DTC B1558: BCM EPROM Checksum Error: Description

Module calibrations are stored in the EPROM. When ignition is first turned on, module performs internal tests on EPROM to determine integrity of its non-volatile memory. Module compares its previously stored checksum with checksum calculated when ignition is first turned on. DTC B1558 will set when stored checksum does not match calculated checksum. When DTC B1558 is set, PZM uses default values for any memory function in EPROM that is corrupt.