Circuit Description
When the ignition switch is turned to ON, the sensing and diagnostic module (SDM) will perform a turn-on test to diagnose critical malfunctions within the SDM itself.
These test ignition and deployment loop voltages are measured to ensure that they are within their normal voltage ranges. The SDM monitors the voltages at the driver low and the passenger low to detect shorts to ground or voltage in the deploy loops.
If the warning lamp operates properly ON and OFF, the SDM measures the voltage continuously from the warning lamp terminal.
Conditions for Setting the DTC
The warning lamp does not blink properly ON and OFF.
Reference
When the ignition switch is turned ON, the warning lamp blinks 7 times during 7 seconds.
If the warning lamp stays ON or blinks a second after the above normal blinking, 7 times during 7 seconds, then it is regarded as a defect, old or current. Please inspect the defect with the scan tool.
Step | Action | Values | Yes | No |
|---|---|---|---|---|
|
Caution: Refer to Sensing and Diagnostic Module Handling Caution in the Preface section. Caution: Refer to SRS Sensing and Diagnostic Module Handling Caution in the Preface section. | ||||
1 | Inspect fuse F4. Is the fuse blown? | -- | Go to Step 2 | Go to Step 3 |
2 | Replace fuse F4. Is the repair complete? | -- | -- | |
3 |
Is the voltage within the specified range? | 11-14 V | Go to Step 5 | Go to Step 4 |
4 | Repair the power supply and the wiring to fuse F4. Is the repair complete? | -- | -- | |
5 |
Is the bulb OK? | -- | Go to Step 7 | Go to Step 6 |
6 | Replace the bulb of the air bag warning lamp. Is the repair complete? | -- | -- | |
7 |
Is the voltage within the specified range? | 11-14 V | Go to Step 9 | Go to Step 8 |
8 | Repair the wiring between fuse F4 and terminal B15 of the cluster wiring connector. Is the repair complete? | -- | -- | |
9 | Inspect the connection between terminal B15 and B7 of the cluster. Is the connection OK? | -- | Go to Step 11 | Go to Step 10 |
10 | Replace the instrument cluster. Refer to Instrument Cluster Replacement in Instrument Panel, Gages and Console. Is the repair complete? | -- | -- | |
11 |
Is the voltage within the specified range? | 11-14 V | Go to Step 12 | Go to Step 13 |
12 | Replace the SDM. Refer to Inflatable Restraint Sensing and Diagnostic Module Replacement . Is the repair complete? | -- | -- | |
13 | Repair the wiring between terminal 27 of the SDM and the instrument cluster. Is the repair complete? | -- | -- | |
