B2948

DTC B2948

CIRCUIT DESCRIPTION
The vehicle theft deterrent control module checks the theft deterrent exciter module supply circuit for a constant voltage condition.

CONDITIONS FOR RUNNING THE DTC
The theft deterrent control module must see the ignition switch input. The theft deterrent control module can not have DTC B1327 set as a current DTC.

CONDITIONS FOR SETTING THE DTC
The theft deterrent control module requires 1 second to monitor the ignition key. After the first second, the theft deterrent control module turns off the power to the theft deterrent exciter module. If the theft deterrent control module senses the supply to the theft deterrent exciter module is 12 V for 1 second, the theft deterrent control module sets this DTC.

ACTION TAKEN WHEN THE DTC SETS

IMPORTANT: If the theft deterrent control module is unable to measure the ignition key transponder value for 30 consecutive seconds, after the vehicle has started, the theft deterrent control module will enter a fail enable state. The vehicle will not stall or stop running. If the theft deterrent control module is in a fail enable state when the ignition is turned to OFF, it will remain fail enabled until the next time the vehicle is started. If the theft deterrent control module is fail enabled, the VTD system is NOT active and the vehicle will start. The theft deterrent control module WILL send its enable password even if a transponder value is not received. The theft deterrent control module will remain fail enabled until the module measures a valid key transponder value.

- The theft deterrent control module sends a class 2 message containing a disable password to the powertrain control module (PCM).
- The vehicle will not start.
- The theft deterrent control module sends a class 2 message to the instrument cluster to illuminate the SECURITY indicator on steady.

CONDITIONS FOR CLEARING THE MIL/DTC
The theft deterrent control module clears the current status of the DTC when it does not sense a 12 V condition on the theft deterrent exciter module supply circuit. The DTC will still be retrieved as current until the ignition switch is cycled. The DTC will become a history DTC at that time.

DIAGNOSTIC AIDS
Refer to Testing for Intermittent and Poor Connections and Testing for Electrical Intermittents in Diagnostic Aids.

TEST DESCRIPTION

Steps 1-4:

Steps 5-8:

The numbers below refer to the step numbers on the diagnostic table.
1. Be sure that the original ignition key issued with the vehicle is used when performing the Vehicle Theft Deterrent Diagnostic System Check.
2. Make sure the good ground used is separate from the grounds used by the vehicle theft deterrent module. Voltage measurement must not interfere with possible isolated module ground.