Anti-Theft System Diagnostic System Check

2002 Chevrolet Impala LSSECTION Anti-Theft System Diagnostic System Check
NOTE: Use this check as starting point for any anti-theft system complaint.
  1. Turn ignition switch to OFF position. Connect scan tool to Data Link Connector (DLC). Turn ignition switch to RUN position. If scan tool powers up, go to next step. If scan tool does not power up, go to TEST D: SCAN TOOL DOES NOT POWER UP  under SYSTEM TESTS.
  2. Turn ignition switch to RUN position. Connect scan tool to Data Link Connector (DLC). Using scan tool, attempt to establish communication with Body Control Module (BCM) and Powertrain Control Module (PCM). If scan tool communicates with BCM and PCM, go to next step. If scan tool does not communicate with BCM and PCM, see TEST C: SCAN TOOL DOES NOT COMMUNICATE WITH CLASS 2 DEVICE  under SYSTEM TESTS.
  3. Using scan tool, retrieve DTCs. If BCM and PCM DTCs are present, go to next step. If scan tool does not display any DTCs, perform appropriate symptom test. See SYSTEM TESTS in appropriate ANTI-THEFT SYSTEM article.
  4. Using scan tool, retrieve DTCs. If DTCs U1000-U1305 are not present, go to next step. If DTCs U1000-U1305 are present, go to TEST C: SCAN TOOL DOES NOT COMMUNICATE WITH CLASS 2 DEVICE  under SYSTEM TESTS.
  5. Using scan tool, retrieve DTCs. If DTCs P0601 or P0602 is present, see appropriate BODY CONTROL MODULES article. If DTCs P0601 and P0602 are not present, go to next step.
  6. Check for DTCs B1000, B1007 or B1009. If DTCs B1000, B1007 or B1009 is present, see appropriate BODY CONTROL MODULES article. If DTCs B1000, B1007 and B1009 are not present, go to next step.
  7. Check for DTCs B1327 or B1328. If DTCs B1327 or B1328 is present, see appropriate BODY CONTROL MODULES article. If DTCs B1327 and B1328 are not present, see DIAGNOSTIC TROUBLE CODE DEFINITIONS . Repair as necessary.
RENDER: 1.0x

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When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

  • You smell fuel, burning insulation, or see smoke.
  • Brakes feel soft, pull hard to one side, or make grinding noises.
  • The engine overheats, stalls repeatedly, or misfires under load.
  • You are missing required tools, torque specs, or safe lifting equipment.
  • You are not confident in the next step or safety outcome.