B0091

DTC B0091

CIRCUIT DESCRIPTION
When the ignition is turned ON, the inflatable restraint sensing and diagnostic module (SDM) performs tests to diagnose critical malfunctions within the SIR system. The SDM monitors the instrument panel (I/P) module disable switch - signal and I/P module disable switch indicator - control circuits in order to determine whether or not to disable the inflatable restraint I/P module. The SDM also monitors the I/P module disable switch - signal and the I/P module disable switch indicator - control circuits for an open, high resistance, short to ground or short to voltage condition.

DTC DESCRIPTORS
This diagnostic procedure supports the following DTC:
DTC B0091 Active Switch Wrong State

CONDITIONS FOR RUNNING THE DTC
Ignition 1 voltage is within the normal operating voltage range.

CONDITIONS FOR SETTING THE DTC
- The PSIR switch must be in the OFF position.
- The voltage detected in the I/P module disable switch - signal circuit is less than 1 volt.
- The voltage detected in the I/P module disable switch indicator - control circuit is greater than 1 volt.

ACTION TAKEN WHEN THE DTC SETS
- The SDM defaults to the OFF position, disabling the I/P module.
- The SDM attempts to turn the inflatable restraint I/P module disable switch indicator ON and OFF every 5 seconds.
- The SDM commands the AIR BAG indicator ON via Class 2 serial data.

CONDITIONS FOR CLEARING THE DTC
- The condition responsible for setting the DTC no longer exists and the scan tool Clear DTCs function is used.
- A history DTC will clear once 255 malfunction free ignition cycles have occurred.

DIAGNOSTIC AIDS
Thoroughly inspect the wiring and the connectors. An incomplete inspection of the wiring and the connectors may result in misdiagnosis, causing a part replacement with the reappearance of the malfunction.

The following are possible causes of the malfunction:
- An open or a high resistance in the I/P module disable switch - signal circuit
- An open or a high resistance in the I/P module disable switch indicator - control circuit
- A short between the I/P module disable switch-signal and I/P module disable switch indicator - control circuits
- Damage or corrosion on the I/P module disable switch harness connector
- Damage or corrosion on the I/P module disable switch indicator harness connector
- Damage or corrosion on the SDM harness connector
- An internal I/P module disable switch malfunction
- An internal I/P module disable switch indicator malfunction
- An internal SDM malfunction

If an intermittent condition exists, refer to Diagnostic Aids for Circuit Testing and Wiring Repair procedures.

TEST DESCRIPTION

Steps 1 - 12:

Steps 13 - 15:

The numbers below refer to the step numbers on the diagnostic table:
6. This step tests to see if the I/P module disable switch indicator is damaged.
9. This step tests to see if there is an open or high resistance in the I/P module disable switch-signal circuit.
10. This step tests to see if there is an open or high resistance in the I/P module disable switch indicator-control circuit.
11. This step test to see if there is a short between the I/P module disable switch-signal and the I/P module disable switch indicator-control circuits.