Chart 2

Code 22 Part 2 Of 3:

SIR Wiring Diagram:

DESCRIPTION:

The DERM injects a current of 75 milliamps through the steering column from the "Force High" output, terminal A4, to the "Force Low" output, terminal A10. By monitoring the difference between the voltage at the "Sense High" input, terminal A7 and the "Sense Low" input, terminal A6, the DERM calculates the combined resistance of the inflator module, SIR coil, harness wiring CKTs 347 and 348 and connector terminal contact in the steering column.

TEST CONDITIONS:

Tested once each ignition cycle during the "Steering Column Resistance Test" if:
1. No faults are detected during "Turn ON".
2. No faults are detected during continuous monitoring for 1 second.
3. No crank signal present.
4. "Ignition 1" voltage is present.

FAILURE CONDITIONS:

Code 22 will set if the combined resistance of the inflator module, SIR coil, harness wiring and connector terminal contact in the steering column is less than a specified value. Code 22 will set if any of these conditions are present:
A. The steering column resistance is less than a specified value.
B. The 430 ohm resistor in the resistor module is shorted
C. The high side of the deployment loop is shorted to the low side of the deployment loop, i.e. SIR cod shorted.

ACTION TAKEN:

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

CONDITIONS TO CLEAR:

Current Code 22 will be cleared each time the ignition switch is turned "OFF".

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

4. This test determines whether the fault is in the SIR coil.

5. This test checks the integrity of the 430 ohm resistor and associated circuitry in the resistor module.

6. This test checks the integrity of the 49.9 ohm resistor, 100 ohm resistor and associated circuitry in the resistor module.

7. This test checks the integrity of the two 2490 ohm resistor and associated circuitry in the resistor module.