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 in order 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 programed 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 MIL/DTC

The DTC clears when the microprocessor runs a successful check sum test of the ROM.

Diagnostic Aids

    • This DTC may be stored as a history DTC with out 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

Value(s)

Yes

No

1

Did you perform the Diagnostic System Check?

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Go to Step 2

Go to Control Module References

2

Replace the module. Refer to Control Module References .

Did you complete the replacement?

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System OK

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