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.

At this time, the SDM will establish communication with the passenger presence detection (PPD)/seat belt reminder (SBR) and the PPD/SBR will respond to the SDM by commanding the passenger air bag OFF indicator On for 5 seconds.

### 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 properly blink ON and OFF.

### Action Taken When the DTC Sets

The SDM commands the air bag indicator ON.

### Conditions for Clearing the DTC

Caution: The sensing and the diagnosis module (SDM) can maintain sufficient voltage to deploy the airbags and pretensioners for up to 1 minute after the ignition has been turned OFF and the fuse has been removed. If the airbags and pretensioners are not disconnected, do not begin service until one minute has been passed after disconnecting power to the SDM. Failure to do so may cause personal injury.

Caution: Do not strike or jolt the inflatable restraint sensing and diagnostic module (SDM). Before applying power to the SDM, make sure that it is securely fastened with the arrow facing toward the front of the vehicle. Failure to observe the correct installation procedure could cause SIR deployment, personal injury, or unnecessary SIR system repairs.

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
--- | --- | --- | --- | ---
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 | Go to Diagnostic System Check - Vehicle
2 | Inspect the fuse F11. Is fuse F11 blown? | -- | Go to Step 3 | Go to Step 4
3 | Replace the fuse F11. Did you complete the replacement? | -- | Go to Step 12 | --
4 |

1. Confirm that the ignition switch is ON.
2. Measure the voltage at terminal 5 of the passenger air bag/seat belt warning lamp connector.

Is the voltage as specified?

9-16 V

Go to Step 6

Go to Step 5

5 | Repair the wiring between fuse F11 and terminal 5 of the passenger air bag/seat belt warning lamp connector. Did you complete the repair? | -- | Go to Step 12 | --
6 | Inspect the connection between terminal 5 and terminal 6 (LHD), terminal 1 (RHD) of the passenger air bag/seat belt warning lamp. Is the connection OK? | -- | Go to Step 8 | Go to Step 7
7 | Replace the passenger air bag/seat belt warning lamp. Did you complete the replacement? | -- | Go to Step 12 | --
8 |

1. Confirm that the ignition switch is ON.
2. Disconnect the sensing and diagnostic module (SDM) connector.
3. Measure the resistance between terminal 6 (LHD), terminal 1 (RHD) of the passenger air bag/seat belt warning lamp and terminal 56 of the SDM connector.

Is the resistance as specified?

0 ohms

Go to Step 9

Go to Step 11

9 | Measure the resistance between the terminal 56 of the SDM connector and ground, battery positive. Are the resistances as specified? | ∞ | Go to Step 10 | Go to Step 11
10 | Replace the SDM. Did you complete the replacement? | -- | Go to Step 12 | --
11 | Repair the wiring between the terminal 56 of the SDM and the instrument passenger air bag/seat belt warning lamp. Did you complete the repair? | -- | Go to Step 12 | --
12 |

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