R071

CIRCUIT DESCRIPTION
DTC RO71 and/or DTC RO75 is an indication of an internal DERM malfunction and will set if any of the following conditions are detected: 1) DERM energy reserve voltage discharge time failure for three consecutive ignition cycles ("Turn-ON" test), 2) DERM is unable to read from or write to EEPROM (tested during "EEPROM read/write cycle"), 3) Either "36 VLR" power supply voltage is above a specified value for 500 milliseconds ("Continuous Monitoring" test), 4) The DERM calculated number for the vehicle in which it is installed does not match the value stored in EEPROM.

DTC WILL SET WHEN
Any of the indicated malfunctions are detected by the DERM. Each of the failure conditions is tested at a different time: 1) At "Turn-ON," 2) Asynchronously, 3) During "Continuous Monitoring," 4) At "Turn-ON."

ACTION TAKEN
DERM turns "ON" the "AIR BAG" warning lamp and sets a diagnostic trouble code.

DTC WILL CLEAR WHEN
The indicated malfunctions are not detected by the DERM.