Supplemental Inflatable Restraint (SIR)

Code 34:

SIR Wiring Diagram:

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 the "Ignition 1" circuit from the splice to the dual sensor is open, the voltage at the "Sense Low" input, terminal A6, will be less than 28% of "Ignition 1" voltage and Code 34 will set.

TEST CONDITIONS:

Test 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" voltage for 500 milliseconds and 36VLR is less than "Ignition 1" output voltage at "Turn-ON".

ACTION TAKEN:

DERM turns "ON" the "INFL REST" warning lamp.

CONDITIONS TO CLEAR:

To clear Code 34, the ignition must be "OFF" long enough to assure the 36VLR supply voltage has fully discharged (10 minutes). Once the 36VLR is discharged, the DERM will again check the failure conditions upon ignition "ON". If the failure conditions are not present (no failure indicated) then, and only then, will current Code 34 be cleared.

TEST DESCRIPTION: Number(s) below refer to circled number(s) on the diagnostic chart.

1. This test checks whether "Ignition 1" voltage is available at the dual sensor harness connector.

2. This test checks if voltage is available at harness connector terminal C (CKT 347).

3. This test determines whether the fault causing voltage loss is attributed to the wiring harness or to the dual sensor.