B1131 & B1161 Airbag Codes

[gmwa_pro]

Been having B1131 and B1161 as active codes on my 98 STS and the Airbag light is on about 70% of the time......any thoughts would be appreciated.

Jeff

[gmwa_pro]

just found my own answer...B1131 is "Pass. Side Pretensioner Loop Resistance High" and B1161 is "Lamp Circuit Failure" for the Airbag light....FYI

[Logan]

B1131:

When you first turn the ignition switch to the ON position, the inflatable restraint sensing and diagnostic module (SDM) perform tests to diagnose critical malfunctions within itself. Next the SDM measures Ignition 1 and the deployment loop voltages to make sure they are within their respective normal voltage ranges. Then the SDM proceeds with the Resistance Measurement test. During one portion of the Resistance Measurement test, the SDM does the following:

Grounds the Passenger Pretensioner Low terminal 11 through an internal current sink.

Connects the Passenger Pretensioner High terminal 12 to an internal constant current source. This current produces proportional voltage drops in the deployment loop.

Measures the voltage difference between Passenger Pretensioner High and Passenger Pretensioner Low.

Calculates the resistance of the passenger pretensioner deployment loop using the measured voltage.

Conditions for Setting the DTC

The passenger and driver pretensioner deployment loops are not open.

The passenger and driver pretensioner deployment loops are not shorted to voltage.

The passenger and driver pretensioner deployment loops are not shorted to ground.

The passenger pretensioner deployment loop resistance is more than 3.1 ohms. The passenger pretensioner deployment loop consists of the following components:

Passenger seat belt pretensioner.

Harness wiring of CKT 2116.

Harness wiring of CKT 2117.

Connector terminal contact.

The Resistance Measurement test checks for this malfunction. This test only occurs once each ignition cycle when Ignition 1 is within the normal operating voltage range.

Action Taken When the DTC Sets

The SDM sets a Diagnostic Trouble Code (DTC).

The SDM commands the instrument cluster (IPC) to turn ON the AIR BAG warning lamp.

Conditions for Clearing the MIL/DTC

Current DTC The resistance of the passenger pretensioner deployment loop is less than 3.1 ohms and the ignition switch is cycled.

History DTC

You issue a scan tool Clear DTCs command.

Once 250 malfunction free ignition cycles have occurred.

When you issue a scan tool Clear DTCs command and the malfunction is still present, the DTC will not reappear until the next ignition cycle.

Diagnostic Aids

A poor connection can cause an intermittent condition. Check the following for a poor connection:

The side air bag/pretensioner yellow 6-way harness connector terminals A and F.

The SDM terminals 12 and 11.

The wire to terminal connections in CKT 2116.

The wire to terminal connections in CKT 2117.

When measurements are requested in this table, use J 39200 Digital Multimeter with the correct terminal adapter from J 35616-A Connector Test Adapter Kit. When a check for proper connection is requested, refer to General Electrical Diagnosis Procedures in Wiring Systems. When a wire, connector or terminal repair is requested, use J 38125-B Terminal Repair Kit and refer to Wiring Repair .

Test Description

The numbers below refer to the step numbers on the diagnostic table:

This test checks for proper contact or corrosion of the side air bag/pretensioner yellow 6-way connector.

This test isolates the malfunction to one side of the side air bag/pretensioner yellow 6-way connector.

This test determines if the malfunction is in the jumper harness or the pretensioner.

This test checks for proper contact or corrosion of the SDM connector.

This test determines whether the malfunction is in CKT 2116.

This test determines whether the malfunction is in CKT 2117.

B1161

The instrument cluster (IPC) sends a message over class 2 serial data line to the inflatable restraint sensing and diagnostic module (SDM) if the IPC cannot turn the AIR BAG warning lamp ON or OFF.

Conditions for Setting the DTC

If the SDM receives a message from the IPC that the IPC cannot control the AIR BAG warning lamp. This test is run Asynchronously during Continuous Monitoring by the IPC.

Action Taken When the DTC Sets

The SDM sets a Diagnostic Trouble Code (DTC).

Conditions for Clearing the MIL/DTC

Current DTC

The ignition switch is turned to OFF.

The SDM receives the IPC message response over class 2 serial data line.

History DTC

You issue a scan tool Clear DTCs command.

Once 250 malfunction free ignition cycles have occurred.

Diagnostic Aids

It is unlikely that the SDM is malfunctioning if DTC B1161 is set. A malfunctioning IPC is the most likely cause of this DTC.

When measurements are requested in this table, use J 39200 Digital Multimeter with the correct terminal adapter from J 35616-A Connector Test Adapter Kit. When a check for proper connection is requested, refer to General Electrical Diagnosis Procedures in Wiring Systems. When a wire, connector or terminal repair is requested, use J 38125-B Terminal Repair Kit and refer to Wiring Repair .

CAUTION

Be careful when you handle a sensing and diagnostic module (SDM). Do not strike or jolt the SDM. Before applying power to the SDM:

Remove any dirt, grease, etc. from the mounting surface

Position the SDM horizontally on the mounting surface

Point the arrow on the SDM toward the front of the vehicle

Tighten all of the SDM fasteners and SDM bracket fasteners to the specified torque value

Failure to follow the correct procedure could cause air bag deployment, personal injury, or unnecessary SIR system repairs.