LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Chevrolet >> 2000 >> Astro Van Cargo, AWD >> Repair and Diagnosis >> External Pages >> Different car >> Section 16 (Body Control Modules) >> Self-Diagnostic System >> Horns System Diagnostic System Check
April 5, 2026: LEMON Manuals is launched! Read the announcement.

Horns System Diagnostic System Check

WARNING: This page is about a different car, the 2001 GMC Safari and 2001 Chevrolet Astro. However, it is still accessible from the selected car via links, so may be relevant.
NOTE: Presence of DTCs which begin with "U" indicate some other module on class 2 serial data line is not communicating.
  1. Connect scan tool to Data Link Connector (DLC). DLC is located under left side of instrument panel. If scan tool powers up, go to next step. If scan tool does not power up, go to TEST E: SCAN TOOL DOES NOT POWER UP  under SYSTEM TESTS.
  2. Turn ignition switch to RUN position. Using scan tool, attempt to communicate with Body Control Module (BCM). If scan tool communicates with BCM, go to next step. If scan tool does not communicate with BCM, go to TEST D: SCAN TOOL DOES NOT COMMUNICATE WITH CLASS 2 DEVICE  under SYSTEM TESTS.
  3. Using scan tool, select DISPLAY DTCS function. Retrieve and record any BCM DTCs and their status. If scan tool displays any DTCs, go to next step. If scan tool does not display any DTCs, repair horns system by symptom. See appropriate STEERING COLUMN SWITCHES article.
  4. If scan tool does display any DTCs which begin with a "U", go to TEST D: SCAN TOOL DOES NOT COMMUNICATE WITH CLASS 2 DEVICE  under SYSTEM TESTS.
  5. If scan tool does not display any DTC which begin with a "U", perform appropriate test see DIAGNOSTIC TROUBLE CODE DEFINITIONS  .
scientia non olet · About LEMON Manuals