Diagnostic Energy Reserve Module (DERM)

Notice: Do not open the DERM case for any reason. Touching the connector pins, or the soldered components may cause electrostatic discharge damage. Replacement is the only way to repair a malfunctioning DERM.

The DERM performs the following functions in the Supplemental Restraint System (SRS):
^ Energy Reserve: The DERM maintains a 36 Volt Loop Reserve (36 VLR) energy supply in order to provide deployment energy when the voltage is low or lost in a frontal crash.
^ Malfunction Detection: The DERM performs diagnostic monitoring of the Supplemental Restraint System (SRS) electrical components.
^ Malfunction Recording: The DERM provides SRS diagnostic trouble code information through a scan tool.
^ Driver Notification: The DERM controls the AIR BAG warning lamp. This warns the vehicle driver of SRS malfunctions.
^ Frontal Crash Recording: The DERM records the SRS status during a frontal crash.

The DERM is connected to the SRS wiring harness by a 24-way connector. When the DERM harness connector is disconnected, a shorting bar connects the AIR BAG warning lamp to ground . This causes the AIR BAG warning lamp to light up whenever the ignition switch is at the RUN or the START position.