GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Cadillac 🢒 2000 🢒 Catera 🢒 Restraints 🢒 SIR 🢒 DTC 33 Pass. Air Bag Deploy. Loop Resistance High

Object Number: 601068 Size: SF
SIR Components
Power, Ground, Serial Data, Indicator and Front Inflatable Restraint Modules
SIR Handling 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 that 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 passenger frontal high and passenger frontal low circuits
    • Uses the measured voltage to calculate the resistance of the passenger 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 the 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 passenger frontal air bag deployment loop.

Conditions for Setting the DTC

The calculated resistance of the passenger frontal air bag deployment loop is above 2.3 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 IP module 2-way connector.
    • The SDM wiring harness connector.
    • The wire to terminal connections in the passenger frontal high circuit.
    • The wire to terminal connections in the passenger 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 IP module 2-way connector.

    2.

  2. This step checks the SDM wiring harness connector.

    3.

  3. This step checks for an open or a high resistance in the passenger frontal high circuit.

    4.

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

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. Disconnect the inflatable restraint IP module 2-way connector. Refer to Inflatable Restraint Instrument Panel Module Replacement .
  4. Inspect the male and female sides of the inline 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 either the male or female sides of the inline connector exhibit signs or corrosion, terminal damage, or poor connections?

--

Go to Step 3

Go to Step 4

3
  1. If the female side of the inline connector is damaged, the inflatable restraint IP module must be replaced.
  2. If the male side of the inline connector is damaged, replace the male side of the connector. Refer to Connector Repairs in Wiring Systems.

Did you complete the repair?

--

Go to Step 14

--

4
  1. Reconnect the inflatable restraint IP module 2-way connector.
  2. Verify that the connector position assurance (CPA) is properly installed.
  3. Turn ON the ignition, with the engine OFF.
  4. Use the scan tool to request the SIR DTC display.

Does the scan tool indicate that this DTC is current?

--

Go to Step 5

Go to Diagnostic Aids

5
  1. Turn OFF the ignition.
  2. Remove the ignition key.
  3. Use the J 38715-55 adapter to connect the J 38715-A SIR Driver/Passenger Load Tool PASSENGER INFLATOR connector to the inflatable restraint IP module wiring harness connector.
  4. Turn ON the ignition, with the engine OFF.
  5. Use the scan tool to request the SIR data list display.
  6. Read the passenger frontal air bag deployment loop resistance PASSENGER AIR BAG RES.

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

2.3 ohms

Go to Step 7

Go to Step 6

6
  1. Turn OFF the ignition.
  2. Remove the ignition key.
  3. Replace the inflatable restraint IP module. Refer to Inflatable Restraint Instrument Panel Module Replacement .

Did you complete the replacement?

--

Go to Step 14

--

7

  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. Refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems:
    6. • Corrosion
    • Damaged terminals
    • Poor connections/terminal tension

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

--

Go to Step 8

Go to Step 9

8

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

Did you complete the repair?

--

Go to Step 14

--

9

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

Does the resistance measure less than the specified value?

0.5 ohms

Go to Step 11

Go to Step 10

10

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

Did you complete the repair?

--

Go to Step 14

--

11

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

Does the resistance measure less than the specified value?

0.5 ohms

Go to Step 13

Go to Step 12

12

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

Did you complete the repair?

--

Go to Step 14

--

13

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

Did you complete the repair?

--

Go to Step 14

--

14
  1. Reconnect all SIR components.
  2. Verify that all components and connectors 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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