GM Service Manual Online
For 1990-2009 cars only

Object Number: 420619  Size: SF
SIR Components
Cell 47: SIR Diagnostic Module, Seat Belt Switch
SIR Caution
Handling ESD Sensitive Parts Notice

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. Next the SDM measures IGNITION 1 voltage to make sure 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 PASSENGER SIDE HIGH and PASSENGER SIDE LOW.

Conditions for Setting the DTC

    • The voltage difference between PASSENGER SIDE HIGH terminal 1 and PASSENGER SIDE LOW terminal 4 is more than or equal to 400 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 DTC B1017.
    • The SDM turns ON the AIR BAG warning lamp.

Conditions for Clearing the DTC

    • Current DTC
        The voltage difference between PASSENGER SIDE HIGH terminal 1 and PASSENGER SIDE LOW terminal 4 is less than 400 millivolts for 500 milliseconds.
    • History DTC
       - You issue a scan tool CLEAR CODES command.
       - Once 250 malfunction free ignition cycles have occurred.

Diagnostic Aids

The following can cause an intermittent condition:

    • A poor connection at the inflatable restraint IP module connector terminal A and terminal B.
    • A poor connection at the SDM wiring harness connector terminal 1 and terminal 4.
    • An open in CKT 1403.
    • An open in CKT 1404.

When measurements are requested in this table, use the J 39200 DMM with the correct terminal adapter from the J 35616 Connector Test Adapter Kit. When an inspection for proper connection is requested, refer to Testing for Electrical Intermittents in Wiring Systems. When a wire, connector or terminal repair is requested, use the J-38125 Terminal Repair Kit and refer to Wiring Repairs in Wiring Systems.

Test Description

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

  1. This step checks the passenger deployment loop voltage difference that was measured by the inflatable restraint sensing and diagnostic module (SDM).

  2. This step checks to see if the inflatable restraint IP module yellow 2-way connector is corroded or damaged.

  3. This step isolates the malfunction to one side of the inflatable restraint IP module yellow 2-way connector.

  4. This step checks the SDM wiring harness connector for corrosion or damaged terminals.

  5. This step checks to see if there is an open in CKT 1403.

  6. This step determines if there is an open in CKT 1404 or if there is a malfunctioning SDM.

DTC B1017 Passenger Deployment Loop Open

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 scan tool data list.
  5. Read and record on the repair order the passenger deployment loop voltage difference PASSENGER VDIF.

Has the PASSENGER VDIF 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 steering wheel module coil and IP module yellow 2-way wiring harness connectors.
  3. Check for a proper connection at terminal A and terminal B on the wiring harness side of the inflatable restraint IP module yellow 2-way connector.

Are the terminals damaged or corroded?

--

Go to Step 4

Go to Step 6

4

Replace the inflatable restraint IP module yellow 2-way wiring harness connector. Refer to Wiring Repair .

Is the repair complete?

--

Go to Step 5

--

5

Check for proper connection at terminal A and terminal B on the inflatable restraint IP module yellow 2-way connector.

Are the terminals damaged or corroded?

--

Go to Step 7

Go to Step 21

6

Check for proper connection at terminal A and terminal B on the inflatable restraint IP module yellow 2-way connector.

Are the terminals damaged or corroded?

--

Go to Step 7

Go to Step 8

7

Replace the inflatable restraint IP module. Refer to Inflatable Restraint Instrument Panel Module Replacement .

Is the repair complete?

--

Go to Step 21

--

8

  1. Connect the inflatable restraint steering wheel module coil and IP module yellow 2-way wiring harness connectors.
  2. Turn the ignition switch to the RUN position.
  3. Use the scan tool to request the SIR scan tool data list.
  4. Read the passenger deployment loop voltage difference PASSENGER VDIF.

Is the PASSENGER VDIF less than the specified value?

400 mV

Go to Step 9

Go to Step 10

9

  1. Turn the ignition switch to the OFF position.
  2. Replace the inflatable restraint IP module yellow 2-way wiring harness connector. Refer to Wiring Repair .

Is the repair complete?

--

Go to Step 21

--

10

  1. Turn the ignition switch to the OFF position.
  2. Disconnect the inflatable restraint steering wheel module coil and IP module yellow 2-way wiring harness connectors.
  3. Connect the J 38715-A SIR Driver/Passenger Load Tool to the IP wiring harness connectors.
  4. Turn the ignition switch to the RUN position.
  5. Use the scan tool to request the SIR scan tool data list.
  6. Read the passenger deployment loop voltage difference PASSENGER VDIF.

Is the PASSENGER VDIF less than the specified value?

400 mV

Go to Step 11

Go to Step 12

11

  1. Turn the ignition switch to the OFF position.
  2. Replace the inflatable restraint IP module. Refer to Inflatable Restraint Instrument Panel Module Replacement .

Is the repair complete?

--

Go to Step 21

--

12

  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. Remove the J 38715-A from the IP wiring harness connectors.
  4. Check for a proper connection at terminal 1 and terminal 4 of the SDM wiring harness connector.

Is the SDM wiring harness connector damaged or corroded?

--

Go to Step 13

Go to Step 15

13

Replace the SDM wiring harness connector. Refer to Wiring Repair .

Is the repair complete?

--

Go to Step 14

--

14

Check for a proper connection at terminal 1 and terminal 4 of the SDM.

Are the SDM terminals damaged or corroded?

--

Go to Step 16

Go to Step 21

15

Check for a proper connection at terminal 1 and terminal 4 of the SDM.

Are the SDM terminals damaged or corroded?

--

Go to Step 16

Go to Step 17

16

Replace the SDM. Refer to Inflatable Restraint Sensing and Diagnostic Module Replacement .

Is the repair complete?

--

Go to Step 21

--

17

  1. Zero the J 39200 Digital Multimater (DMM).
  2. Use the J 39200 to measure the resistance between terminal 1 of the SDM wiring harness connector and terminal A of the inflatable restraint IP module yellow 2-way wiring harness connector.

Is the measured resistance within the specified value?

0-0.5 ohms

Go to Step 19

Go to Step 18

18

  1. Locate an open in CKT 1403.
  2. Repair the open in CKT 1403.

Is the repair complete?

--

Go to Step 21

--

19

Use the J 39200 to measure the resistance between terminal 4 of the SDM wiring harness connector and terminal B of the inflatable restraint IP module yellow 2-way wiring harness connector.

Is the measured resistance within the specified value?

0-0.5 ohms

Go to Sensing and Diagnostic Module Integrity Check

Go to Step 20

20

  1. Locate an open in CKT 1404.
  2. Repair the open in CKT 1404.

Is the repair complete?

--

Go to Step 21

--

21

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 22

--

22

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

--