AT 11:25 AM (Merged)
Tiny
RACEFAN966
  • EXPERT
The gem don't need to be flashed. Now it could be that the sensor on the top of the rear diff may have went bad that is what tells the cruise unit that then tells the cluster the speed. If you have a digital multi meter there is a test we can do to see if that is bad.
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Tuesday, June 9th, 2020 AT 11:25 AM (Merged)
Tiny
TTOCS
  • MEMBER
  • 1997 FORD RANGER
  • 6 CYL
  • 2WD
  • MANUAL
  • 120,000 MILES
I have a 97 ranger that I am the original owner of. Over the past few years I have started to have intermitten problems with my dome light staying on. I could not seem to figure out if it was related to the drivers side or passenger side door trigger nor if it had to do with weather. I figured out when it did this that I could temporarily remove a relay in the passenger side kick panel to turn it off and for some reason if I left it out for a day or so then it would be good for another month or so.

Now a month ago I started having problems with it staying on more constantly and I just got use to having the relay out and not having a dome light. For the last two weeks if I let the truck sit more then a day the battery dies on me. Today I hooked up an amp meter and started pulling fuses and isolated it to fuse #25, the GEM system fuse(with relay #1 still removed). When I pulled this fuse I could hear another relay in the dash(next to the radio) click. With the fuse in place and relay #1 still removed my current draw would go from.5A to 0 when I pulled this relay. I had a few extra relays and tried them but nothing worked.
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Tuesday, June 9th, 2020 AT 11:25 AM (Merged)
Tiny
DALE_COOK@ATT.NET
  • MEMBER
Bro, my 1996 2.3L Ranger Splash II, started blowing the starter-relay fuse and the brake-lamps. So I bought a multimeter decided to get busy.
First I remover my negative battery cable and hooked up a small test light between the free neg-cable and the neg-post of my battery. Yea! It glow. So I knew that I had a constant short.
Next I started pulling the main power fuses from under the hood and the glow quit when I pulled the Big Parking Lamp 20 Amp.
Then I went to the cab and started pulling, First I removed the Brakes; Starter Relay fuses, together. Now, even though that I had left these 2 fuses out, the bulb was still glowing. Then I started noticing this clicking noise, and kept pulling fuses until #25 quit making the clicking noise and the "Glowing test bulb, Die."
Common sense, says either the GEM-relay or its circuit is Shorting Out, or tied to something that is shorting out! Either way it is a drain Hope this helps, ya.
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Tuesday, June 9th, 2020 AT 11:25 AM (Merged)
Tiny
SALEMWW
  • MEMBER
  • FORD RANGER
I have a 1995 Ford Ranger that looks a little rough but still runs well enough for my oldest boy to cut his teeth on. The only thing ever needed is a starter replacement about 2 years ago and a clutch replacement that took place a few months ago. At any rate, it's a manual transmission, 140000 miles, 4 cylinder that began to exhibit a rapid parasitic battery drain (before the clutch repair so it's not related to that). I checked all the extras that I had installed, phone system, lighting etc thinking that I had some wiring shorting. But now I've found that pulling fuse #25 labeled "Speedometer/GEM system" drops the battery draw (Engine off) from 234 ma to about 4. The high draw on that circuit remains constant even after a couple of hours, leading me to think that the electronics/computer are never shutting down. The ignition switch has been loose for a whie and now is very loose. I wonder if there is an issue in the switch that is "fooling" the system into not shutting down. Other than the "GEM" system however, all other systems act as they should when the switch is off.

Any suggestions? I'm trying to get this thing ready for drivers ed.

Thanks.
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Tuesday, June 9th, 2020 AT 11:25 AM (Merged)
Tiny
JASON123
  • MEMBER
There is either a short in the speedometer wire or the hazards
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Tuesday, June 9th, 2020 AT 11:25 AM (Merged)
Tiny
FIXITMR
  • MEMBER
Did ya fix it? What was it?
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Tuesday, June 9th, 2020 AT 11:25 AM (Merged)
Tiny
JASON123
  • MEMBER
  • 1995 FORD RANGER
  • 150,000 MILES
I pulled the fuse there is a short there somewhere in the lines
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Tuesday, June 9th, 2020 AT 11:26 AM (Merged)
Tiny
KEN
  • ADMIN
Hello,

The GEM (generic electronic module) is basically a body control module. It controls things like interior lights, power windows, etc. It is located in the center of the dash here are some GEM wiring diagrams so you can see what it attracted and its location as well (below)

Check out the diagrams (Below)

Please let us know if you need anything else to get the problem fixed.

Cheers, Ken
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Tuesday, June 9th, 2020 AT 11:26 AM (Merged)

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