Supplemental Inflatable Restraint (SIR)

Code 31:

DERM Circuit Detail:

DESCRIPTION:

The voltage at the Sense Low input (terminal A6) is between 41% and 61% of 36VLR output voltage when 36VLR output of the DERM is functional. Should the circuit open between the 36VLR output and the Arming Sensor, "IGNITION 1" voltage will be supplying the deployment loop. The voltage at the Sense Low input (terminal A6) will decrease due to the decrease in the supply voltage and Code 31 will set after 700 milliseconds (if Code 42 is not set). Code 31 indicates an open in the wiring between the 36VLR output of the DERM and the Arming Sensor, an open diode in the Arming Sensor or a problem with Sense High or Sense Low circuits.

TEST CONDITION:

Tested every 100 milliseconds during "Continuous Monitoring".

FAILURE CONDITIONS:

Code 31 will set if:
1. The Voltage at the Sense Low input (terminal A6) is between 28% and 59% of Ignition 1 output voltage for 700 milliseconds.
2. Code 42 is not set.

CONDITIONS TO CLEAR:

Current Code 31 will clear if the voltage at the Sense Low input (terminal A6) is between 41% and 61% of 36VLR output voltage for 500 milliseconds.

ACTION TAKEN:

DERM turns on the "INFLATABLE RESTRAINT" indicator lamp.

NOTES ON FAULT TREE:

1. Checks if the fault is in the 36VLR circuit between the DERM and the dual sensor or if the fault is in the dual sensor.