GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Cadillac 🢒 1998 🢒 Seville 🢒 DTC 🢒 DTC B1122 Driver Deployment Loop Resistance Low

Object Number: 261351 Size: MF
SIR Components
SIR Schematics
SIR Handling Caution
Handling ESD Sensitive Parts Notice
SIR Schematic Icons
SIR Schematic Icons

Circuit Description

When you first turn the ignition switch to the ON position, the inflatable restraint Sensing and Diagnostic Module (SDM) performs 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 Driver Frontal Low terminal 9 through an internal current sink.
    • Connects the Driver Frontal High terminal 10 to an internal constant current source. This current produces proportional voltage drops in the deployment loop.
    • Measures the voltage difference between Driver Frontal High and Driver Frontal Low.
    • Calculates the resistance of the driver frontal deployment loop using the measured voltage.

Conditions for Setting the DTC
    • The driver and passenger frontal and pretensioner deployment loops are not open.
    • The driver and passenger frontal deployment loops are not shorted to voltage.
    • The driver and passenger frontal deployment loops are not shorted to ground.
    • The driver frontal deployment loop resistance is less than 1.7 ohms. The driver frontal deployment loop consists of the following components:
       - Inflatable restraint steering wheel module.
       - Inflatable restraint steering wheel module coil.
       - Harness wiring of CKT 347.
       - Harness wiring of CKT 348.
       - 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 driver frontal deployment loop is more than 1.7 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

The following can cause an intermittent condition:

    • A short circuit between CKT 347 and CKT 348.
    • A short circuit between CKT 347 and CKT 1403.
    • A short circuit between CKT 347 and CKT 1404.
    • A malfunctioning shorting bar on the inflatable restraint steering wheel module connector.
    • A malfunctioning shorting bar on the inflatable restraint steering wheel module coil steering column connector.

When measurements are requested in this table, use J 39200 Digital Multimeter with the correct terminal adapter from J 35616 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 Terminal Repair Kit and refer to Wiring Repair .

Test Description

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

  1. This test checks for a short from the Passenger Frontal High circuit to the Driver Frontal High circuit.

    2.

  2. This test isolates the malfunction to one side of the inflatable restraint steering wheel module coil yellow 2-way connector.

    3.

  3. This test determines whether the malfunction is due to the inflatable restraint steering wheel module or the module coil.

    4.

  4. This test checks for a short from CKT 347 to CKT 348.

    5.

  5. This test checks for a short from CKT 347 to CKT 1404.

Step

Action

Value(s)

Yes

No

1

Was the SIR Diagnostic System Check performed?

--

Go to Step 2

Go to SIR Diagnostic System Check

2

  1. Turn the ignition switch OFF.
  2. Connect a scan tool to the DLC.
  3. Turn the ignition switch to ON.
  4. Request the SIR DTC display.

Is DTC B1116 also present?

--

Go to Step 3

Go to Step 4

3
  1. Turn the ignition switch OFF.
  2. Disconnect the inflatable restraint steering wheel and IP module yellow 2-way connectors at the base of the steering column and above the passenger side sound insulator.
  3. Repair the short from CKT 347 to CKT 1403. Refer to Wiring Repair .

Have the repairs been completed?

--

Go to Step 13

--

4

  1. Turn the ignition switch OFF.
  2. Disconnect the inflatable restraint steering wheel module yellow 2-way connector at the base of the steering column and above the passenger side sound insulator.
  3. Reconnect the 2-way connector.
  4. Inspect that the CPA is properly installed.
  5. Turn the ignition switch to ON.
  6. Using a scan tool, request the SIR DTC display.

Is DTC B1122 current?

--

Go to Step 5

Go to Step 13

5

  1. Turn the ignition switch OFF.
  2. Disconnect the inflatable restraint steering wheel and IP module yellow 2-way connectors at the base of the steering column and above the passenger side sound insulator.
  3. Connect the J 38715-A Load Tool to the harness connectors.
  4. Turn the ignition switch to ON.

Is DTC B1122 current?

----

Go to Step 9

Go to Step 6

6
  1. Turn the ignition switch OFF.
  2. Remove the inflatable restraint steering wheel module. Refer Supplemental Restraint Steering Wheel Module Replacement .
  3. Disconnect the J 38715-A Load Tool from the driver 2-way connector.
  4. Connect the 2-way connector at the base of the steering column.
  5. Connect the J 38715-A Load Tool to the upper inflatable restraint steering wheel module coil connector on the steering column.
  6. Turn the ignition switch to ON.

Is DTC B1122 current?

----

Go to Step 8

Go to Step 7

7
  1. Turn the ignition switch OFF.
  2. Replace the inflatable restraint steering wheel module. Refer Supplemental Restraint Steering Wheel Module Replacement .

Have the repairs been completed?

--

Go to Step 13

--

8
  1. Turn the ignition switch OFF.
  2. Replace the inflatable restraint steering wheel module coil. Refer Inflatable Restraint Steering Wheel Module Coil Replacement .

Have the repairs been completed?

--

Go to Step 13

--

9
  1. Turn the ignition switch OFF.
  2. Disconnect the inflatable restraint sensing and diagnostic module (SDM).
  3. Disconnect the J 38715-A Load Tool.
  4. Using J 39200 DMM, measure the resistance between terminals 9 and 10 of the SDM harness connector.

Is the resistance reading less than the specified value?

OL

Go to Step 10

Go to Step 11

10

Repair a short from CKT 347 to CKT 348. Refer to Wiring Repair .

Have the repairs been completed?

--

Go to Step 13

--

11

Using J 39200 DMM, measure the resistance between terminals 8 and 10 of the SDM harness connector.

Is the resistance reading less than the specified value?

OL

Go to Step 12

Go to Sensing and Diagnostic Module Integrity Check

12

Repair a short from CKT 347 to CKT 1404. Refer to Wiring Repair .

Have the repairs been completed?

--

Go to Step 13

--

13

Reconnect all the SIR system components, make sure all the components are properly mounted.

Have all the SIR components been reconnected and properly mounted?

--

Go to Step 14

--

14

Clear all the SIR DTCs. Refer to Diagnostic Trouble Code (DTC) Clearing in Wiring Systems.

Have all the SIR DTCs been cleared?

--

Go to SIR Diagnostic System Check

--