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Home >> Chevrolet >> 2002 >> Blazer 4D Utility, 4WD, Part Time >> Repair and Diagnosis >> External Pages >> Different car >> Section 1693 (Theft Deterrent System - Immobilizer) >> Diagnostic Information and Procedures >> Diagnostic System Check - Theft Deterrent >> Test Description

Test Description

WARNING: This page is about a different car, the 2002 Oldsmobile Bravada, 2002 GMC Envoy XL, 2002 GMC Envoy, and 2002 Chevrolet TrailBlazer. However, it is still accessible from the selected car via links, so may be relevant.

The numbers below refer to the step number(s) on the diagnostic table.

  1. 2:  Lack of communication may be due to a partial malfunction of the class 2 serial data circuit or due to a total malfunction of the class 2 serial data circuit. The specified procedure will determine the particular condition.
  2. 3:  The symptoms list in Symptoms will determine the correct diagnostic procedure to use.
  3. 4:  The presence of DTCs which begin with "U" indicate some other module is not communicating. The specified procedure will compile all the available information before tests are performed.
  4. 5:  The presence of DTC P0601, P0602, P0603, P0604, P0605, P0606, P0607, P1600, P1621, P1627 or P1683 indicates an internal fault in the PCM.
  5. 6:  The presence of DTC B1000, B1004, B1007, or B1009 indicates an internal module fault.
  6. 7:  The presence of DTC P0562 or P0563 indicates a low or high battery voltage condition.
Diagnostic System Check - Theft Deterrent

Step Action Yes No
Schematic Reference: Theft Deterrent System Schematics 
1 Install a scan tool.
Does the scan tool power up?
Go to Step 2  Go to SCAN TOOL DOES NOT POWER UP in Data Link Communications
  1. Turn ON the ignition, with the engine OFF.
  2. Attempt to establish communication with the following modules:
    • Powertrain Control Module (PCM)
    • Theft Deterrent Control Module
    • Instrument Panel Cluster (IPC)
Does the scan tool communicate with all of the listed control modules?
Go to Step 3  Go to SCAN TOOL DOES NOT COMMUNICATE WITH CLASS 2 Device (W/O Immobilizer) in Data Link Communications
Select the display DTC function on the scan tool for the following modules:
  • Powertrain Control Module (PCM)
  • Theft Deterrent Control Module
  • Instrument Panel Cluster (IPC)

Does the scan tool display any DTCs?
Go to Step 4  Go to Symptoms - Theft Deterrent 
Does the scan tool display any DTCs which begin with a "U"? Go to SCAN TOOL DOES NOT COMMUNICATE WITH CLASS 2 Device (W/O Immobilizer) in Data Link Communications Go to Step 5 
Does the scan tool display DTC P0601, P0602, P0603, P0604, P0605, P0606, P0607, P1621, P1627 or P1683? Go to DIAGNOSTIC TROUBLE CODE (DTC) LIST Go to Step 6 
Does the scan tool display DTC B1000, B1004, B1007 or B1009? Go to DIAGNOSTIC TROUBLE CODE (DTC) LIST in Body Control System Go to Step 7 
Does the scan tool display DTC P0562 or P0563? Go to DIAGNOSTIC TROUBLE CODE (DTC) LIST Go to Diagnostic Trouble Code (DTC) List