C5 FOB will not hold programming
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From: georgia
C5 FOB will not hold programming
Replaced the battery in my fob (1999), I reprogram it and the fob works for a few minutes and then loses the program. I reprogram and it works fine and then again stops working after a few minutes. Any ideas? Thanks If I discover a resolution I will post it.
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The resolution is to buy another fob. They wear out.
I had the same exact thing happen last week. So far his new fob hasn't skipped a beat. I spoke to him yesterday about something else.
I had the same exact thing happen last week. So far his new fob hasn't skipped a beat. I spoke to him yesterday about something else.
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From: georgia
Ok thanks, they are expensive, but if that is all then I will try that. Just didnt want to spend the dough and find out that wasnt the issue. Thanks!!
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The cold joints are a problem on the early fobs. I fixed the fob on my 99 using a harbor freight 10x loupe to identify the problem area, and harbor freight butane solder torch with fine tip to reflow.
Then I upgraded the fobs and TPMS together to the 01+ stuff. No more problems.
Then I upgraded the fobs and TPMS together to the 01+ stuff. No more problems.
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From: georgia
Issue is with both FOBs
Weird thing is that both of my FOBs are doing the exact same thing. I program them and after 10 minutes the lose the program. I am almost thinking that it may be something in the door module/control? Is that where the hardware is which receives and holds the program? Maybe I need to replace that?
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From: georgia
Not certain what you are doing that you are calling "programming the FOB" Programming the FOB is started by pressing the OPTIONS button on the dash until you get to a blank screen and then pressing and holding the RESET button for 2 seconds until the message FOB training is displayed. Re-syncing the FOB's is a different process that only works after the FOB's have been "trained" or programmed to the car. When you re-sync the FOB you press and hold the lock and unlock button at the same time. If the FOB being used has already been trained to the car and the FOB is transmitting correctly, the horn will honk. Re-syncing the FOB is a process that only works on the early year keyless entry system. If you try that with a FOB from a 2001 - 2004 keyless entry system NOTHING happens.
Door Control Module has nothing to do with the programming/training of the FOB's. The Remote Function Adapter and BCM work in conjunction to perform the programming of the FOB id's which is stored in the RFA. The programming function is basically the BCM via commands over the serial data buss instructing the RFA to store the FOB id information when it is transmitted by the FOB.
If you are re-syncing the FOBS and then the FOB works for a minute or so and then no longer works until you "re-sync" the FOB again, the RFA is NOT forgetting anything. It is the FOB that for what ever reason is no longer transmitting. So the problem is at the FOB and not somewhere else...........
Early year FOB's were crap. Quality control of the soldering of the tiny components onto the circuit board inside the plastic housing was basically NON EXISTENT. Because both FOB's exhibit the same issue is not reason to suspect that the problem lies with something else in the keyless entry system.
Both your FOB's have issues with the solder joints on the circuit board.
Door Control Module has nothing to do with the programming/training of the FOB's. The Remote Function Adapter and BCM work in conjunction to perform the programming of the FOB id's which is stored in the RFA. The programming function is basically the BCM via commands over the serial data buss instructing the RFA to store the FOB id information when it is transmitted by the FOB.
If you are re-syncing the FOBS and then the FOB works for a minute or so and then no longer works until you "re-sync" the FOB again, the RFA is NOT forgetting anything. It is the FOB that for what ever reason is no longer transmitting. So the problem is at the FOB and not somewhere else...........
Early year FOB's were crap. Quality control of the soldering of the tiny components onto the circuit board inside the plastic housing was basically NON EXISTENT. Because both FOB's exhibit the same issue is not reason to suspect that the problem lies with something else in the keyless entry system.
Both your FOB's have issues with the solder joints on the circuit board.
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Ok this forum has been so helpful and I really appreciate the information. I have been reprogramming as you describe and that is when they only function for a few minutes. When I try to re-sync both FOBs as you described. I never get the horn to honk so the re-syncing does not seem to be working. When I reprogram, both work flawlessly for 3-5 minutes. If I try to re-sync, absolutely nothing happens. So I guess I have to decide if I should purchase new FOBs at $120ea or start researching how to upgrade to the 2001 as someone else made a suggestion as I have the 1999.
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From: Round Rock Texas
Procedure to upgrade. Not all that expensive. Hard part is finding the rfa box. Also with that you got two choices zo6 will not have tpms function base model will. http://www.superchevy.com/how-to/vemp-1212-installing-late-c5-tpms-sensors-on-a-1997-2000-model/
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From: Round Rock Texas
Also if you can find the rfa module they listed let me know i found an alternative one and got it cheap. My total was. Rfa 50.00 tpms all four 25.00 key fobs 8.00
Ops fogot cable as add on part on amazon was $5.00
Ops fogot cable as add on part on amazon was $5.00
Last edited by sirdano; May 21, 2018 at 12:32 AM.
Melting Slicks
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From: Round Rock Texas
And i went through the same problem with my 98. I tired soldering and they worked for a little but started having problems again. Got bad were it would only unlock at door. Then would reprogram then 8 hours later would not work. Thats when i upgraded mine
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From: georgia
Thanks to everyone for all the advice! VERY HELPFUL. I just could not understand how both FOBs went out at the same time and kept thinking it had to be something else. I brought in one of the key FOBs today to a local PC repair shop. They charged me twenty bucks to re-solder the FOB based on the picture which was sent to me earlier in the post. It is now working!!!! Who knows how long it will last, but at least I know for sure now that it is the key FOB. I think I am still going to pursue upgrading with the parts just suggested because I do not feel like going through all this again ( and it sounds like i will). The little things in life that make my day!
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From: Troy Michigan
Put the FOB printed circuit board in the oven
Thanks to everyone for all the advice! VERY HELPFUL. I just could not understand how both FOBs went out at the same time and kept thinking it had to be something else. I brought in one of the key FOBs today to a local PC repair shop. They charged me twenty bucks to re-solder the FOB based on the picture which was sent to me earlier in the post. It is now working!!!! Who knows how long it will last, but at least I know for sure now that it is the key FOB. I think I am still going to pursue upgrading with the parts just suggested because I do not feel like going through all this again ( and it sounds like i will). The little things in life that make my day!
I had the same problem with my 99 FOB. I could sync the FOB but the next time I used it, it didn't work.
I read the posts on re-soldering several components and tried it but didn't have success.
I recently had a problem with an 8 year old LG 55" TV regarding the HDMI input solder joints failing. Online research resulted in a suggested fix for the HDMI mother board to put it in the oven, component side up, at 385 deg. F. for 8 minutes. It worked and I tried it on the circuit board of the FOB and it has been working perfectly for 3+ weeks.
