Chart 2

Diagnosis Chart:

Electrical Chart:

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
DTC 21 sets when the combined resistance of the Inflator Module, SIR Coil, Resistor Module, harness wiring and connector terminal contact in the steering column is greater than a specified value.

CONDITIONS TO CLEAR
Current DTC 21 clears each time Ignition Switch is turned "OFF" and the fault is corrected.

ACTION TAKEN
DERM turns on "INFLATABLE RESTRAINT" warning lamp.

DESCRIPTION
The DERM injects a 75 milliampere current through the steering column from the Force Hi output (terminal A4) to the Force Low input (terminal A10). The DERM monitors the voltage at the Sense Hi input (terminal A7) and the Sense Low input (terminal A6) and calculates the combined resistance of the Inflator Module, SIR Coil, Resistor Module harness wiring (circuits 347, 348 and 349) and connector terminal contact in the steering column. DTC 21 sets when the resistance is greater than a specified value or the 100 ohm resistors within the Resistor Module is shorted.

NOTES ON FAULT TREE
1. Checks for an open in circuits 347, 348, 349 or Dual Sensor.
2. Determines if open is in circuit 347.
3. Checks 100 ohm resistor in Resistor Module.