Chart 1

Code 25 (Chart 1):

DERM Circuit Detail:

DESCRIPTION:

The DERM grounds the Force Low input (terminal A 1O) and then monitors the voltage at the Sense Low input (terminal A6). If the voltage is greater than 3 volts Code 25 will set. Code 25 is an indication of a short to system voltage in the steering column, Dual Sensor, or associated wiring. Additionally, this code can be set if the actual resistance of the 100 ohm resistor within the Resistor Module is too high or is open.

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.

FAILURE CONDITIONS:

Code 25 will set if the voltage at the Sense Low Input (terminal A6) is equal to "IGNITION 1" voltage (+/- 2 Volts) during the first Portion of the Steering Column Resistance Test.

CONDITIONS TO CLEAR:

Current Code 25 will be cleared each time the Ignition Switch is turned OFF.

ACTION TAKEN:

DERM turns on the "INFLATABLE RESTRAINT" indicator lamp.

NOTES ON FAULT TREE:

1. Checks if fault is in Steering Column.

2. Checks if fault is a short to voltage on high side of the Steering Column. If no short to voltage is detected, 36VLR voltage will be measured. 36VLR is not system voltage.

3. Checks if fault is in Coil Wire or Inflator Module.

4. Checks if fault is a short to voltage in wiring harness or Dual Sensor.