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, the ignition and deployment loop voltages are measured to ensure that these voltages are within the normal 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.
The SDM tests the voltage continuously from the warning lamp terminal.
DTC Descriptor
This diagnostic procedure supports the following DTC:
DTC B2501 Passenger Air Bag Disabled Indicator Circuit Malfunction
Conditions for Running the DTC
Ignition voltage is within the normal operating voltage range.
Conditions for Setting the DTC
The passenger ON indicator lamp does not operate depending on the status of passenger presence.
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 | Value(s) | 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. 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 the fuse F3. Is fuse F3 blown? | -- | Go to Step 3 | Go to Step 4 |
3 | Replace the fuse F3. Did you complete the replacement? | -- | Go to Step 15 | -- |
4 |
Is the voltage within the indicated range? | 9-14 V | Go to Step 6 | Go to Step 5 |
5 | Repair the power supply and the wiring to the fuse F3. Did you complete the repair? | -- | Go to Step 15 | -- |
6 |
Is the bulb OK? | -- | Go to Step 8 | Go to Step 7 |
7 | Replace the bulb. Did you complete the replacement? | -- | Go to Step 15 | -- |
8 |
Is the voltage within the indicated range? | 9-14 V | Go to Step 10 | Go to Step 9 |
9 | Repair the wiring between the fuse F3 and the terminal 1 of the clock wiring connector. Did you complete the repair? | -- | Go to Step 15 | -- |
10 | Inspect the connection between terminal 1 and terminal 9 of the clock. Is the connection OK? | -- | Go to Step 12 | Go to Step 11 |
11 | Replace the clock assembly. Did you complete the replacement? | -- | 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 67 of the SDM and ground. Is the resistance as specified? | ∞ | Go to Step 14 | Go to Step 15 |
14 | Replace the SDM. Did you complete the replacement? | -- | Go to Step 16 | -- |
15 | Repair the wiring between the terminal 67 of the SDM and the clock. Did you complete the repair? | -- | Go to Step 16 | -- |
16 |
Does the DTC reset? | Go to Step 2 | System OK | |
