GM Service Manual Online
For 1990-2009 cars only

Object Number: 417329  Size: SF
SIR Components
SIR Schematics
Handling ESD Sensitive Parts Notice
SIR Caution

Circuit Description

When you first turn the ignition switch to the RUN position, the inflatable restraint sensing and diagnostic module (SDM) performs tests to diagnose critical malfunctions within itself. Upon passing these tests IGNITION, 23 VLR 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 Belt Low terminal 9 and Passenger Belt Low terminal 15 to detect shorts to B+ in the seat belt pretensioner deployment loops circuits.

Conditions for Setting the DTC

    • The voltage at Driver Belt Low terminal 9 is more than 4.5 volts for 500 milliseconds.
    • The voltage at Passenger Belt Low terminal 15 is less than 3.5 volts.

The CONTINUOUS MONITORING test checks for this DTC. This test occurs when IGNITION is within the normal operating voltage range.

Action Taken When the DTC Sets

    • The SDM sets a DTC B1044.
    • The SDM turns ON the AIR BAG warning lamp.

Conditions for Clearing the DTC

    • Current DTC
        The voltage at Driver Belt Low terminal 9 is less than 3.5 volts for 500 milliseconds.
    • History DTC
       - You issue a scan tool CLEAR CODES command.
       - Once 250 malfunction free ignition cycles have occurred.

Diagnostic Aids

A short to B+ in the driver seat belt pretensioner deployment loop circuit can cause an intermittent condition. Inspect CKT 2118 and CKT 2119 carefully for cutting or chafing. Wiring pigtail damage requires replacement of the passenger seat belt pretensioner. The diagnostic table directs the technician to note the entry value of LH PRETENS. SENSELO. Comparing the value of LH PRETENS. SENSELO 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 Intermittents and Poor Connections . 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 step isolates the malfunction to one side of the driver seat belt pretensioner yellow 2-way connector.

  2. This step checks to see if there is a short to B+ in CKT 2118.

  3. This step checks to see if there is a short to B+ in CKT 2119 or if there is a malfunctioning SDM.

DTC B1044 Driver Seat Belt Pretensioner Deployment Loop Short to Voltage

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 to the OFF position.
  2. Install the scan tool.
  3. Turn the ignition switch to the RUN position.
  4. Use the scan tool to request the SIR data list display.
  5. Read and record on the repair order the driver seat belt pretensioner low voltage LH PRETENS. SENSELO.

Has the LH PRETENS. SENSELO been read and recorded on the repair order?

--

Go to Step 3

--

3

  1. Turn the ignition switch to the OFF position.
  2. Disconnect the inflatable restraint front side impact module (LH) and driver seat belt pretensioner yellow 2-way connectors.
  3. Connect the J 38715-A SIR Driver/Passenger Load Tool STEERING COLUMN and PASSENGER INFLATOR connectors to the yellow 2-way wiring harness connectors.
  4. Turn the ignition switch to the RUN position.
  5. Use the scan tool to request the SIR data list display.
  6. Read the driver seat belt pretensioner low voltage LH PRETENS. SENSELO.

Is LH PRETENS. SENSELO more than the specified value?

4.5 V

Go to Step 5

Go to Step 4

4

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

Is the repair complete?

--

Go to Step 9

--

5

  1. Turn the ignition switch to the OFF position.
  2. Disconnect the inflatable restraint sensing and diagnostic module (SDM). Refer to Inflatable Restraint Sensing and Diagnostic Module Replacement .
  3. Disconnect the J 38715-A .
  4. Insert the J 42113 SIR Shorting Bar Tool into the SDM wiring harness connector above terminal 8 and terminal 9.
  5. Turn the ignition switch to the RUN position.
  6. Use the J 39200 Digital Multimeter (DMM) to measure the voltage between terminal A of the driver seat belt pretensioner yellow 2-way wiring harness connector and a known good ground.

Is the measured voltage less than the specified value?

1 V

Go to Step 7

Go to Step 6

6

  1. Locate a short to B+ in CKT 2118.
  2. Repair the short to B+ in CKT 2118.

Is the repair complete?

--

Go to Step 9

--

7

Use the J 39200 to measure the voltage between terminal B of the driver seat belt pretensioner yellow 2-way wiring harness connector and a known good ground.

Is the measured voltage less than the specified value?

1 V

Go to Sensing and Diagnostic Module Integrity Check

Go to Step 8

8

  1. Locate a short to B+ in CKT 2119.
  2. Repair the short to B+ in CKT 2119.

Is the repair complete?

--

Go to Step 9

--

9

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

Have all the SIR components been reconnected and properly mounted?

--

Go to Step 10

--

10

Use the scan tool to clear all current and history SIR DTCs.

Have all current and history SIR DTCs been cleared?

--

Go to SIR Diagnostic System Check

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