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 B2502 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 OFF indicator lamp does not turn ON when the ignition switch is turned ON. |
| • | The passenger OFF indicator lamp does not turn ON when the vehicle is running with no person on the passenger seat. |
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 F4. Is fuse F4 blown? | -- | Go to Step 3 | Go to Step 4 |
3 | Replace the fuse F4. Did you complete the replacement? | -- | Go to Step 13 | -- |
4 |
Is the voltage within the indicated range? | 11-14 V | Go to Step 6 | Go to Step 5 |
5 | Repair the power supply and the wiring to the fuse F4. Did you complete the repair? | -- | Go to Step 13 | -- |
6 |
Is the voltage within the indicated range? | 11-14 V | Go to Step 8 | Go to Step 7 |
7 | Repair the wiring between the fuse F4 and the terminal 17 of the clock or terminal 11 of the instrument panel cluster. Did you complete the repair? | -- | Go to Step 13 | -- |
8 |
Is the voltage within the indicated range? | 11-14 V | Go to Step 9 | Go to Step 10 |
9 | Replace the SDM. Did you complete the replacement? | -- | Go to Step 13 | -- |
10 | Test for a short to ground, short to voltage or an open/high resistance between terminal 56 of the SDM and the instrument cluster (if equipped without a tachometer) or the clock (if equipped with a tachometer). Was a repair to the circuit necessary? | -- | Go to Step 13 | Go to Step 11 |
11 | Test for a short to ground, short to voltage or an open high/resistance between terminal 27 of the SDM and terminal 7 of the clock (if equipped with a tachometer) or terminal 23 (if equipped without a tachometer). Was a repair to the circuit necessary? | -- | Go to Step 13 | Go to Step 12 |
12 | Replace the clock assembly (if equipped with a tachometer) or the instrument panel cluster (if equipped without a tachometer). Did you complete the replacement? | -- | Go to Step 13 | -- |
13 |
Does the DTC reset? | Go to Step 2 | System OK | |
