DTC B1658: EEPROM Checksum Error: Description

DTC applies to Heater and A/C Programmer Module (HCM), Memory Seat Module (MSM) if equipped, Pass-Key III® Vehicle Theft Deterrent Module (VTD) and Standard Body Module (SBM). Calibrations are stored in Electronically Erasable Programmable Read Only Memory (EEPROM). When ignition switch is first turned to RUN position, module performs internal tests on EEPROM and can determine integrity of its non-volatile memory. Module compares the new calculated checksum with the checksum it has previously stored.

DTC B1658 will set when ignition switch is first turned to RUN position, stored checksum does not match newly calculated checksum and affected module detects an internal memory malfunction (checksum error). No driver warning message will be displayed. DTC B1658 can be cleared using scan tool or on-board diagnostics, or history DTC will disappear after 50 consecutive ignition cycles if fault conditions do not reoccur.