GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Cadillac 🢒 2000 🢒 DeVille 🢒 DTC 🢒 DTC B0024 LF/Driver Frontal Deployment Loop (Single Stage or Stage 1) Short to Ground/Voltage Out of Range

Object Number: 465543 Size: MF
SIR Components
SDM, Front and Rear Side Inflator Modules with Option AW9
SIR Handling Caution
Handling ESD Sensitive Parts Notice
SIR Schematic Icons

Circuit Description

When you first turn ON the ignition, the inflatable restraint sensing and diagnostic module (SDM) performs tests to diagnose critical malfunctions within itself. Then the SDM performs the following continuous diagnostic tests on the deployment loops:

    • Deployment loop voltage out of range test
    • Deployment loop resistance measurement test

If the voltage out of range test detects a short to voltage condition, the resistance measurement test for that deployment loop will not be performed.

Conditions for Running the DTC

Deployment loop voltage out of range test - The ignition 1 voltage is within the normal operating voltage range.

Deployment loop resistance measurement test:

    • The ignition 1 voltage is within the normal operating voltage range.
    • The driver frontal deployment loop is not shorted to voltage.

Conditions for Setting the DTC
    • Deployment loop voltage out of range test - The driver frontal high terminal is greater than 6 volts for 500 milliseconds.
    • Deployment loop resistance measurement test - The driver frontal high terminal is less than 2.4 volts and the driver frontal deployment loop resistance is less than 6 ohms for 500 milliseconds.

Action Taken When the DTC Sets

The SDM commands ON the AIR BAG warning lamp via Class 2 serial data.

Conditions for Clearing the DTC
    • The driver frontal high terminal is less than or equal to 6 volts for 500 milliseconds.
    • The driver frontal high terminal is greater than or equal to 2.4 volts and the driver frontal deployment loop resistance is less than 6 ohms for 500 milliseconds.
    • 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:

    • A short to ground or to voltage on either of the two sides of the deployment loop circuit can cause an intermittent condition.
    • Inspect the driver frontal high and the driver frontal low circuits carefully for cutting or chafing or any type of wire damage.
    • Wiring pigtail damage requires replacement of the inflatable restraint steering wheel module coil.

If any of the above conditions are found refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems.

Test Description

The number(s) below refer to the step number(s) on the diagnostic table.

  1. This step checks the driver inflator module in-line connector below the steering wheel restraint module coil.

    2.

  2. This step test for the proper operation of the inflatable restraint steering wheel module coil and/or the inflatable restraint steering wheel inflator module.

    3.

  3. This step checks to see if there is a short to ground in the driver frontal high deployment circuit.

    4.

  4. This step checks to see if there is a short to ground in the driver frontal low deployment circuit.

    5.

  5. This step checks to see if there is a short to voltage in the driver frontal high deployment circuit.

  6. This step determines if there is a short to voltage in the driver frontal low deployment circuit, or if there is a malfunctioning SDM.

    7.

  7. This step clears all of the SIR DTCs.

Step

Action

Value(s)

Yes

No

1

Did you perform the Diagnostic System Check?

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Go to Step 2

Go to Diagnostic System Check - SIR

2

  1. Turn OFF the ignition.
  2. Disconnect the in-line connector that connects the steering wheel restraint module coil to the vehicle wiring harness.
  3. Inspect both of the wiring harness connectors for the following conditions:
    4. • Corrosion
    • Terminal damaged
    • Poor connections/terminal tension
  4. If any of the above conditions are found refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems.

Do the connectors exhibit any signs of corrosion, terminal damaged, or poor connections?

--

Go to Step 3

Go to Step 4

3
  1. Replace the wiring harness side of the in-line connector. Refer to Connector Repairs in Wiring Systems.
  2. If the steering wheel restraint module coil exhibits any of the above conditions, the module must be replace. Refer to Inflatable Restraint Steering Wheel Module Coil Replacement .

Did you complete the replacement?

--

Go to Step 18

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4
  1. Reconnect the in-line 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 SIR DTCs displayed.

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. Disconnect the in-line connector below the steering wheel restraint module coil.
  3. Install the J 38715-A SIR Load Tool to the vehicle wiring harness in-line connector. Use the appropriate wiring harness connector adaptors where necessary.
  4. Turn ON the ignition, with the engine OFF.
  5. Use the scan tool to request SIR DTCs displayed.

Does the scan tool indicate that this DTC is current?

--

Go to Step 9

Go to Step 6

6

  1. Turn OFF the ignition.
  2. Remove the inflatable restraint steering wheel inflator module. Refer to Inflatable Restraint Steering Wheel Module Replacement .
  3. Disconnect the J 38715-A from the in-line connector.
  4. Reconnect the in-line connector back together.
  5. Connect the J 38715-A to the upper inflatable restraint steering wheel module coil connector on the steering column.
  6. Turn ON the ignition, with the engine OFF.
  7. Use the scan tool to request SIR DTCs displayed.

Does the scan tool indicate that this DTC is current?

--

Go to Step 8

Go to Step 7

7
  1. Turn OFF the ignition.
  2. Replace the inflatable restraint steering wheel inflator module. Refer to Inflatable Restraint Steering Wheel Module Replacement .

Did you complete the replacement?

--

Go to Step 18

--

8
  1. Turn OFF the ignition.
  2. 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 18

--

9

  1. Turn OFF the ignition.
  2. Disconnect the inflatable restraint sensing and diagnostic module (SDM) wiring harness connector. Refer to Inflatable Restraint Sensing and Diagnostic Module Replacement .
  3. Disconnect the J 38715-A .
  4. Use the J 39200 DMM and measure the resistance between the SDM wiring harness connector driver frontal high circuit and a known good ground.

Does the resistance measure less than the specified value?

OL

Go to Step 10

Go to Step 11

10

Locate and repair a short to ground in the driver frontal high circuit. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you complete the repair?

--

Go to Step 18

--

11

Use the J 39200 and measure the resistance between the SDM wiring harness connector driver frontal low circuit and a known good ground.

Does the resistance measure less than the specified value?

OL

Go to Step 12

Go to Step 13

12

Locate and repair a short to ground in the driver frontal low circuit. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you complete the repair?

--

Go to Step 18

--

13

  1. Turn ON the ignition, with the engine OFF.
  2. Use the J 39200 and measure the voltage between the SDM wiring harness connector driver frontal high circuit and a known good ground.

Does the voltage measured less than the specified value?

1 V

Go to Step 15

Go to Step 14

14

Locate and repair a short to voltage in the driver frontal high circuit. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you complete the repair?

--

Go to Step 18

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15

Use the J 39200 and measure the voltage between the SDM wiring harness connector driver frontal low circuit and a known good ground.

Does the voltage measured less than the specified value?

1 V

Go to Step 17

Go to Step 16

16

Locate and repair a short to voltage in the driver frontal low circuit. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you complete the repair?

--

Go to Step 18

--

17

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

Did you complete the replacement?

--

Go to Step 18

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18

  1. Reconnect all of the SIR components.
  2. Verify that all of the components, connectors and CPAs are properly mounted.
  3. Turn ON the ignition, with the engine OFF.
  4. Use the scan tool in order to Clear the DTCs.
  5. Operate the vehicle within the Conditions for Running the DTC as specified in the supporting text.

Did you complete the action?

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Go to Diagnostic System Check - SIR

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