For 1990-2009 cars

### Diagnostic Instructions

• | Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.

• | Review Strategy Based Diagnosis for an overview of the diagnostic approach.

• | Diagnostic Procedure Instructions provides an overview of each diagnostic category.

### Diagnostic Fault Information

Circuit | Short to Ground | High Resistance | Open | Short to Voltage
--- | --- | --- | --- | ---
Voltage Reference | 1 | 1* | 1 | --
Passenger Air Bag OFF Indicator Control | 4 | 2* | 2 | --
Passenger Air Bag ON Indicator Control | 5 | 3* | 3 | --
1. No indicators will illuminate. 2. The OFF indicator will not illuminate. 3. The ON indicator will not illuminate. 4. The OFF indictor will illuminate any time the ignition is ON. 5. The ON indictor will illuminate any time the ignition is ON.

* High resistance may cause any or all indicators to illuminate less bright than normal.

### Circuit/System Description

The passenger air bag ON/OFF indicators are used to notify the driver when the passenger presence system has enabled or disabled the I/P inflator module. When the ignition is turned ON, the ignition voltage is supplied to the passenger air bag ON/OFF indicators and to the passenger presence system module. The sensing and diagnostic module (SDM) grounds all indicator control circuits to the passenger air bag ON/OFF indicators for illumination. The SDM receives serial data messages from the passenger presence system to illuminate the indicators as necessary.

### Reference Information

#### Schematic Reference

SIR Schematics

#### Connector End View Reference

Component Connector End Views

#### Description and Operation

SIR System Description and Operation

#### Electrical Information Reference

• | Circuit Testing

• | Connector Repairs

• | Testing for Intermittent Conditions and Poor Connections

• | Wiring Repairs

#### Scan Tool Reference

Control Module References for scan tool information

### Circuit/System Verification

Note: The passenger air bag ON and OFF indicators may not operate as expected if there are supplemental inflatable restraint (SIR) DTCs. Repair all SIR DTC before proceeding with this diagnostic.

1. Ignition ON, the passenger air bag ON and OFF indicators should both illuminate for approximately 5 seconds for a bulb check.
2. Monitor the parameter Passenger Presence Detection Occupancy Status with a scan tool. With the passenger seat unoccupied, the parameter should display Empty. The passenger air bag OFF indicator should illuminate.
3. Apply enough weight to change the parameter display to Occupied. The passenger air bag indicator should switch from OFF to ON within 5 seconds.

### Circuit/System Testing

Note: When removing connectors inspect for damage or corrosion. Damage or corrosion in the following requires repair or replacement of the affected.

• | Inflatable restraint passenger air bag on/off indicator.

• | Inflatable restraint passenger air bag on/off indicator wiring harness.

1. Ignition OFF, disconnect the harness connector at the S26 inflatable restraint passenger air bag ON/OFF indicator.
2. Ignition ON, verify a test lamp illuminates between the voltage reference circuit terminal 8 and ground.

⇒ | If the test lamp does not illuminate, test the voltage reference circuit for a short to ground or an open/high resistance. If the circuit tests normal test or replace the S26 inflatable restraint passenger air bag ON/OFF indicator.

3. Connect a test lamp between the ignition circuit terminal 8 and the control circuit terminal 2.
4. With the passenger seat unoccupied, then occupied the test lamp should switch states within 5 seconds.

⇒ | If the test lamp is always on, test the control circuit for a short to ground. If the circuit tests normal replace the K36 SDM.

⇒ | If the test lamp is always off, test the control circuit for a short to voltage or an open/high resistance. If the circuit tests normal replace the K36 SDM.

5. Connect a test lamp between the ignition circuit terminal 8 and the control circuit terminal 3.
6. With the passenger seat unoccupied, then occupied the test lamp should switch states within 5 seconds.

⇒ | If the test lamp is always on, test the control circuit for a short to ground. If the circuit tests normal replace the K36 SDM.

⇒ | If the test lamp is always off, test the control circuit for a short to voltage or an open/high resistance. If the circuit tests normal replace the K36 SDM.

7. If all circuits test normal, replace the S26 inflatable restraint passenger air bag ON/OFF indicator.

### Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

• | Hazard Warning Switch Replacement

• | SIR/SRS Wiring Repairs

• | Control Module References SDM replacement, setup, and programming