In order for a theft deterrent vehicle to run, a password is communicated between the body function control (BFC) and the PCM. If a PCM is replaced, the new PCM needs to learn the correct password of the vehicle. When the new PCM is installed, the EEPROM calibration is flashed into the new PCM and the vehicle will learn the new password upon the initial ignition ON cycle. If the BFC is replaced, the PCM needs to learn the new password from the BFC. The Password Learn Procedure is as follows:

1. Attempt to the start vehicle. The vehicle will stall.
2. Leave the ignition ON until the Theft System telltale turns OFF (approx.10 minutes).
3. Turn OFF the ignition switch.
4. Attempt to the start vehicle. The vehicle will start on the this attempt. The password is now learned.

Attempting to start the vehicle by bypassing the theft deterrent system or substituting parts without performing the Password Learn Procedure may set a DTC P1631 and P1632.

If no password is received a DTC P1610, P1626 and P1632 may be set.

Refer to the applicable DTC table if set.