R053

Diagnostic Chart:

Wiring Diagram:

CIRCUIT DESCRIPTION

During the 'Initiator Circuit Resistance' tests, the DERM injects a 150 milliampere current from the 'DRIVER'S SENSE HIGH', terminal '139', to the 'PASSENGER'S SENSE LOW', terminal '137', for 50 milliseconds. The DERM then injects a 150 milliampere current from the 'PASSENGER'S SENSE HIGH', terminal 'A7', to the 'DRIVER'S SENSE LOW', terminal '138', for 50 milliseconds. During these tests, the DERM calculates the voltage difference between the 'DRIVER'S SENSE HIGH', terminal '139', and the 'DRIVER'S SENSE LOW', '138' terminals. This voltage difference is used to determine the combined resistance of the Driver's Inflator Module, SIR Coil, harness wiring and connector terminal contracts. Code R053 sets when resistance is greater than a specified value, or an open exits in the 'DRIVER'S SENSE LOW' circuit between the DERM and the steering column connector.

TEST CONDITION(S)

Tested once each ignition cycle during 'Initiator Circuit Resistance' tests 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 at DERM;

4. Ignition 1 voltage is greater than 7.25 volts at DERM.

FAILURE CONDITION(S)

Code R053 sets when the combined resistance (determined by the voltage difference between 'DRIVER'S SENSE HIGH' and 'DRIVER'S SENSE LOW') of the Driver's Inflator Module, SIR coil harness wiring and connector terminal contacts is greater than a specified value.

ACTION TAKEN

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

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

3. Code R053 remains set for the entire ignition cycle.

4. Current Code R053 clears each time the ignition switch is cycled from 'ON' to 'OFF'.

NOTES ON FAULT TREE

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

2. Checks for an open in the 'DRIVER'S SENSE LOW' circuit between the DERM and the steering column connector.

3. Checks for proper terminal contact at the DERM and the Steering column connectors. Refer to "INTERMITTENTS AND POOR CONNECTIONS" to properly check terminals. Intermittent Problems

4. Checks to make sure that an improperly mated connector did not cause the code to set.

5. 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 a Driver's Inflator Module.