Circuit Description
WARNING: This page is about a different car, the 2004 Chevrolet Corvette. However, it is still accessible from the selected car via links, so may be relevant.
The control module calibrations are stored in the EEPROM when the ignition switch is turned OFF. When the ignition is first turned ON, the control module performs internal tests on the EEPROM to determine the integrity of this non-volatile memory. The control module compares its previously stored checksum with the checksum calculated when the ignition is first turned ON. If the two checksums do not match, the control module will indicate a calibration malfunction (checksum error) is current and set this DTC.