Circuit Description

PCM controls fuel injector and starter operation based on vehicle theft deterrent password from the BCM. When ignition is first turned on, BCM sends a programmed password to the PCM. PCM acknowledges the password and responds to the BCM that normal fuel injector operation will continue. If PCM detects an incorrect password (Vehicle Theft Deterrent system failure or attempted vehicle theft), DTC P1631 will set. The engine will not start as long as the condition is present.

Conditions for setting DTC:

• PCM is detecting an incorrect vehicle theft deterrent password from Vehicle Theft Deterrent (VTD) system.
• VTD system allowed fuel delivery.
• Conditions present for greater than 2 seconds.