GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Cadillac 🢒 2000 🢒 Catera 🢒 DTC 🢒 DTC 31 Driver Air Bag Deploy. Loop Resistance High

Object Number: 601070 Size: SF
SIR Components
Power, Ground, Serial Data, Indicator and Front Inflatable Restraint Modules
SIR Caution
Handling ESD Sensitive Parts Notice

Circuit Description

When you first turn ON the ignition, the inflatable restraint sensing and diagnostic and seat belt pretensioner module (SDM) performs tests to diagnose critical malfunctions within itself. Then, the SDM proceeds with the RESISTANCE MEASUREMENT test to measure the deployment loop resistances to ensure they are within their respective normal resistance ranges. During one portion of the RESISTANCE MEASUREMENT test, the SDM does the following:

    • Measures the voltage difference between the driver frontal high and the driver frontal low circuits
    • Uses the measured voltage to calculate the resistance of the driver frontal air bag deployment loop

Upon passing these tests, the energy reserve is charged and the firing transistors are tested. The SDM then goes into CONTINUOUS MONITORING mode.

Conditions for Running the DTC

When the ignition voltage is within the normal operating voltage range, the SDM performs the RESISTANCE MEASUREMENT test in order to calculate the resistance of the driver frontal air bag deployment loop.

Conditions for Setting the DTC

The calculated resistance of the driver frontal air bag deployment loop is above 2.9 ohms.

Action Taken When the DTC Sets

The SDM turns ON the AIR BAG warning lamp.

Conditions for Clearing the DTC
    • You can issue a CLEAR CODES command.
    • A history DTC will clear once 255 malfunction free ignition cycles have occurred.

Diagnostic Aids

The following can cause an intermittent condition:

    • The inflatable restraint steering wheel module coil integral connector.
    • The inflatable restraint steering wheel module coil wiring harness connector.
    • The wire to terminal connections in the driver frontal high circuit.
    • The wire to terminal connections in the driver frontal low circuit.
    • Refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems.

Test Description

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

  1. This step checks the inflatable restraint steering wheel module coil integral connector.

    2.

  2. This step checks to see if the inflatable restraint steering wheel module is defective.

    3.

  3. This step checks to see if the inflatable restraint steering wheel module coil is defective.

    4.

  4. This step checks the SDM wiring harness connector.

    5.

  5. This step checks to see if there is an open or a high resistance in the driver frontal high circuit.

    6.

  6. This step determines if there is an open or a high resistance in the driver frontal low circuit or if there is a malfunctioning SDM.

    7.

  7. This step clears all DTCs.

Step

Action

Value(s)

Yes

No

1

Did you perform A Diagnostic System Check - SIR?

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Go to Step 2

Go to Diagnostic System Check - SIR

2

  1. Turn OFF the ignition.
  2. Remove the ignition key.
  3. Remove the inflatable restraint steering wheel module. Refer to Inflatable Restraint Steering Wheel Module Replacement .
  4. Inspect the inflatable restraint steering wheel module coil integral connector for the following conditions. Refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems:
    5. • Corrosion
    • Damaged terminals
    • Poor connections/terminal tension

Does the inflatable restraint steering wheel module coil integral connector exhibit signs of corrosion, terminal damage, or poor connections?

--

Go to Step 3

Go to Step 4

3

Replace the inflatable restraint steering wheel module coil. Refer to Inflatable Restraint Steering Wheel Module Coil Replacement .

Did you complete the replacement?

--

Go to Step 15

--

4

  1. Use the J 38715-30A adaptor to connect the J 38715-A SIR Driver/Passenger Load Tool STEERING COLUMN connector to the inflatable restraint steering wheel module coil integral connector.
  2. Turn ON the ignition, with the engine OFF.
  3. Use the scan tool to request the SIR data list display.
  4. Read the driver frontal air bag deployment loop resistance DRIVER AIR BAG RES.

Does the scan tool indicate that the DRIVER AIR BAG RES. is greater than the specified value?

2.9 ohms

Go to Step 6

Go to Step 5

5
  1. Turn OFF the ignition.
  2. Remove the ignition key.
  3. Replace the inflatable restraint steering wheel module. Refer to Inflatable Restraint Steering Wheel Module Replacement .

Did you complete the replacement?

--

Go to Step 15

--

6

  1. Turn OFF the ignition.
  2. Remove the ignition key.
  3. Remove the J 38715-A .
  4. Disconnect the inflatable restraint steering wheel module coil wiring harness connector. Refer to Inflatable Restraint Steering Wheel Module Coil Replacement .
  5. Use the J 38715-40 adaptor to connect the J 38715-A SIR Driver/Passenger Load Tool BASE OF COLUMN connector to the inflatable restraint steering wheel module coil wiring harness connector.
  6. Turn ON the ignition, with the engine OFF.
  7. Use the scan tool to request the SIR data list display.
  8. Read the driver frontal air bag deployment loop resistance DRIVER AIR BAG RES.

Does the scan tool indicate that the DRIVER AIR BAG RES. is greater than the specified value?

2.9 ohms

Go to Step 8

Go to Step 7

7
  1. Turn OFF the ignition.
  2. Remove the ignition key.
  3. Replace the inflatable restraint steering wheel module coil. Refer to Inflatable Restraint Steering Wheel Module Coil Replacement .

Did you complete the replacement?

--

Go to Step 15

--

8

  1. Turn OFF the ignition.
  2. Remove the ignition key.
  3. Remove the J 38715-A .
  4. Disconnect the inflatable restraint sensing and diagnostic and seat belt pretensioner module (SDM). Refer to Inflatable Restraint Sensing and Diagnostic and Seat Belt Pretensioner Module Replacement .
  5. Inspect the SDM wiring harness connector for the following conditions:
    6. • Corrosion
    • Damaged terminals
    • Poor connections/terminal tension

Does the SDM wiring harness connector exhibit signs of corrosion, terminal damage, or poor connections?

--

Go to Step 9

Go to Step 10

9

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

Did you complete the replacement?

--

Go to Step 15

--

10

  1. Insert the J 42113 SIR Shorting Bar Tool into the SDM wiring harness connector above the driver frontal high and driver frontal low circuits.
  2. Zero the J 39200 Digital Multimeter (DMM).
  3. Use the DMM to measure the resistance of the driver frontal high circuit.

Does the resistance measure less than the specified value?

0.5 ohms

Go to Step 12

Go to Step 11

11

Locate and repair the open or high resistance in the driver frontal high circuit. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you complete the repair?

--

Go to Step 15

--

12

Use the DMM to measure the resistance of the driver frontal low circuit.

Does the resistance measure less than the specified value?

0.5 ohms

Go to Step 14

Go to Step 13

13

Locate and repair the open or high resistance in the driver frontal low circuit. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you complete the repair?

--

Go to Step 15

--

14

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

Did you complete the replacement?

--

Go to Step 15

--

15

  1. Reconnect all SIR components.
  2. Verify that all connectors and components are properly mounted.
  3. Turn ON the ignition, with the engine OFF.
  4. Use the scan tool in order to clear the DTCs.

Did you complete the action?

--

Go to Diagnostic System Check - SIR

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