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 deployment loops.
If the warning lamp operates properly ON and OFF, the SDM measures the voltage continuously from the warning lamp terminal.
DTC Descriptor
This diagnostic procedure supports the following DTC:
DTC B2500 Inflatable Restraint System Indicator Circuit
Conditions for Running the DTC
Ignition voltage is within the normal operating voltage range.
Conditions for Setting the DTC
The warning lamp does not blink properly ON and OFF.
Action Taken When the DTC Sets
The SDM commands the AIR BAG indicator ON.
Conditions for Clearing the DTC
The condition responsible for setting the DTC no longer exists and the scan tool Clear DTCs function is used.
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 Sensing and Diagnostic Module Voltage after Ignition is Turned Off Caution in the Preface section. Schematic Reference: SIR Schematics Connector End View Reference: SIR Connector End Views | ||||
1 | Did you perform a Diagnostic System Check - Vehicle? | Go to Step 2 | ||
2 | Inspect fuse F4. Is the fuse blown? | -- | Go to Step 3 | Go to Step 4 |
3 | Replace fuse F4. Is the repair complete? | -- | Go to Step 15 | -- |
4 |
Is the voltage within the specified range? | 11-14 V | Go to Step 6 | Go to Step 5 |
5 | Repair the power supply and the wiring to fuse F4. Is the repair complete? | -- | Go to Step 15 | -- |
6 |
Is the bulb OK? | -- | Go to Step 8 | Go to Step 7 |
7 | Replace the bulb of the air bag warning lamp. Is the repair complete? | -- | Go to Step 15 | -- |
8 |
Is the voltage within the specified range? | 11-14 V | Go to Step 10 | Go to Step 9 |
9 | Repair the wiring between fuse F4 and terminal 17 of the clock wiring connector. Is the repair complete? | -- | Go to Step 15 | -- |
10 | Inspect the connection between terminal 17 and 7 of the clock. Is the connection OK? | -- | Go to Step 12 | Go to Step 11 |
11 | Replace the clock. Is the repair complete? | -- | Go to Step 15 | -- |
12 |
Is the voltage within the specified range? | 11-14 V | Go to Step 13 | Go to Step 14 |
13 | Replace the SDM. Refer to Inflatable Restraint Sensing and Diagnostic Module Replacement . Is the repair complete? | -- | Go to Step 15 | -- |
14 | Repair the wiring between terminal 27 of the SDM and the clock. Is the repair complete? | -- | Go to Step 15 | -- |
15 |
Does the DTC reset? | Go to Step 2 | System OK | |
