GEM Location: Illegal, Trick Question?

[smooz]

Folks,

I started a thread asking for the location of the GEM on my '02:

http://www.explorerforum.com/forums/showthread.php?t=337111

I got some help but, when I looked as directed, I still couldn't find it. Turns out that the GEM doesn't exist on a vehicle built after 03/2002!!

First clue was looking at the warning light wiring diagrams on pages 12-39 and 12-40 in the Chilton manual. Then, I confirmed it with a local mechanic by him checking in Alldatapro.

The only thing we couldn't find is: What controls those functions that the GEM controls in earlier models?

Anyone have any ideas?

 

[EXPLORER04]

Are you able to pull any codes and are there any blown fuses. I had a similar issue of when turning the key the car did nothing. It was a blown ignition fuse under the hood.

 

[smooz]

Can't pull any codes. Handheld says it cannot communicate with computer or something like that. Pulled every fuse and checked continuty with a multi-meter. Also checked the diodes.
The local mechanic wants me to check the PCM relay.

 

[streetessencems]

Can't pull any codes. Handheld says it cannot communicate with computer or something like that. Pulled every fuse and checked continuty with a multi-meter. Also checked the diodes.
The local mechanic wants me to check the PCM relay.

The Body Control Module or Body security module replaces the GEM. It controls most of the same items but not all. Its located behind the right rear quarter panel. The Pcm relay is in the fuse box under the hood as is the ignition relay and accessory delay relay.
Check all relays, swap them around if they are the same.
Apparently there are fusible links from alternator to fuse box. doubt they are bad but check them. If your fuses, relays and modules all check out, i would check the underside of the fuse boxes for any melted/shorted wires.

 

[smooz]

I agree, That is what we found in All data also. But...we dug in a little deeper.

On Alldata, we looked up the circuits (Pin diagram) that the Security Module handles. They include door locks, door ajar switches, lights, horn, keypad, alarm, anti-theft switch, and such. In other words, all the stuff you would expect a "Security Module" to control.

It does not include voltage (all times), voltage (key in), voltage in run or accessory, wipers, washers, interior lamp, seatbelt indicator, seatbelt buckle switch, UDP diagnostics, Vehicle Speed Sensor, and oodles of multifunction switches just to name a few that Alldata shows on the Pin diagram that the GEM Module used to contol.

What controls all these functions since there is no more GEM?

 

[rrgone]

When I bought my 2002 Explorer I picked up the 2002 Ford Wiring Manual off Ebay. I soon realized that I had a "late build" Explorer and ended up getting the 2003 wiring manual to have on hand. That's what you want to look at.

The Instrument Cluster picked up most of the control functions you mentioned. The window wiper system has microprocessors built into the motor housings.

 

[EXPLORER04]

i was looking through my factory service manual and it looks like all the things that you mentioned can be traced back to the "central junction box" There must be a short somewhere in the supply line. Possibly when replacing the trans, something was pulled or damaged.