GEM controller question

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Your member profile lists a '99 so I'm assuming that's the model year in question. The '99 information I have shows a Remote Keyless Entry Module located under the package shelf (accessed from the trunk). I don't know where it would be in a convertible. I don't have a '99 so cannot verify the location.

My '01 and '03 wiring manuals imply the remote receiver has been incorporated into the GEM for those model years.
 
GEM module update

I swapped out the GEM module today, and yes, the new GEM module would not work with my current keys. I guess I could buy new keys from Ford and reprogram them myself. My car is a 99 GT.

It was interesting that the new GEM didn't blow the #7 15 amp fuse immediately like my current GEM module does. So, it's obvious to me that the old GEM module has a short circuit in its circuit board.

If you ever want to swap out your GEM module here's a trick :

Position a long screwdriver over the top of the fuse box, and press gently to release the lock tab on the GEM module. The GEM module will then slide off the mounting bracket. It's impossible to get one's hand on the locking tab.
 
I was not aware that the GEM is a programmed device. There is nothing in the Ford service manual repair procedure about it needing special re-programming (other than the FOB TIC codes).

I know that the PCM and the cluster (PATS) is a programmed device. As such, a change out requires re-programming. This is noted in the Ford service manual.

The key FOB re-programming can be done by the owner. It does not need anything special other than a working key.

If you buy new keys from Ford, they will NOT work. For the home user, to re-program new keys requries two WORKING keys. With less than two working keys, a dealer or locksmith is needed (or disable PATS with a tuner).

From your post, I am confused about what works and what does not. I am assuming the new GEM does not blow fuses.

Live and learn.

>>>GEM programming procedures from Ford service manual.
Programming —Keyless Entry Remote Transmitter
NOTE: All keyless entry remote transmitters (15K601) must be programmed at the same time.

NOTE: All previous transmitter identification codes (TIC's) will be erased when programming mode is entered.

NOTE: To program (or reprogram) the keyless entry remote transmitters into the generic electronic module (GEM)(14B204), perform the following steps.

Turn the ignition from OFF to RUN eight times within 10 seconds, ending in RUN. If the GEM has successfully entered program mode, it will lock and unlock all the doors.

NOTE: The first TIC must be entered within 7.5 seconds of entering the program mode and additional TICs must be entered within 7.5 seconds of the first TIC. The programming mode is exited whenever the timing constraints are not met.

Press any button on a keyless entry remote transmitter, and the doors will lock and then unlock to confirm that each keyless entry remote transmitter has been programmed.

If the door locks do not respond for any keyless entry remote transmitter, wait for several seconds and press the button again.

Turn the ignition switch to the OFF position, or wait up to five minutes after step 1, to exit program mode. If a keyless entry remote transmitter has been programmed (or reprogrammed), the GEM will lock and unlock all the doors one last time.
 
Yes,I have reprogrammed the transmitter before without any problem using the procedure on page 60 of my 99 Mustang Owner's Guide.

Now, on page 61 they indicate you need two (2) previously programmed SecuriLock keys , if you want to program another key. But after running my test (detailed below) why bother ?

What's working on my car ? Everything but the courtesy lights (dome, trunk, etc). And Fuse #7 literally "pops" immediately.

When I put in the salvage yard GEM module, the fuse did not blow, yet the courtesy lights still didn't work. That's the mystery. The courtesy lights should have worked with the "new" GEM. And, if I had a short elsewhere in the harness, then the fuse would have blown again. Is that logical ?

Therefore, it seems that my original GEM module has a dead short on its circuit board. I followed every wire for the courtesy lights and could not find a short.

Thanks for the replies/help, though.

I'll tear into the salvage GEM and have a look at the circuitry.I probably will find a couple EPROMS and resistors, and cheap capacitors. I'll post back.
 
Maybe I am just slow tonight. I am still having trouble understand the resuls so far. Can you answer the following questions?

Are any fuses blowing now?

Does the car start with the ignition key?

Does the remote FOB work?

What happens when the remote reprogramming steps are performed?

Does the remote FOB work after the reprogramming steps have been performed?

Do the courtesy lights turn on via the dash light switch (rotated all the way CCW)?

What else does not work at this point.

IMO, there is a possibility that by actually performing the remote re-programming steps, the PCM will erase and re-set the GEM to work in its new home. Seams worth it to avoid a trip to the stealer ship.
 
Maybe I am just slow tonight. I am still having trouble understand the resuls so far. Can you answer the following questions?

Are any fuses blowing now?

Does the car start with the ignition key?

Does the remote FOB work?

What happens when the remote reprogramming steps are performed?

Does the remote FOB work after the reprogramming steps have been performed?

Do the courtesy lights turn on via the dash light switch (rotated all the way CCW)?

What else does not work at this point.

IMO, there is a possibility that by actually performing the remote re-programming steps, the PCM will erase and re-set the GEM to work in its new home. Seams worth it to avoid a trip to the stealer ship.

The old GEM has been re-installed, and so

1. Yes, the #7 fuse still pops immediately
2. Yes, the car starts with the ignition key (original key, original GEM)
3. Yes , the FOB works
4. Didn't have to reprogram the fob, since the original GEM was re-installed
5. I thought the remote transmitter and the key are two separate circuits ?
6. With new/different GEM did not try this as the trunk lid was open, driver's door was open,and neither bulb lit. But #7 fuse stayed in circuit.
7. At this point, the courtesy light circuit is FUBAR, and that's the only electrical problem right now. The keys, and the idiotic "one touch" power window feature (also a GEM thing) also work.

Sure looks like a circuit problem in the GEM to me, but what do I know ?
 
The purpose of the questions were to nail down the state of affairs with the new GEM. It is obvious that the old GEM has a problem.

I was wondering if the owner re-programming steps were performed with the new GEM, if this would reset/re-program the GEM for its new home.

It was unclear to me if the ignition key worked with the new GEM. If the key does not work, then going to the dealer for re-programming should be considered.

Good luck.