GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Cadillac 🢒 1999 🢒 Seville 🢒 DTC 🢒 DTC B1146 Driver Pretensioner Loop Open

Object Number: 142295 Size: MF
SIR Components
SIR Schematics
SIR Handling Caution
Handling ESD Sensitive Parts Notice
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 in order to diagnose critical malfunctions within itself. Next the SDM measures Ignition 1 voltage in order to ensure that it is within its respective normal voltage range. Then the SDM proceeds with the Deployment Loop Continuity test. During the Deployment Loop Continuity test, the SDM measures the voltage difference between Driver Pretensioner High and Driver Pretensioner Low.

Conditions for Setting the DTC
    • The voltage difference between Driver Pretensioner High terminal 24 and Driver Pretensioner Low terminal 23 is more than or equal to 426 millivolts.
    • The malfunction must be present for at least 500 milliseconds during one of the following tests:
       - Deployment Loop Continuity
       - If the malfunction is detected in this test, the Resistance Measurement test will not be performed.
       - Continuous Monitoring

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 voltage difference between Driver Pretensioner High  24 and Driver Pretensioner Low terminal 23 is less than 426 millivolts for 500 milliseconds.
    • History DTC
       - You issue a scan tool Clear DTCs command.
       - Once 250 malfunction free ignition cycles have occurred.

Diagnostic Aids

The following can cause an intermittent condition:

    • A poor connection at the driver side air bag/pretensioner harness connector terminals A and F.
    • A poor connection at the SDM terminals 23 and 24.
    • An open in CKT 2119.
    • An open in CKT 2118.

The diagnostic table directs the technician to note the scan tool value of Driver Pretensioner VDIF Comparing the value of Driver Pretensioner VDIF can be helpful in determining if an intermittent condition exists.

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 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 determines the deployment loop voltage difference measured by the inflatable restraint sensing and diagnostic module (SDM).

    2.

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

    3.

  3. This test isolates the malfunction to the jumper harness or the pretensioner.

    4.

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

    5.

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

    6.

  6. This test determines whether the malfunction is in CKT 2119.

    7.

  7. This test determines whether the malfunction is in CKT 2118.

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 data list display. Refer to Scan Tool Data List .
  5. Read and record on the repair order the Driver Pretensioner VDIF.

Has the Driver Pretensioner VDIF been read and recorded on the repair order?

--

Go to Step 3

--

3

  1. Turn the ignition switch OFF.
  2. Disconnect the driver side air bag/pretensioner yellow 6-way connector located under the driver front seat.
  3. Check for proper connection at terminals A and F on the harness side of the driver side air bag/pretensioner 6-way connector.

Are the terminals damaged or corroded?

--

Go to Step 4

Go to Step 6

4

Replace the driver side air bag/pretensioner yellow 6-way harness connector. Refer to Wiring Repair .

Did you complete the repair?

--

Go to Step 5

--

5

Check for proper connection at terminals A and F on the driver side air bag/pretensioner yellow 6-way connector.

Are the terminals damaged or corroded?

--

Go to Step 7

Go to Step 23

6

Check for proper connection at terminals A and F on the driver side air bag/pretensioner yellow 6-way connector.

Are the terminals damaged or corroded?

--

Go to Step 7

Go to Step 8

7

Replace the driver seat belt pretensioner. Refer to Seat Belt Buckle Pretensioner Replacement - Left Side .

Did you complete the replacement?

--

Go to Step 23

--

8
  1. Connect the driver side air bag/pretensioner yellow 6-way connector.
  2. Turn the ignition switch to ON.
  3. Using the scan tool, request the SIR data list display. Refer to Scan Tool Data List .
  4. Read the Driver Pretensioner VDIF.

Is the Driver Pretensioner VDIF greater than the specified value?

426 mV

Go to Step 10

Go to Step 9

9
  1. Turn the ignition switch OFF.
  2. Replace the driver side air bag/pretensioner yellow 6-way harness connector. Refer to Wiring Repair .

Did you complete the repair?

--

Go to Step 23

--

10
  1. Turn the ignition switch OFF.
  2. Disconnect the driver side air bag/pretensioner yellow 6-way connector located under the driver front seat.
  3. Connect the J 38715-A SIR Driver/Passenger Load Tool at the connector.
  4. Turn the ignition switch to ON.
  5. Using the scan tool, request the data list display. Refer to Scan Tool Data List .
  6. Read the Driver Pretensioner VDIF.

Is the Driver Pretensioner VDIF greater than the specified value?

426 mV

Go to Step 14

Go to Step 11

11

  1. Turn the ignition switch to OFF.
  2. Disconnect the J 38715-A Load Tool.
  3. Reconnect the passenger side air bag/pretensioner yellow 6-way connector.
  4. Remove the shrink wrap from the passenger seat belt buckle pretensioner.
  5. Connect the J 38715-A Load Tool to the jumper harness connector.
  6. Turn the ignition switch to ON.

Is DTC B1146 current?

--

Go to Step 12

Go to Step 13

12

  1. Turn the ignition switch to OFF.
  2. Replace the passenger seat belt pretensioner jumper harness. Refer to Pretensioner Wiring Harness Replacement .

Are the repairs complete?

--

Go to Step 23

--

13
  1. Turn the ignition switch OFF.
  2. Replace the driver seat belt pretensioner. Refer to Seat Belt Buckle Pretensioner Replacement - Left Side .

Did you complete the replacement?

--

Go to Step 23

--

14

  1. Turn the ignition switch OFF.
  2. Disable the frontal SIR and side air bag systems. Refer to Disabling the SIR System .
  3. Disconnect the inflatable restraint sensing and diagnostic module (SDM).
  4. Disconnect the J 38715-A Load Tool.
  5. Check for proper connection at terminals 24 and 23 on the SDM harness connector.

Is the connector damaged or corroded?

--

Go to Step 15

Go to Step 17

15

Replace the SDM harness connector. Refer to Connector Repairs in Wiring Systems.

Did you complete the repair?

--

Go to Step 16

--

16

Check for proper connection at terminals 24 and 23 of the SDM.

Are the terminals damaged or corroded?

--

Go to Step 18

Go to Step 23

17

Check for proper connection at terminals 24 and 23 of the SDM.

Are the terminals damaged or corroded?

--

Go to Step 18

Go to Step 19

18

Replace the inflatable restraint sensing and diagnostic module (SDM). Refer to Inflatable Restraint Sensing and Diagnostic Module Replacement .

Did you complete the replacement?

--

Go to Step 23

--

19

Using J 39200 DMM, measure the resistance from the SDM harness connector terminal 23 to the side air bag/pretensioner yellow 6-way harness connector terminal F.

Is the resistance reading within the specified values?

0.0-0.5 ohms

Go to Step 21

Go to Step 20

20

Repair the high resistance condition in CKT 2119. Refer to Wiring Repair .

Did you complete the repair?

--

Go to Step 23

--

21

Using J 39200 DMM, measure the resistance from the SDM harness connector terminal 24 to the side air bag/pretensioner yellow 6-way harness connector terminal A.

Is the resistance reading within the specified values?

0.0-0.5 ohms

Go to Sensing and Diagnostic Module Integrity Check

Go to Step 22

22

Repair the high resistance condition in CKT 2118. Refer to Wiring Repair .

Did you complete the repair?

--

Go to Step 23

--

23

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 24

--

24

Clear all the SIR DTCs.

Have all the SIR DTCs been cleared?

--

Go to SIR Diagnostic System Check

--