working. I have 2 that don't work. so what is in these units that makes them stop??? any ideas?\\


Rod


ps, 98 vette

 

I worked in automotive electronics and fixed hundreds of fobs. Most of the time, it was broken solder joints. The fobs go from hot to cold all of the time. Outside in the cold to your pocket or heated car or in the summer to your air conditioned car or house. The expansion and contraction will bust those solder joints. You can get a soldering iron, take the circuit board out and lay it on something non conductive, use a pencil eraser to push soldered components and joints around while you press the button. Or you can put it under a good magnifying glass and look for cracks around the joints. Re-solder them and test it out.

 

which side of the circut board. battery side or button side. its had to see!!! is there supposed to be a rattle inside? when i shake it i hear a rattle!!!

 

cr2032 batteries....

 

mine stop working even after i try and relearn them they stop working after i drive it and now they don't even relearn.

 

You may have had a component come loose from the circuit board. Pop it apart over a clean area and check. Check the top side with a magnifier. Look for micro sized cracks or circles around the solder joints. Re-solder them if you see them. If you're in doubt about any solder joints, go ahead and re-solder them. Don't get any IC's or transistors too hot with the soldering iron. Resistors and capacitors are less prone to heat failure. Take a pencil eraser and clean the contact area on the side where the squiggly lines are as that's where the buttons that you press create a short across those lines to activate a function. Everything on these fobs is surface mounted. If you don't have a good magnifier, just re-solder everything except the IC on the board. Just don't keep your soldering iron in one place too long. You don't have to use solder. Just heat the junction between the surface mounts and the board.

 

Here's re-synchronization and programming instructions from GM.

Transmitter Programming/Synchronization
Each transmitter has a unique Vehicle Access Code (VAC) that changes every 5 seconds. If a transmitter or receiver is replace, each transmitter must be programmed to the vehicle's receiver. Entering a specific button sequence on the DIC, up to three transmitters can be programmed into the receiver. After programming the transmitters to the vehicle, the receiver will update this code every 5 seconds in order to match the code programmed in the transmitter.

The transmitter may not communicate or become out of synchronization with the receiver if any of the following situations occurs:

The transmitter battery is disconnected.
The vehicle battery is disconnected.
The transmitter and the vehicle are separated for 2 weeks or more.
The receiver is disconnected.
Perform the synchronizing procedure if the transmitter does not communicate or becomes out of synchronization with the receiver. If the transmitter and/or receiver are replaced, preform the following programming procedure:

Programming Transmitters
Turn the ignition to ON.
Turn the radio to OFF.
Press the RESET button in order to clear any IPC warning messages.
Press and release the OPTIONS button on the DIC to scroll through the display options until the IPC display is blank.
Press and hold the RESET button for 3 seconds.
Press the OPTIONS button until FOB TRAINING message is displayed.
Press the RESET button in order to begin the programming sequence. The message HOLD LK + UNLK 1ST FOB will be displayed.
Simultaneously press and hold the LOCK and UNLOCK buttons on the first transmitter for 15 seconds. The IPC will indicate when that transmitter is programmed and when to proceed to the next. Repeat this procedure for each additional transmitter or press the OPTIONS button to exit.
Programming Cancellation
The receiver will cancel the programming sequence if any of the following conditions occur:

The program mode is exited through the DIC.
The ignition is turned to OFF.
The three transmitters have been programmed.
The RFA system has been in the program mode for longer than 2 minutes and no transmitters have been learned.
If the program mode is cancelled with less than three codes stored, the receiver will only accept the codes just stored. If the program mode is cancelled before any code is stored, the codes still remain valid.

The receiver retains all current access codes in memory if either of the following conditions occur:

A programming sequence is interrupted.
The battery is disconnected.
Synchronizing Transmitters
Preform the following procedure if a transmitter cannot communicate or becomes out of synchronization with the receiver:

Move a programmed transmitter within range.
Press the LOCK and UNLOCK buttons on the transmitter simultaneously for 7 seconds.
The horn will chirp once when the transmitter is synchronized. Repeat this procedure for each additional transmitter if needed.

 

Great info, thanks man!!!!



Rod

 

 

I may be mistaken but I think the rattle has to do with the passive locking feature. I had same issue with remote I got with my 98. I could reprogram it and it'd work for a minute or two then stop working. I changed the battery but no luck. I gambled that it was just a bad fob and bought a new replacement. I bought a 2000 year fob which is compatible with previous years (not 2001 and up though) but it doesn't have the passive switch. Been working with no issues for about 7 months now.