Air Bag Indicator Circuit Malfunction (Passenger)
Air Bag Indicator Circuit Malfunction (Passenger)
Diagnostic Instructions
* Perform the Diagnostic System Check - Vehicle Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis Strategy Based Diagnosis for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions Diagnostic Procedure Instructions provides an overview of each diagnostic category.
Diagnostic Fault Information
Circuit/System Description (C99)
When the ignition switch is turned to ON, the inflatable restraint sensing and diagnostic module (SDM) continuously checks the air bag enable/disable switch position switch and circuit defect by letting regular voltage flow through the switch circuit and verifying the current. The passenger air bag switch controls when the air bag is enabled or disabled and notifies the driver when the passenger instrument panel air bag is enabled or disabled using the passenger air bag ON/OFF indicators. When the SDM receives the signal from the passenger air bag disable switch (on/off), the SDM will then provide voltage to the appropriate indicator.
Circuit/System Description (ALO)
The passenger air bag ON/OFF indicators are used to notify the driver when the passenger presence system has enabled or disabled the passenger instrument panel air bag. When the ignition is turned ON, the ignition voltage is supplied to the passenger presence module. When the SDM receives the appropriate serial data message from the passenger presence system the SDM will then provide voltage to the appropriate indicator.
Reference Information
Schematic Reference
SIR Schematics [1][2]Air Bag Systems
Connector End View Reference
Component Connector End Views Connector End Views By Name
Description and Operation
SIR System Description and Operation SIR System
Electrical Information Reference
* Circuit Testing Circuit Testing
* Connector Repairs Connector Repairs
* Testing for Intermittent Conditions and Poor Connections Testing for Intermittent Conditions and Poor Connections
* Wiring Repairs Wiring Repairs
Scan Tool Reference
Control Module References 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 DTCs before proceeding with this diagnostic.
With C99 Passenger Air Bag Disable Switch
1. Observe the scan tool Passenger Air Bag Disabled Switch parameter while commanding the passenger air bag ON and OFF by using the S40 passenger air bag disable switch. The value should change between On and Off. If the value does not change refer to Passenger Air Bag Disable Switch Circuit/System Testing.
• If the Passenger Air Bag Disabled Switch parameter does not change between On and Off
• Refer to Passenger Air Bag Disable Switch Circuit/System Testing.
• If the Passenger Air Bag Disabled Switch parameter does change between On and Off
2. All OK.
With ALO Passenger Presence System
1. Ignition ON.
2. Passenger seat unoccupied.
3. Verify the scan tool Passenger Seat Occupancy Status parameter is Empty.
• If the Passenger Seat Occupancy Status parameter does not display Empty
• The Passenger Presence System Module has set a DTC. Refer to Diagnostic Trouble Code (DTC) List - Vehicle Diagnostic Trouble Code (DTC) List - Vehicle.
• If the Passenger Seat Occupancy Status parameter does display Empty
4. Passenger seat unoccupied.
5. Verify the passenger air bag OFF indicator is illuminated.
• If the passenger air bag OFF indicator is not illuminated
• Refer to Passenger Air Bag Indicator Circuit/System Testing.
• If the passenger air bag OFF indicator is illuminated
6. Passenger seat occupied.
7. Verify the scan tool Passenger Seat Occupancy Status parameter is Occupied.
• If the Passenger Seat Occupancy Status parameter does not display Occupied
• The Passenger Presence System Module has set a DTC. Refer to Diagnostic Trouble Code (DTC) List - Vehicle Diagnostic Trouble Code (DTC) List - Vehicle.
• If the Passenger Seat Occupancy Status parameter displays Occupied
8. Passenger seat occupied.
9. Verify the passenger air bag ON indicator is illuminated.
• If the passenger air bag ON indicator is not illuminated
• Refer to Passenger Air Bag Indicator Circuit/System Testing.
• If the passenger air bag ON indicator is illuminated
10. All OK.
Passenger Air Bag Disable Switch Circuit/System Testing (C99)
1. Ignition OFF.
2. Disconnect the harness connector at the S40 passenger air bag disable switch.
3. Test for less than 30 ohm between the ground circuit terminal 3 and ground.
• If 30 ohm or greater
1. Disconnect the harness connector at the K36 SDM.
2. Test for infinite resistance between the control circuit and ground.
• If less than infinite resistance, repair the short to ground on the circuit.
3. Test for less than 2 ohm in each control circuit end to end.
• If 2 ohm or greater, repair the open/high resistance in the circuit.
• If less than 2 ohm, replace the K36 SDM.
• If less than 30 ohm
4. Ignition ON, test for 4.75-5.25 V between the signal circuit terminal 1 and ground.
• If less than 4.75 V
1. Disconnect the harness connector at the K36 SDM.
2. Test for infinite resistance between the control circuit and ground.
• If less than infinite resistance, repair the short to ground on the circuit.
3. Test for less than 2 ohm in each control circuit end to end.
• If 2 ohm or greater, repair the open/high resistance in the circuit.
• If less than ohm, replace the K36 SDM.
• If greater than 5.25 V
1. Ignition OFF.
2. Disconnect the harness connector at the K36 SDM.
3. Ignition ON.
4. Test for less than 1 V between the control circuit and ground:
• If 1 V or greater, repair the short to voltage on the circuit.
• If less than 1 V, replace the K36 SDM.
• If between 4.75-5.25 V
• Replace the S40 passenger air bag disable switch.
Passenger Air Bag Indicator Circuit/System Testing (ALO)
Note: removing connectors inspect for damage or corrosion. Damage or corrosion in the following requires repair or replacement of the affected.
* P14 Passenger Air Bag Indicator.
* P14 Passenger Air Bag Indicator wiring harness.
1. Ignition OFF.
2. Disconnect the harness connector at the P14 Passenger Air Bag Indicator.
3. Test for less than 5 ohm between the ground circuit terminal 2 and ground.
• If 5 ohm or greater
1. Disconnect the harness connector at the K36 SDM.
2. Test for less than 2 ohm in each control circuit end to end.
• If 2 ohm or greater, repair the open/high resistance in the circuit.
• If less than 2 ohm, replace the K36 SDM.
• If less than 5 ohm
4. Ignition ON.
5. Passenger seat occupied.
6. Test for less than 11 V between the control circuit terminal 3 and ground.
• If 11 V or greater
1. Ignition OFF.
2. Disconnect the harness connector at the K36 SDM.
3. Ignition ON.
4. Test for less than 1 V between the control circuit and ground.
• If 1 V or greater, repair the short to voltage on the circuit.
• If less than 1 V, replace the K36 SDM.
• If less than 11 V
7. Passenger seat unoccupied.
8. Test for greater than 25 ohm between the control circuit terminal 3 and ground.
• If 25 ohm or less
1. Disconnect the harness connector at the K36 SDM.
2. Test for infinite resistance between the control circuit and ground.
• If less than infinite resistance, repair the short to ground on the circuit.
3. Test for less than 2 ohm in each control circuit end to end.
• If 2 ohm or greater, repair the open/high resistance in the circuit.
• If less than 2 ohm, replace the K36 SDM.
• If greater than 25 ohm
9. Passenger seat unoccupied.
10. Test for less than 11 V between the control circuit terminal 1 and ground.
• If 11 V or greater
1. Ignition OFF.
2. Disconnect the harness connector at the K36 SDM.
3. Ignition ON.
4. Test for less than 1 V between the control circuit and ground.
• If 1 V or greater, repair the short to voltage on the circuit.
• If less than 1 V, replace the K36 SDM.
• If less than 11 V
11. Passenger seat occupied.
12. Test for greater than 25 ohm between the control circuit terminal 1 and ground.
• If 25 ohm or less
1. Disconnect the harness connector at the K36 SDM.
2. Test for infinite resistance between the control circuit and ground.
• If less than infinite resistance, repair the short to ground on the circuit.
3. Test for less than 2 ohm in each control circuit end to end.
• If 2 ohm or greater, repair the open/high resistance in the circuit.
• If less than 2 ohm, replace the K36 SDM.
• If greater than 25 ohm
13. Replace the P14 Passenger Air Bag Indicator.
Repair Instructions
* Perform the Diagnostic Repair Verification Verification Tests
* Inflatable Restraint Instrument Panel Module Indicator Replacement Service and Repair
* Control Module References Control Module References