Good luck with this. I’m really curious as to what the problem is.
Been following along, hope the new BCM does the trick--looking forward to the update. Good luck!
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Good luck with this. I’m really curious as to what the problem is.
ok, I did a little looking and apparently the onstar does have a backup battery (on some vehicles), however this battery is not contained in the bcm. it is either under the passenger seat or attached to the side of the onstar module, I looked under my seat and there isn't one there just the backup sensor module. on these trucks the onstar module is under the radio behind the dash, not sure if they have a backup battery the part is not listed anywhere only the module, only onstar batterys I can find are for impala, saturn.Gm even lists one of the features of the onstar button is to send help for a dead vehicle battery.
And if you have push start?just for reference in case this is the problem (30 min relearn)
GM Vehicle Theft Deterrent (VTD) Relearn Procedures
To perform a relearn for Passkey III system, make sure there is a fully charged battery in the vehicle. The battery will be used for 30 minutes without the alternator available for charging. Connect a battery charger to the battery to ensure power is available while programming. When performing this relearn, all previously learned keys will be erased. Additional keys may be relearned immediately after the first key has been learned by inserting the additional key and turning the ignition switch to on within 10 seconds of removing the previously learned key.
- Insert a master key (black head) into the ignition switch.
- Turn key to the “ON” position without starting the engine. Security light should turn on and stay on.
- Wait for 10 minutes or until the security light turns off.
- Turn key to the “OFF” position for 5 seconds.
- Turn key to the “ON” position without starting the engine. Security light should turn on and stay on.
- Wait for 10 minutes or until the security light turns off.
- Turn key to the “OFF” position for 5 seconds.
- Turn key to the “ON” position without starting the engine. Security light should turn on and stay on.
- Wait for 10 minutes or until the security light turns off.
- Turn key to the “OFF” position. The key transponder information will be learned on the next start cycle.
- Start the vehicle. If the vehicle starts and runs normally, the relearn is complete. If additional keys need to be relearned:
- Turn the key to the “OFF” position.
- Insert the next key to be learned. Turn the key to the “ON” position within 10 seconds of removing the previously used key.
- Wait for security light to turn off. It should happen fairly quickly. You may not notice the lamp, as the transponder value will be learned immediately
- Repeat steps 12 through 14 for any additional keys.