GM Service Manual Online
For 1990-2009 cars only

Object Number: 39349  Size: LF

Circuit Description

During the Continuous Monitoring tests the inflatable restraint Diagnostic Energy Reserve Module (DERM) monitors the voltage at the driver source sense terminal A5. When the circuit is operating normally, the measured voltage will be less than the Driver 36 VLR. If the Driver 36 VLR circuit opens, the voltage measured at the driver source sense will decrease to less than Ignition 1 voltage. When the voltage measured at the driver source sense is within a specified range of Ignition 1 for 500 milliseconds, DTC B1031 is set.

Conditions for Setting the DTC

The voltage measured at the Driver Source Sense terminal A5 is within a specified range of ignition 1 for 500 milliseconds during continuous monitoring.

Action Taken When the DTC Sets

The DERM turns on the AIR BAG warning lamp and sets a diagnostic trouble code.

Conditions for Clearing the DTC

The voltage measured at the Driver Source Sense terminal A5 is outside the specified range of Ignition 1 which sets the diagnostic trouble code, for 500 milliseconds.

Diagnostic Aids

An intermittent condition may be caused by one of the following:

    • A poor connection at the inflatable restraint arming sensor
    • A poor connection at the inflatable restraint arming sensor jumper harness electrical connector terminal B
    • A poor connection at the inflatable restraint arming sensor jumper harness electrical connector terminal C
    • A poor connection at the DERM terminal A4
    • A poor connection at the DERM terminal A5
    • An open in CKT 236
    • An open in CKT 1400
    • An open inside the inflatable restraint arming sensor

Test Description

  1. Start at the SIR Diagnostic System Check for all diagnosis.

  2. This test checks for an open in the Driver 36 VLR circuit between the DERM and the inflatable restraint arming sensor connector.

  3. This test checks for a open in the Driver 36 VLR circuit between the inflatable restraint arming sensor jumper harness connector and the Derm.

  4. This test checks for high resistance, but not an open, in the Driver Source Sense circuit between the DERM and inflatable restraint arming sensor electrical harness connector.

  5. This test checks for high resistance, but not an open, in the Driver Source Sense circuit between the DERM and the inflatable restraint arming sensor jumper harness electrical connector C110.

  6. This test checks for a short from the Driver Source Sense circuit to B+.

When measurements are requested in this table, use J 39200 Digital Multimeter with correct terminal adapter from J 35616 Connector Test Adapter Kit. When a check for proper connection is requested, refer to Intermittents and Poor Connections in Section 8A4. When a wire, connector or terminal repair is requested, use J-38125 Terminal Repair Kit and refer to Wiring Repair.

DTC B1031- Driver Loop Energy Reserve Feed Open

Step

Action

Value

Yes

No

1

Was the SIR Diagnostic System Check performed?

--

Go to Step 2

Go to SIR Diagnostic System Check

2

  1. Turn OFF the ignition switch.
  2. Disconnect the yellow 2-way electrical connector C214 at the base of the steering column.
  3. Disconnect the inflatable restraint arming sensor.
  4. Check for proper connection to the inflatable restraint arming sensor at terminals B and C.

Is the inflatable restraint arming sensor electrical harness connector damaged or corroded?

--

Go to Step 3

Go to Step 4

3

Replace the inflatable restraint arming sensor electrical harness connector.

Has the connector been replaced?

--

Go to Step 5

--

4

Check for proper connection to the inflatable restraint arming sensor at terminals B and C.

Are the inflatable restraint arming sensor terminals damaged or corroded?

--

Go to Step 6

Go to Step 7

5

Check for proper connection to the inflatable restraint arming sensor at terminals B and C.

Are the inflatable restraint arming sensor terminals damaged or corroded?

--

Go to Step 6

Go to Step 27

6

Replace the inflatable restraint arming sensor. Refer to Inflatable Restraint Arming Sensor .

Has the inflatable restraint arming sensor been replaced?

--

Go to Step 27

--

7

  1. Disconnect the DERM.
  2. Check for proper connection to the DERM at terminals A4 and A5.

Is the DERM electrical harness connector damaged or corroded?

--

Go to Step 8

Go to Step 9

8

Repair the DERM electrical harness connector.

Has the connector been repaired?

Go to Step 10

9

Check for proper connection to the DERM at terminals A4 and A5.

Are the DERM terminals damaged or corroded?

Go to Step 11

Go to Step 12

10

Check for proper connection to the DERM at terminal A4 and A5.

Are the DERM terminals damaged or corroded?

Go to Step 11

Go to Step 27

11

Replace the DERM. Refer to Inflatable Restraint Diagnostic Energy Reserve Module .

Has the DERM been replaced?

Go to Step 27

12

Measure the resistance from the DERM electrical harness connector terminal A4 to the inflatable restraint arming sensor electrical harness connector terminal B.

Is the resistance less than the specified value?

5 ohms

Go Step 18

Go to Step 13

13

Disconnect the inflatable restraint arming sensor jumper harness electrical connector C110.

Is the connector damaged or corroded?

--

Go to Step 14

Go to Step 15

14

Repair the inflatable restraint arming sensor jumper harness electrical connector C110.

Has the connector been repaired?

--

Go to Step 27

--

15

Measure the resistance of circuit 236 from the DERM electrical harness connector terminal A4 to the inflatable restraint arming sensor jumper harness electrical connector C110 terminal B.

Is the resistance less than the value specified?

5 ohms

Go to Step 16

Go to Step 17

16

Repair the open in circuit 236 in the inflatable restraint arming sensor jumper harness.

Has the open circuit been repaired?

--

Go to Step 27

--

17

Repair the open in circuit 236 in the SIR wiring harness.

Has the open circuit been repaired?

--

Go to Step 27

--

18

Measure the resistance circuit 1400 from the DERM electrical harness connector terminal A5 to the inflatable restraint arming sensor electrical harness connector terminal C.

Is the resistance less than the value specified?

5 ohms

Go to Step 24

Go to Step 19

19

Disconnect the inflatable restraint arming sensor jumper harness electrical connector C110.

Is the connector terminal C damaged or corroded?

--

Go to Step 20

Go to Step 21

20

Repair the inflatable restraint arming sensor jumper harness electrical connector C110.

Has the connector been repaired?

--

Go to Step 27

--

21

Measure the resistance of circuit 1400 from the DERM electrical harness connector terminal A5 to the inflatable restraint arming sensor jumper harness electrical connector terminal A5 to the inflatable restraint arming sensor jumper harness electrical connector C110 terminal C.

Is the resistance less than the value specified?

5 ohms

Go to Step 22

Go to Step 23

22

Repair the high resistance in circuit 1400 in the inflatable restraint arming sensor jumper harness.

Has the high resistance been repaired?

--

Go to Step 27

--

23

Repair the high resistance in circuit 1400 in the SIR wiring harness.

Has the high resistance been repaired?

--

Go to Step 27

--

24

  1. Turn ON the ignition switch.
  2. Measure the voltage on the DERM electrical harness connector from terminal A5 to terminal A12 (ground).

Is the voltage less than the value specified?

1 V

Go to Step 26

Go to Step 25

25

  1. Turn off the ignition switch.
  2. Repair the short from circuit 1400 to B+.

Has the short circuit been repaired?

--

Go to Step 27

--

26

  1. Turn off the ignition switch.
  2. Replace the inflatable restraint arming sensor. Refer to Inflatable Restraint Arming Sensor .

Has the inflatable restraint arming sensor been replaced?

--

Go to Integrity Check

--

27

  1. Reconnect all the SIR system components.
  2. Ensure that the components are properly mounted.

Have all the SIR system components been reconnected and properly mounted?

--

Go to Step 28

--

28

Clear the SIR Diagnostic Trouble Codes.

Have the SIR Diagnostic Trouble Codes been cleared?

--

Go to SIR Diagnostic System Check

--