GM Service Manual Online
For 1990-2009 cars only

Circuit Description

The Calibration ROM check sum error detection is handled inside the control module. No external circuits are involved.

Conditions for Running the DTC

The microprocessor runs the program to detect a ROM check sum error after each power up. The only requirements are voltage and ground. This program runs even if the voltage is out of the valid operating range.

Action Taken When the DTC Sets

The microprocessor reverts to base operation values programmed for those blocks of data that have failed the ROM check sum test. The blocks of data that have not failed the check sum 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.

Diagnostic Aids

    • This DTC may be stored as a History DTC without affecting the operation of the module. If stored only as a History DTC and not retrieved as a current DTC, do not replace the module.
    • If this DTC is retrieved as a Current DTC, replace the module.

Step

Action

Yes

No

1

Did you perform the Diagnostic System Check for the system exhibiting the symptom?

Go to Step 2

Go to Control Module References for the applicable Diagnostic System Check

2

  1. Install a scan tool.
  2. Turn ON the ignition, with the engine OFF.
  3. Retrieve DTCs.

Is the DTC retrieved as a current DTC?

Go to Step 3

Go to Diagnostic Aids

3

Important: Perform the programming or setup procedure for the module if required.

Replace the control module setting the DTC as current. Refer to Control Module References .

Did you complete the replacement?

Go to Step 4

--

4

  1. Use the scan tool in order to clear the DTCs.
  2. Operate the vehicle within the Conditions for Running the DTC as specified in the supporting text.

Does the DTC reset?

Go to Step 2

System OK