For 1990-2009 cars

The following KEY STATUS messages may be shown on the scan tool after commanding FIRST KEY CODING and KEY ADD:

1. IGNITION OFF STATUS This message informs the technician that the ignition is OFF during the key coding process. Turn the ignition ON during key coding, but do not start the engine.
2. KEY IS OCCUPIED Only 5 keys may be coded. If a new key is desired, the previous key codes must be deleted. Up to 5 keys may then be authorized.
3. ALREADY AUTHORIZED Key coding is being attempted with a key that is already authorized.
4. ERROR NO. A3, A4, A5 There is no communication between the transponder in the ignition key and the detection coil. Follow the steps below to diagnose the problem:

• | Try a different key. If a different key works, the problem was in the original key.

• | If trying a different key resulted in the same error message, replace the detection coil.

5. INVALID KEY The communication between the immobilizer control unit and the key transponder has not validated the key. Follow the steps below to diagnose the problem:

• | Code the key. Refer to Programming Additional Keys .

• | If the same message is received after key coding, inspect the connection of the detection coil.

• | If the detection coil is okay, replace the immobilizer. Refer to Theft Deterrent Module Replacement .

6. NO TRANSPONDER DETECTED The fault may be in ignition key transponder, the detection coil, or the Immobilizer. Follow the steps below to diagnose the problem:

• | Try a different key. If a different key works, the problem was in the original key.

• | If trying a different key resulted in the same error message, inspect the connection of the detection coil.

• | If the connection of the detection coil is okay, disconnect the detection coil and use an ohmmeter to inspect for an open detection coil.

• | If the detection coil was not open, replace the immobilizer control unit. Refer to Theft Deterrent Module Replacement .