Diagnostic Energy Reserve Module (DERM)

The Diagnostic Energy Reserve Module (DERM) maintains a 36-Volt Loop Reserve (36VLR) energy supply to provide deployment energy for approximately 10-14 minutes if voltage is low or lost in an accident. In addition, the DERM performs diagnostic monitoring of all system components, stores both current and past SIR system Diagnostic Trouble Codes (DTC) information, warns driver of SIR system faults by controlling INFLATABLE RESTRAINT indicator light, and records SIR system status during a vehicle accident.

The DERM is connected to the SIR harness by a 24-pin connector. The harness connector uses gold-plated terminals and a gold-plated shorting bar in the contact area. The DERM connector also has a gold-plated shorting bar to connect INFLATABLE RESTRAINT indicator input to ground when the DERM connector is disconnected. With the DERM disconnected, the INFLATABLE RESTRAINT indicator remains on when ignition switch is turned to RUN or START position. The DERM is located under the instrument panel.