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 B1013: Calibration Read Only Memory (ROM) Checksum Error

Circuit Description

The electrically erasable programmable read-only memory (EEPROM) checksum error detection is handled inside the control module. No external circuits are involved.

Conditions for Running the DTC

The module runs the program to detect an EEPROM checksum error after each wake-up. The only requirements are battery positive voltage and ground. This program runs even if the voltage is out of the valid operating range.

Conditions for Setting the DTC

The module retains an inverse copy of the digital value stored in certain blocks of memory in the EEPROM. The module then reads the information from those certain blocks and adds the stored inverse value to the current value. If they do not equal 0, the module sets the DTC.

Action Taken When the DTC Sets

The module reverts to base operation values programed for those blocks of data that have failed the checksum test. The blocks of data that have not failed the checksum test are not affected.

Conditions for Clearing the DTC

    • A current DTC clears when the malfunction is no longer present.
    • A history DTC clears when the module ignition cycle counter reaches the reset threshold, without a repeat of the malfunction.

Circuit/System Verification

  1. With a scan tool, clear the DTC.
  2. If the DTC will not clear, replace the module that set the DTC.
  3. Ignition OFF, remove the scan tool, open and close the drivers door.
  4. Wait 60 seconds, then recheck for DTCs.
  5. If DTC B1013 returns, replace the module.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Control Module References for control module replacement, setup, and programming