34 Part 1 of 2

Code 34 (Chart 1):

DERM Circuit Detail:

DESCRIPTION:

At "Turn-on" the DERM monitors the voltage at the Sense Low input (terminal A6) for 500 milliseconds. The DERM expects the voltage to be between 28% and 59% of "IGNITION 1" voltage before the 36VLR output is charged. If "IGNITION 1" circuit from the SIR fuse to the Dual Sensor is open or the "IGNITION 1" diode in the Arming Sensor is open the voltage at the Sense Low input (terminal A6) will be less than 4.6 volts and Code 34 will set.

TEST CONDITION:

Tested once during each ignition cycle at "Turn-on".

FAILURE CONDITIONS:

Code 34 will set if the voltage at the Sense Low input (terminal A6) is less than 28% of "IGNITION 1" output voltage for 500 milliseconds and 36VLR is less than "IGNITION 1" output voltage at "Turn-on".

NOTE: History code 34 will not set if a history code 51 is set.

CONDITIONS TO CLEAR:

To clear code 34, the ignition must be off long enough to assure the 36VLR supply voltage has fully discharged. A wait of ten minutes with the ignition "OFF" is usually sufficient to allow the 36VLR to discharge. Once 36VLR is discharged, the DERM will again check the failure conditions upon key on, If the failure conditions are not present (no failure indicated) then current code 34 will be cleared.

ACTION TAKEN:

DERM turns on the "INFLATABLE RESTRAINT" indicator lamp.

NOTES ON FAULT TREE:

1. Checks if fault is in Dual Sensor or CKT 1139.

2. Checks if fault is in Steering Column.

3. Determines if fault is in SIR Coil or Inflator Module.