Recently, the fob on my 98 refused to lock/unlock the doors. I re-synched it by holding the 2 buttons until the horn beeped, then it worked OK. Later that day, same problem, same solution. Thinking the battery was weak, I changed it, but no improvement.

I went & found the other fob, which I haven't used in several years, put in a new battery, and it has the same problem. My memory fails me, but I'm thinking I may have stopped using the old one because it had the problem I'm now seeing.

After searching this forum, it seems that there are a couple of possible causes: Poor solder connections in the fob(s), or the receiver module in the rear hatch area. My TPMS works OK, so can I rule out the receiver module? (If I understand correctly, the same module handles the TPMS and the fobs)

If it's a problem in the fobs, can anyone point me to a picture of the possible bad solder joints? Or make any other suggestions?

Thanks!

EDIT- I just went & looked at trouble codes in the DIC:

B2282H left door control module battery #1 fault
B2283H right door control module battery #1 fault
B2284H left door control module battery #2 fault
B2285H right door control module battery #2 fault
B2265H right vertical position sensor fault (mirror)
B0851H left seat control module battery 1 out of range
B0856H seat control module +5V reference signal out of range (not listed in my 98 service manual, but found it on the web for another year)

 

If TPMS is working then the receiver is not the problem.

Here is a good guide for the solder fix:

http://forums.corvetteforum.com/c5-t...em-solved.html

If that doesn't work and you want a GM FOB, Gene Culley has the best prices. I'd suggest you get the FOB for the 2000. It doesn't have the annoying passive feature but will work fine on all '97-00 cars. It runs about $60.00 which is cheaper than the '97-'99.

You can find cheaper non GM FOB's for as little as $25.00. I don't have any experience with them so I can't speak for their quality.

 

OK, after searching some more here & elsewhere, it became harder to ignore the apparently common solder joint problem, despite the codes I'm seeing relating to the door control modules.

First, I went back out, cleared the codes, then went through the fob training/synching. Same deal, they worked the first time or 2, then failed again. HOWEVER, there were no DIC codes set. I'm now thinking all those codes were set & leftover from when my battery went dead a couple of months ago.

I took my fobs apart, and BOTH have the failed solder tabs on the small rectangular component that's on an angle near the corner of the board.

I'm going to see if my shaky hands & aging eyesight can manage to re-solder these things & hope that solves the problem.

If I screw them up, I'll take your advice & buy a 2000 fob. I never use the passive mode anyway.

 

Just as a followup, (I feel like I'm talking to myself here ) re-soldering the 4 pins on both fobs seems to have fixed them. Both were quickly trained & synched to the car, and both still work after almost 24 hrs. Thanks for the link to the "fix" thread, Mark C5.


I had to file a pretty small tip on one of my soldering irons, but was able to get a small blob of solder on the end & touch it on each contact point for a second or so without burning up the circuit board.

Interesting to note that the failure points are directly under the "lock" button on the fob. Maybe too much thumb pressure on the button over time flexes the circuit board & causes the problem. I'll try to be more gentle in the future!


In the process or taking one of the fobs apart to clean it (before I read about the soldering fix) 2 of the button pieces tore off the rubber part in the fob. I'll try & bond them back in place with some silicone adhesive, or post in the parts wanted forum & see if anyone has a dead fob they would part with.