Removing the GEM in a dedicated track car -

4.6L (1996-2004 Modular) Mustang Technical discussions on 1996-2004 4.6 Liter Modular Motors (2V and 4V) within.

Thread Tools Search this Thread
Old 08-02-2014, 02:03 PM   #1
Thread Starter
AIStang's Avatar
Join Date: Aug 2014
Location: CA
Posts: 2
Default Removing the GEM in a dedicated track car

I apologize for the double post. I posted this in the General discussion sub forum and reading the description I noticed that forum said for non technical.

New poster bobble.

Ok I am cleaning up the wiring in my American Iron 2000 Mustang.

The car has a 4,6 Modular motor in it with a bunch of mod and a stock wiring harness .

I have a factory wiring diagram reprint and have been cleaning up the mess of a harness the previous builder had under the dash bar.

The car has none ,I repeat none, of the below.

No Lights -- other than brake lights
Door locks
Window defoggers

Ok you get the idea.

Only the engine controls that the PCM controls, antilock brakes and brake lights need to work.

My question is do I need the GEM?

On the wiring diagrams I don"t see a connection to the PCM. I know the instrument cluster is linked to the PCM along with the PATS and the GEM is linked to both of those.

It appears I could just remove the GEM and as long as the PATS was disabled with a tune the PCM would still function properly.

Does anyone on here really know about the GEM and it's interaction with the PCM?

AIStang is offline   Reply With Quote
Old 08-02-2014, 03:20 PM   #2
5th Gear Member
Join Date: Jul 2012
Location: ohio
Posts: 3,513

As far as I know the GEM (Generic Electronic Module) controls multiple functions: wipers, window switches, convertible top, airbag power, datalink, etc. You may loose the ability to communicate via an OBDII connection. There should be a fuse in the power junction under hood that you can pull that kills the GEM an check for engine functionality. Fuse number 7 I believe, GEM/interior lights.
I don't think the relation ship between it and the PCM is important for starting and running , only for communication of the OBDII diagnostics.
dawson1112 is offline   Reply With Quote
Old 08-04-2014, 01:28 PM   #3
2nd Gear Member
Join Date: Oct 2011
Location: Missouri
Posts: 227

Few months ago I was chasing a battery drain which ended up being associated with the GEM. Thought I was screwed. Until I found someone else who had the same problem on another forrm and all they did was pull the black and white wire (IIRC, defintely could be remembering the wrong wire). They said they had been running it for years like that with no side effects. Something like its an auxiliary power? Sure enough worked for me.

ANYWAYS, I'm pretty sure when I pulled the fuse for the GEM I couldn't turn the engine over...
Hopefully you can prove my memory incorrect on that. But. I had drain associated with two circuits. The subwoofers and the GEM. Pulling one of those fuses did not allow me to start the car. Seeing how the subwoofer fuse is still sitting in my console...

Its very possible the wiring in my car could be jacked up though as it has a Viper alarm which I'm sure was installed by a "certified technician".
unitedwestang is offline   Reply With Quote

Related Topics
Thread Thread Starter Forum Replies Last Post
Ford Racing Handling pack on a 2015 GT - anybody have it? squishbang Suspension 8 11-02-2015 04:42 PM
Wilwood/tilton pedal retrofit on 2007 GT flash_xx S197 Handling Section 4 09-21-2015 02:25 PM
Groaning noise coming from rear when turning right 92 5.0stang 5.0L (1979-1995) Mustang 4 08-13-2015 07:46 AM
FORD FRENZY!!! Milan Dragway-September 12th Milan Dragway Members Rides and Car Show Section 0 08-12-2015 04:43 PM
Torque Bias explained... ccwebb GT S197 General Discussion 2 08-11-2015 07:47 PM

Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

Forum Jump

Featured Sponsors
Vendor Directory

All times are GMT -5. The time now is 02:57 AM.

We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to and affiliated sites.