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Home >> Cadillac >> 2004 >> Escalade EXT >> Repair and Diagnosis (Single Page) >> Accessories & Equipment >> Anti-Theft Systems >> Theft Deterrent System >> Diagnostic Information and Procedures >> DTC B2957: Security System Sensor Data Circuit Low >> Test Description
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Test Description

The numbers below refer to the step numbers on the diagnostic table.

  1. 3:  Tests for proper operation of the circuit in the high voltage range.
  2. 4:  Tests for a short to ground in the Passlock™ sensor signal circuit.
DTC B2957

Step Action Value(s) Yes No
Schematic Reference: Theft Deterrent System Schematics 
Connector End View Reference: Theft Deterrent System Connector End Views 
1 Did you perform the Theft Deterrent (VTD) Diagnostic System Check? - Go to Step 2  Go to Diagnostic System Check - Theft Deterrent 
2
  1. Install a scan tool.
  2. Momentarily rotate the ignition switch to CRANK. Do not start the vehicle.
  3. Release the ignition switch to ON.
  4. With a scan tool, observe the Passlock data voltage in the Body Control Module Security Data list.
Does the scan tool indicate that the Passlock™ data voltage is within the specified range?		 0.4-4.9 V Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems Go to Step 3 
3 
  1. Turn OFF the ignition.
  2. Disconnect the Passlock ™ sensor connector.
  3. Turn ON the ignition, with the engine OFF.
  4. With a scan tool, observe the Passlock™ data voltage in the Body Control Module Security Data list.
Does the scan tool indicate that the Passlock™ data voltage is greater than the specified value?		 4.9 V Go to Step 7  Go to Step 4 
4  Test the Passlock™ sensor signal circuit for a short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.
Did you find and correct the condition?		 - Go to Step 10  Go to Step 5 
5 Inspect for poor connections at the BCM. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.
Did you find and correct the condition?		 - Go to Step 10  Go to Step 6 
6
IMPORTANT: When replacing the BCM, refer to Body Control Module (BCM) Programming/RPO Configuration in Body Control System.
Replace the body control module. Refer to Body Control Module Replacement in Body Control System.Did you complete the replacement?		 - Go to Step 10  -
7 Inspect for poor connections at the Passlock™ sensor. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.
Did you find and correct the condition?		 - Go to Step 10  Go to Step 8 
8 Replace the Passlock™ sensor in the electronic column lock module assembly. Refer to Ignition Lock Cylinder Replacement in Steering Wheel and Column.
Did you complete the replacement?		 - Go to Step 9  -
9 Perform the Programming Theft Deterrent System Components  procedure.
Is the repair complete?		 - Go to Step 10  -
10
  1. Use the scan tool in order to clear the DTCs.
  2. Turn OFF the ignition.
  3. Turn ON the ignition, with the engine OFF.
  4. Select the body control module display DTCs function on the scan tool.
Does the DTC reset?		 - Go to Step 3  System OK
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