GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Cadillac 🢒 1998 🢒 Seville 🢒 Restraints 🢒 SIR 🢒 DTC B1145 Driver/Pass Pretens. Loop Short to Volt

Object Number: 261382 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. Upon passing these tests Ignition 1, 23VLR and the deployment loop voltages are measured to make sure they are within their respective normal voltage ranges. The SDM monitors the voltages at Driver Pretensioner Low terminal 23 and Passenger Pretensioner Low terminal 11 to detect shorts to voltage in the pretensioner deployment circuits.

Conditions for Setting the DTC

The voltage at Driver Pretensioner Low terminal 23 or, Passenger Pretensioner Low terminal 11, is more than 4.0 volts for 500 milliseconds. The following tests check for this DTC. These tests occur when Ignition 1 is within the normal operating voltage range.

    • Power-On--When 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
    • The voltage measured at Driver Pretensioner Low and Passenger Pretensioner Low is below 4.0 volts for 500 milliseconds.
    • The ignition switch is turned OFF.

Diagnostic Aids

A short-to-voltage in the passenger pretensioner circuit or the driver pretensioner circuit can cause an intermittent condition. Moving wires while monitoring Driver Pretensioner Senselo and Passenger Pretensioner Senselo may help to locate the fault. Inspect CKT 2116, CKT 2117, CKT 2118, and CKT 2119 carefully for cutting or chafing. The diagnostic table directs the technician to note the entry value of Driver Pretensioner Senselo and Passenger Pretensioner Senselo. Noting the value of Driver Pretensioner Senselo and Passenger Pretensioner Senselo during diagnosis 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 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 determines the driver pretensioner voltage measured by the inflatable restraint sensing and diagnostic module (SDM) and if the malfunction is currently occurring.

    2.

  2. This test isolates the malfunction to one side of the driver 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 determines whether the malfunction is in CKT 2118.

    5.

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

    6.

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

    7.

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

    8.

  8. This test determines whether the malfunction is in CKT 2117.

    9.

  9. This test determines whether the malfunction is in CKT 2116.

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 Senselo.

Is Driver Pretensioner Senselo more than the specified value?

4.0 V

Go to Step 3

Go to Step 19

3

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

Is Driver Pretensioner Senselo more than the specified value?

4.0 V

Go to Step 7

Go to Step 4

4

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

Is DTC B1145 current?

--

Go to Step 5

Go to Step 6

5
  1. Turn the ignition switch to OFF.
  2. Replace the driver seat belt pretensioner jumper harness. Refer to Pretensioner Wiring Harness Replacement .

Have the repairs been completed?

--

Go to Step 20

--

6
  1. Turn the ignition switch OFF
  2. Inspect the driver pretensioner jumper harness for damage and proper routing.
  3. Replace the driver seat belt pretensioner. Refer to Seat Belt Buckle Pretensioner Replacement - Left Side .

Have the repairs been completed?

--

Go to Step 20

--

7

  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. Using J 39200 DMM, measure the voltage between terminals 18 and 24 of SDM harness connector.

Is the voltage reading more than the specified value?

0.5 V

Go to Step 8

Go to Step 9

8

Repair a short to voltage condition in CKT 2118.

Have the repairs been completed?

--

Go to Step 20

--

9

Using J 39200 DMM, measure the voltage between terminals 18 and 23 of SDM harness connector.

Is the voltage reading more than the specified value?

0.5 V

Go to Step 10

Go to Step 11

10

Repair a short to ground condition in CKT 2119.

Are the repairs complete?

--

Go to Step 20

--

11

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

Is Passenger Pretensioner Senselo more than the specified value?

4.0 V

Go to Step 15

Go to Step 12

12

  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 pretensioner.
  5. Disconnect the passenger seat belt pretensioner yellow 2-way connector.
  6. Connect the J 38715-A Load Tool to the jumper harness connector.
  7. Turn the ignition switch to ON.

Is DTC B1145 current?

--

Go to Step 13

Go to Step 14

13
  1. Turn the ignition switch to OFF.
  2. Replace the passenger seat belt pretensioner jumper harness. Refer to Pretensioner Wiring Harness Replacement .

Have the repairs been completed?

--

Go to Step 20

--

14
  1. Turn the ignition switch OFF.
  2. Inspect the passenger pretensioner pigtail for damage and proper routing.
  3. Replace the passenger seat belt pretensioner. Refer to Seat Belt Buckle Pretensioner Replacement - Right Side .

Have the repairs been completed?

--

Go to Step 20

--

15

  1. Turn the ignition switch OFF.
  2. Disable the frontal SIR and the 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. Using J 39200 DMM, measure the voltage between terminals 11 and 18 of SDM harness connector.

Is the voltage more than the specified value?

0.5 V

Go to Step 16

Go to Step 17

16

Repair a short to voltage condition in CKT 2117.

Have the repairs been completed?

--

Go to Step 20

--

17

Using J 39200 DMM, measure the voltage between terminals 12 and 18 of SDM harness connector.

Is the voltage more than the specified value?

0.5 V

Go to Step 18

Go to Step 19

18

Repair a short to voltage condition in CKT 2116.

Have the repairs been completed?

--

Go to Step 20

--

19

An intermittent short to ground condition caused DTC B1145 to set. Use the Diagnostic Aids for DTC B1145 and the DTC B1145 table to find the intermittent short to ground.

Has the intermittent short to ground been found and repaired?

--

Go to Step 20

--

20
  1. Reconnect all the SIR system components, make sure all the components are properly mounted.
  2. Turn the ignition switch to ON.
  3. Make sure that Passenger Pretensioner Senselo and Driver Pretensioner Senselo are less than the specified value.

Have all the SIR components been reconnected and properly mounted?

4.0 V

Go to SIR Diagnostic System Check

--