GM Service Manual Online
For 1990-2009 cars only

Diagnostic Instructions

    • Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
    • Review Strategy Based Diagnosis for an overview of the diagnostic approach.
    •  Diagnostic Procedure Instructions provides an overview of each diagnostic category

DTC Descriptor

DTC B1243 00: CD-Player Load or Unload Performance

DTC B1248 00: CD Changer Load/Unload mechanism Performance

Circuit/System Description

When the ignition is turned ON, the radio performs a self test to verify if any critical malfunction exists within the system.

Conditions for Running the DTC

The CD player/changer recovers from loading/ejecting error.

Conditions for Setting the DTC

The CD player/changer experiences a loading/ejecting error.

Action Taken When the DTC Sets

The radio displays a "Mechanism Error" message temporarily.

Conditions for Clearing the DTC

    • The condition for setting the DTC is no longer present.
    • The history DTC will clear after 50 fault-free ignition cycles.

Reference Information

Schematic Reference

Radio/Navigation System Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

Radio/Audio System Description and Operation

Electrical Information Reference

    •  Circuit Testing
    •  Connector Repairs
    •  Testing for Intermittent Conditions and Poor Connections
    •  Wiring Repairs

Scan Tool Reference

Control Module References for scan tool information

Circuit/System Verification

  1. Ignition ON, with a scan tool clear all DTCs.
  2. Radio ON, play a known good CD. Eject and reinsert the CD several times and verify B1243 or B1248 does not reset.
  3. If the DTC resets, replace the radio.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Control Module References for radio replacement, setup, and programming