The following diagnostic chart must be used when all circuitry outside the sensing and diagnostic module (SDM) has been found to operate properly, as indicated by following the appropriate diagnostic trouble code (DTC) chart. The chart verifies the need for SDM replacement.
Circuit Description
When the SDM recognizes ignition voltage greater than 9 volts at terminal A1 of the SDM, the air bag indicator flashes 7 times to verify operation. At this time the SDM performs turn-on tests followed by resistance measurement tests and continuous monitoring tests.
When a malfunction is detected, the SDM sets a current DTC and illuminates the air bag indicator.
When the malfunction is no longer detected and/or the ignition switch is cycled, the SDM will clear current DTCs and move them to a history file, except for the DTC 051, 053, and sometimes 071. DTC 051 and 053 will not be cleared by the scan tool because these codes require replacement of the SDM. The SDM must be replaced only after the malfunction that set the DTC has been repaired.
Step | Action | Yes | No |
|---|---|---|---|
|
Caution: Refer to Sensing and Diagnostic Module Voltage after Ignition is Turned Off Caution in the Preface section. Caution: Refer to Sensing and Diagnostic Module Handling Caution in the Preface section. | |||
1 |
Does the indicator lamp flashes 7 times? | Go to Step 2 | |
2 |
Is the same DTC displayed that occurred when the SIR Diagnostic System Check was previously performed? | Go to Step 3 | |
3 |
Does the indicator lamp flashes 7 times? | System OK | Go to Step 4 |
4 |
Is the repair complete? | -- | |
