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.
Upon passing these tests, 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.
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 F3. Is the fuse blown? | -- | Go to Step 3 | Go to Step 4 |
3 | Replace fuse F3. Is the repair complete? | -- | Go to Step 15 | -- |
4 |
Is the voltage within the specified range? | 9-14 V | Go to Step 6 | Go to Step 5 |
5 | Repair the power supply and the wiring to fuse F3. 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? | 9-14 V | Go to Step 10 | Go to Step 9 |
9 | Repair the wiring between fuse F3 and terminal B15 of the cluster wiring connector. Is the repair complete? | -- | Go to Step 15 | -- |
10 | Inspect the connection between terminal B15 and B13 of the cluster. Is the connection OK? | -- | Go to Step 12 | Go to Step 11 |
11 | Replace the cluster. Is the repair complete? | -- | Go to Step 15 | -- |
12 |
Is the resistance as specified? | 0 ohms | Go to Step 13 | Go to Step 15 |
13 | Measure the resistance between terminal 27 of the SDM connector and ground. Is the resistance as specified? | ∞ | Go to Step 14 | Go to Step 15 |
14 | Replace the SDM. Refer to Inflatable Restraint Sensing and Diagnostic Module Replacement . Is the repair complete? | -- | Go to Step 16 | -- |
15 | Repair the wiring between terminal 27 of the SDM and the cluster. Is the repair complete? | -- | Go to Step 16 | -- |
16 |
Does the DTC reset? | Go to Step 2 | System OK | |
