R026

Diagnostic Chart:

Wiring Diagram:

CIRCUIT DESCRIPTION

When there is an open in the Driver's Inflator Module pigtail or the SIR Coil Assembly, the resistance between 'DRIVER'S SENSE HIGH', terminal 'B9', and 'DRIVER'S SENSE LOW', terminal 'B8' increases. This causes a larger voltage drop from the 'DRIVER'S SENSE HIGH' to the 'DRIVER'S SENSE LOW', across the 430 ohm resistor inside the DERM which connects these two terminals together. The increase in the voltage difference between 'DRIVER'S SENSE HIGH' and 'DRIVER'S SENSE LOW' is detected by the DERM during the 'Continuous Monitoring' tests and Code R026 is set indicating an open in the driver initiator circuit.

TEST CONDITION(S)

1. Tested every 100 milliseconds while 'Continuous Monitoring' tests active.

2. 'Initiator Circuit Resistance' tests are not active.

FAILURE CONDITION(S)

Voltage difference between 'DRIVER'S SENSE HIGH', terminal 'B9', and 'DRIVER'S SENSE LOW', terminal 'B8', is greater than or equal to a specified value for 500 milliseconds.

ACTION TAKEN

1. DERM turns on the 'INFLATABLE RESTRAINT' indicator.

2. 'SERVICE SUPPLEMENTAL INFLATABLE RESTRAINT' message is displayed on DIC.

NOTES ON FAULT TREE

1. Checks to make sure the steering column connector (C206) is connected, since Code R026 sets when the connector is apart.

2. Checks for proper terminal contact at the steering column connector. Refer to "INTERMITTENTS AND POOR CONNECTIONS" to properly check terminals. Intermittent Problems

3. Checks if fault is in the steering column. The SIR Load Tool J 38715 simulates the proper resistance of steering column wiring and components.

4. Determines if fault is in Driver's Inflator Module or in the SIR Coil. The SIR Load Tool J 38715 simulates the proper resistance of the Driver's Inflator Module.