DTC B1009: EEPROM Checksum Error: Description

Module calibrations are stored in the EEPROM. When ignition switch is first turned to ON position, module performs internal tests on the EEPROM and can determine integrity of its non-volatile memory.

Module compares its previously stored checksum with checksum calculated when ignition switch is first turned to ON position. If 2 checksums do not match, module will indicate a calibration malfunction (checksum error), setting DTC.

Conditions for setting DTC:

• Stored checksum does not match calculated checksum.
• Module detects an internal memory malfunction.
• Conditions must occur when ignition switch is first turned to ON position.