if you replace that module then you will have to do a relearn, the instructions must be followed correctly.
Passkey III – transponder ignition key. The Passkey III anti-theft system uses a
transponder inside the head of the ignition key. The exciter inside the ignition lock
cylinder energizes this transponder when the ignition switch is turned on. The
transponder transmits a unique signature to the theft deterrent control module. If the
key signature transmitted is acceptable to the theft deterrent control module the theft
deterrent control module will transmit fuel enable password to the PCM. If the fuel
enable password is correct the PCM will start the vehicle.
To perform a relearn on a 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.
1. Insert a master key (black head) into the ignition switch.
2. Turn key to the “ON ” position without starting the engine. The security light should
turn on and stay on.
3. Wait for 10 minutes or until the security light turns off.
4. Turn key to the “OFF ” position for 5 seconds.
5. Turn key to the “ON ” position without starting the engine. Security light should turn
on and stay on.
6. Wait for 10 minutes or until the security light turns off.
7. Turn key to the “OFF ” position for 5 seconds.
8. Turn key to the “ON ” position without starting the engine The security light should
turn on and stay on.
9. Wait for 10 minutes or until the security light turns off.
10. Turn key to the “OFF ” position. The key transponder information will be learned on
the next start cycle.
11. Start the vehicle. If the vehicle starts and runs normally, the relearn is complete.
12. If additional keys need to be relearned, turn the key to the “OFF ” position.
13. Insert the next key to be learned. Turn the key to the “ON ” position within 10
seconds of removing the previously used key.
14. 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.
15. Repeat steps 12 through 14 for any additional keys.