All of a sudden my FOB stopped working? I changed the battery, I tried to re-sycn and reprogam but nothing worked. Any suggestions would be greatly appreciated.

 

Possibly not the fob ? Not sure if it will throw a code, but there is a Comm section in the onboard diagnostics. Might want to pull the codes and see whats there.

If it turns out to be the fob, they are easily replaced. 2000 and older are a bit more expensive, but the 2001 - 4 you can get for less than $20 on the auction site, or an oem fob from Gene (supporting vendor, GM Parts House, link on left side of page).

 

 

Do you have a second fob? If so, try that one and see if it works. If not, could be the receiver in the car. Otherwise, the first fob may need replacement.

 

Is your TPS and A/C system working normally? If not check fuse 27 in the passenger side footwell fuse box. If that fuse is good pull your codes and post them here.

To enter the Diagnostic Display function perform the following steps in order:

1. Turn ON the ignition switch, engine OFF.
2. Press the RESET button to acknowledge any warning messages present.
3. Press the OPTIONS button on the Driver Information Center (DIC) and hold.
4. While holding the OPTIONS button press the FUEL button 4 times within a 10 second period.
5. System will first enter automatic display mode followed by the manual display mode.

The automatic display feature allow you to read each module DTC display function in an automatic display sequence. Each system module DTC will be displayed for 3 seconds followed by a 1 second pause before the next DTC is displayed in an automatic sequence. If no DTC information is sent to the IPC from the system currently displayed on the IPC, the IPC will display NO CODES for that system. At any time during the automatic display function, the manual display feature can be activated by pressing any button on the DIC except the E/M 5 button. The E/M 5 button is used to completely exit the DIAGNOSTICS mode at any time. If there is a communications problem between any system, the IPC will display NO COMM when the IPC is trying to communicate with that system. When all DTCs have been displayed for all systems, the IPC will display NO MORE CODES for 2 seconds then will enter the manual display mode, waiting for manual mode operation.

The manual display feature allows you to manually select each module DTC display function. The manual mode will automatically be entered after the automatic DTC display sequence is complete, or can be entered at any time during the automatic mode by pressing any button on the DIC except the E/M 5 (E/M 5 button is used to exit the DIAGNOSTIC mode at any time). When the manual mode is selected, the IPC will display the MANUAL DIAGNOSTICS mode message for 2 seconds, or until any button on the DIC except the E/M 5 is pressed. After the MANUAL DIAGNOSTICS mode message is displayed, the IPC will display the first system abbreviation and quantity of codes stored for that system, then the IPC will wait for further instructions. The buttons on the DIC provide the following functions when operating the on-board diagnostic feature in the manual mode:

DIC Button Function
FUEL 1 Previous DTC
GAGES 2 Next DTC
TRIP 3 Previous System
OPTIONS 4 Next System
E/M 5 Exit Diagnostics
RESET Clear DTCs

 

Following along what VJ said....try the second FOB if you have one.

AND, you may have to reset both FOBs at the same time. Not sure if this always happens but I bought a replacement one and to get it to work, I had to reprogram both as it became FOB #1 and my existing one became #2.

Weird but they both work now.

 

The system can store unique identity for two fobs as designed. The car new comes with two (flip the fob over, if oem it may have a big "!" or "2" formed into the plastic on the back of it ).

If ya loose one, and you know which one you still have, you can just make sure you order the other kind and it will store the memory settings according to the fob used.

No problem with using two #1 fobs or two #2 fobs, but obviuosly the system will only store one set of settings (seat distance etc .. .) and recall it when you hit whatever fob (position) its stored in.

 

Just curious.........Do you know what all fuse 27 controls? I pulled it yesterday for an AC problem, started to get warning messages when it was out for tire pressure monitor sytem and I think traction control as well, seemed like an unlikely alliance with the HVAC. After popping it back in all was well, no new codes but now my key fob didn't work (needed reprogrammed and now works fine).

 

The RF receiver for the fobs and the TPMS gets it's power from the A/C circuit.

Here is a partial schematic:

 

Take your fob apart and check the metal clip that retains the battery. The solder that attaches the clip to the circut board can crack and allow the clip to move, thereby causing a loss of power for the fob. If you can pull on the clip and it comes out of the circut board apply a little heat with a soldering iron and reattach the battery clip. Don't over do the heat, just enough to make the solder reflow. I think this solder failure come from dropping the key fob from time to time.

 

One of my FOBs stopped working. I popped it apart and found one of the components of the circuit board had freed itself and made a break for it. I just ordered a pair off ebay for $27.