Scan Tool Diagnosis

Use the scan tool in order to monitor the communications between the BCM and the PCM/VCM. The scan tool also displays Passlock data. The Passlock data list display is located under the PASSLOCK selection. This list shows the status of the hardwired connections from the Passlock sensor to the BCM. These scan tool values may be very useful in diagnosing the Passlock system.

The Passlock system is designed in order to deter theft, even if various parts are changed. The following components may not be changed without the possibility of going into no-start condition:
^ The Passlock sensor
^ The Powertrain Control Module (PCM)
^ The Body Control Module (BCM)
^ The Vehicle Control Module (VCM)

If any of these parts are replaced, refer to the Learn Procedure in BCM Programming/RPO Configuration. The BCM and the PCM/VCM require the full 10 minutes in order to complete a lockout cycle. The ignition key MUST remain in the RUN position until the telltale turns to the OFF position. If the ignition key is turned from the RUN position before the telltale turns to the OFF position, you will have to repeat the lockout cycle. The Passlock system requires 3 consecutive lockout cycles in order to complete the 30 minute learn procedure for a changed component. Refer to Theft Deterrent Diagnostic System Check for more information on the Passlock system.