Wireless entry problem
New User
Joined: Sep 2013
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FOBs
It is possible that the fobs you have are not correct for your vehicle. Since they were in bags, they did not come with the truck which makes them that much more suspect. You might do some Internet searching to find out what the part number is for stock fobs for your truck and compare that against what the fobs you have show for a part number.
-Rod
-Rod
I am the second owner of the truck. I suspect this truck went to 2LCustoms new to be built and in there installing a A/M security system either have unhooked or cut something that I haven't found or either caused damage to the factory GEM. Im just not sure exactly how to decide which is the problem.
Hotshot
Joined: Jan 2011
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From: Puget Sound
With possible "interference" by a vendor tinkering with your wiring, I'm in the tall weeds. I can find the original wiring, but there is no way for me to anticipate what's been boogered from afar.
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Joined: Sep 2013
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Now Im assuming there is no one item that can be unplugged that just controls the door locks. All of the plugs on the GEM control several functions. All of the other functions are working fine and none of those wires are unplugged and it don't have the water damage problem that I have read about. If there is no other single piece that can been unplugged and removed that controls just the door locks that I don't know about and it is controlled only by the GEM then I believe that I have a damaged GEM. Im going to do a little more research (including take it apart and look at it) and if I don't find anything else I will order me a new one. I don't mind replacing it; I just hate to do that and it still not be the problem. Thanks Paul
Logistics Pro
Joined: Jun 2009
Posts: 4,823
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From: Cedar Rapids, IA
To determine if there is a wiring issue between the GEM and the door locks, you could backprobe a few connections at the GEM to see if that activates the power locks or not. If that activates the locks, then you know the wiring between the GEM and the locks are good and the issue is either with the GEM or the programming of the fobs.
There are really only 3 wires from the GEM that are needed for the locks. If you backprobe these, one at a time to ground, you should get the described function. If you're unable to backprobe due to space constraints, then you could also unplug the GEM and use a grounded test light to trigger the signals right at the connector. Pin 13 (Pink/Yellow) at the GEM should activate all doors to lock. Pin 14 (Pink/Light Green) should unlock all doors. Pin 21 (Pink/Light Blue) should unlock only the driver's door.
Another thing you could do is find someone with a professional scan tool, then access the RKE system with the scan tool, check for diagnostic codes, and attempt to activate the locks via the scan tool. If that works, that pretty much tells you your GEM is working well enough to activate the locks as well.
-Rod
There are really only 3 wires from the GEM that are needed for the locks. If you backprobe these, one at a time to ground, you should get the described function. If you're unable to backprobe due to space constraints, then you could also unplug the GEM and use a grounded test light to trigger the signals right at the connector. Pin 13 (Pink/Yellow) at the GEM should activate all doors to lock. Pin 14 (Pink/Light Green) should unlock all doors. Pin 21 (Pink/Light Blue) should unlock only the driver's door.
Another thing you could do is find someone with a professional scan tool, then access the RKE system with the scan tool, check for diagnostic codes, and attempt to activate the locks via the scan tool. If that works, that pretty much tells you your GEM is working well enough to activate the locks as well.
-Rod
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FOBS
Thanks a lot. That's the info I was looking for on which wires did what. I didn't realize that a scan tool would have anything to do with the lock functions. I do have a friend at a shop with a scan tool. I will check that first. Is it possible that a program in the GEM that could have been lost and it could just be reprogramed?
If we find nothing I will have to drop the GEM down to access it but I will do that soon and unplug the wires and ground each and see the results.
Keep in mind that when you turn the key switch from off to on 5 times all of the locks activate as they should to be ready to program the clickers. Shouldn't that confirm that the wires from the GEM to the locks are in good shape. Assuming that function from the key switch to the locks is controlled by the GEM.
One last question: exactly what picks up the signal from the FOB clicker. Is there a wire somewhere for a antenna(like a garage door remote) or is there just something in the GEM receiving the signal. Thanks Paul
If we find nothing I will have to drop the GEM down to access it but I will do that soon and unplug the wires and ground each and see the results.
Keep in mind that when you turn the key switch from off to on 5 times all of the locks activate as they should to be ready to program the clickers. Shouldn't that confirm that the wires from the GEM to the locks are in good shape. Assuming that function from the key switch to the locks is controlled by the GEM.
One last question: exactly what picks up the signal from the FOB clicker. Is there a wire somewhere for a antenna(like a garage door remote) or is there just something in the GEM receiving the signal. Thanks Paul
Logistics Pro
Joined: Jun 2009
Posts: 4,823
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From: Cedar Rapids, IA
It could be possible for a Single Event Upset to have targeted only the portion of memory that addresses the FOB programming, but such an event would be very rare and I cannot say I've ever heard of such a thing happening to a GEM.
I haven't had a GEM apart yet to know if there is an antenna in one of the harnesses, but I suspect the antenna is internal to the GEM.
Accessing the GEM for diagnostic codes may be worthwhile. Per the factory service manual, one of the parameters monitored by the GEM during normal operation is, "GEM/CTM continuous self-test (RAM, ROM, EEPROM, A/D checking)".
There is a section in the factory service manual on how to troubleshoot a symptom of the FOBs not working to lock or unlock the doors. If you're interested in the PDF of the section, send me a Private Message with an e-mail address for you.
-Rod
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Joined: Sep 2013
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Fobs
Alright now; about the 4th paragraph you are getting over my head. LOL I have a friend with a shop that is a little less electronically challenged than I am. I sent you my email address.
The GEM is a fairly easy access in this truck so I think I will drop it and take a look and check the wires as you said and see if I see signs of a antenna wire clipped. (Just to satisfy my mind). If I dont see a problem Ill take it up to his shop with your info and we will take a look. Thanks a lot. Paul
The GEM is a fairly easy access in this truck so I think I will drop it and take a look and check the wires as you said and see if I see signs of a antenna wire clipped. (Just to satisfy my mind). If I dont see a problem Ill take it up to his shop with your info and we will take a look. Thanks a lot. Paul
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