Circuit Description

EEPROM write error detection is internal. No external circuits are involved. For DTC to set, microprocessor must run program to detect a write error when ever it writes to EEPROM. Program runs even if the voltage is out of the valid operating range.

Microprocessor first writes information to a cell, or address in EEPROM. Microprocessor then reads information and compares to what was sent to the address. If they do not match after three consecutive attempts, microprocessor will set DTC B1007. When DTC is set, microprocessor finds another area to write information to. This new area becomes permanent area for storage of this information. DTC will clear when microprocessor makes a successful write to EEPROM.