For 1990-2009 cars

### 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
--- | --- | --- | --- | ---
Warning: Refer to Sensing and Diagnostic Module Voltage after Ignition is Turned Off Warning in the Preface section. Warning: Refer to Sensing and Diagnostic Module Handling Warning in the Preface section. Schematic Reference: SIR Schematics Connector End View Reference: Component Connector End Views
1 | Did you perform the Diagnostic System Check - Vehicle? | -- | Go to Step 2 | Go to Diagnostic System Check - Vehicle
2 | Inspect the fuse F10. Is fuse F10 open? | -- | Go to Step 3 | Go to Step 4
3 | Replace the fuse F10. Did you complete the replacement? | -- | Go to Step 15 | --
4 |

1. Confirm that the ignition switch is ON.
2. Remove the clock assembly.
3. Measure the voltage from the fuse F10.

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 F10. Did you complete the repair? | -- | Go to Step 15 | --
6 |

1. Confirm that the ignition switch is OFF.
2. Inspect the bulb of the passenger air bag OFF indicator.

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 |

1. Confirm that the ignition switch is ON.
2. Measure the voltage from terminal 4 of the clock wiring connector.

Is the voltage within the indicated range?

11-14 V

Go to Step 10

Go to Step 9

9 | Repair the wiring between the fuse F10 and the terminal 4 of the clock wiring connector. Did you complete the repair? | -- | Go to Step 15 | --
10 | Inspect the connection between terminal 4 and terminal 1 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 |

1. Confirm that the ignition switch is OFF.
2. Disconnect the sensing and diagnostic module (SDM) connector.
3. Confirm that the ignition switch is ON.
4. Measure the voltage from terminal 56 of the SDM.

Is the voltage within the indicated range?

11-14 V

Go to Step 13

Go to Step 14

13 | Replace the SDM. Did you complete the replacement? | -- | Go to Step 15 | --
14 | Repair the wiring between the terminal 56 of the SDM and the instrument cluster. Did you complete the repair? | -- | Go to Step 15 | --
15 |

1. Reconnect all SIR system components.
2. Verify that all components, connectors, and connector position assurances (CPAs) are properly mounted.
3. Use the scan tool to clear the DTCs.
4. Operate the vehicle within the Conditions for Running the DTC as specified in the text.

Does the DTC reset?

--

Go to Step 2

System OK