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For 1990-2009 cars only
Makes 🢒 Chevrolet 🢒 1999 🢒 Corvette 🢒 Restraints 🢒 SIR 🢒 DTC B0024 LF/Driver Frontal Deployment Loop (Single Stage or Stage 1) Short to Ground/Voltage Out of Range

Object Number: 391012 Size: SF
SIR Components
SIR Schematics
SIR Caution
Handling ESD Sensitive Parts Notice

Circuit Description

When you first turn the ignition switch to the ON position, 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 Setting the DTC
    • Deployment loop voltage out of range test.
       - Ignition 1 voltage is within the normal operating voltage range.
       - Driver frontal high terminal A6 is more than 6 volts for 300 milliseconds.
    • Deployment loop resistance measurement test.
       - Ignition 1 voltage is within the normal operating voltage range.
       - Driver frontal deployment loop is not shorted to voltage.
       - Driver frontal high terminal A6 is less than 2 volts AND driver frontal deployment loop resistance is less than 6 ohms for 300 milliseconds.

The driver frontal deployment loop consists of the following components:

    • Inflatable restraint steering wheel module.
    • Inflatable restraint steering wheel module coil.
    • Harness wiring of CKT 347.
    • Harness wiring of CKT 348.
    • Connector terminal contact.

Action Taken When the DTC Sets
    • The SDM sets a DTC B0024
    • The SDM commands ON the AIR BAG warning lamp via Class 2 serial data.

Conditions for Clearing the DTC
    • Current DTC
       - Deployment loop voltage out of range test-Driver frontal high terminal A6 is no more than 6 volts.
       - Deployment loop resistance measurement test-Driver frontal high terminal A6 is more than 2 volts AND driver frontal deployment loop resistance is less than 6 ohms for 300 milliseconds.
    • History DTC
       - You issue a scan tool CLEAR CODES command.
       - Once 250 malfunction free ignition cycles have occurred.

Diagnostic Aids

A short to B+ or short to Ground in the inflatable restraint steering wheel module circuit can cause an intermittent condition. Inspect CKT 347 and CKT 348 carefully for cutting or chafing. Wiring pigtail damage requires replacement of the inflatable restraint steering wheel module coil.

Test Description

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

  1. This step checks the inline connector C211.

    2.

  2. This step determines if the inflatable restraint steering wheel module coil or the inflatable restraint steering wheel module is defective.

    3.

  3. This step checks to see if there is a short to ground in CKT 347.

    4.

  4. This step checks to see if there is a short to ground in CKT 348.

    5.

  5. This step checks to see if there is a short to B+ in CKT 347.

    6.

  6. This step determines if there is a short to B+ in CKT 348 or if there is a malfunctioning SDM.

    7.

  7. This step clears all SIR DTCs and also DTC U1088.

DTC B0024 Driver Frontal Deployment Loop Voltage Out Of Range

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. Disconnect inline connector C211.
  3. Check the wiring harness side of inline connector C211 for corrosion or damaged terminals.

Is the wiring harness connector OK?

--

Go to Step 4

Go to Step 3

3

Replace the wiring harness side of inline connector C211. Refer to Wiring Repair .

Is the repair complete?

--

Go to Step 18

--

4
  1. Reconnect inline connector C211.
  2. Make sure that the connector position assurance (CPA) is properly installed.
  3. Turn the ignition switch to the ON position.
  4. Use the scan tool to request the SIR DTC display.

Is DTC B0024 current?

--

Go to Step 5

Go to Step 3

5
  1. Turn the ignition switch to the OFF position.
  2. Disconnect inline connectors C211 and C213.
  3. Install the J 38715-A SIR Driver/Passenger Load Tool to the wiring harness side of inline connectors C211 and C213. Use the appropriate wiring harness connector adaptors where necessary.
  4. Turn the ignition switch to the ON position.
  5. Use the scan tool to request the SIR DTC display.

Is DTC B0024 current?

--

Go to Step 9

Go to Step 6

6

  1. Turn the ignition switch to the OFF position.
  2. Remove the inflatable restraint steering wheel module. Refer to Inflatable Restraint Steering Wheel Module Replacement .
  3. Disconnect the J 38715-A from inline connector C211.
  4. Connect inline connector C211 back together.
  5. Connect the J 38715-A to the upper inflatable restraint steering wheel module coil connector on the steering column.
  6. Turn the ignition switch to the ON position.
  7. Use the scan tool to request the SIR DTC display.

Is DTC B0024 current?

--

Go to Step 8

Go to Step 7

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

Is the repair complete?

--

Go to Step 18

--

8
  1. Turn the ignition switch to the OFF position.
  2. Replace the inflatable restraint steering wheel module coil. Refer to Inflatable Restraint Steering Wheel Module Coil Replacement .

Is the repair complete?

--

Go to Step 18

--

9

  1. Turn the ignition switch to the OFF position.
  2. Disconnect the inflatable restraint sensing and diagnostic module (SDM) connector. Refer to Inflatable Restraint Sensing and Diagnostic Module Replacement .
  3. Disconnect the J 38715-A .
  4. Use the J 39200 Digital Multimeter (DMM) to measure the resistance between terminal A6 of the SDM wiring harness connector and a known good ground.

Is the measured resistance less than the specified value?

OL

Go to Step 10

Go to Step 11

10
  1. Locate a short to ground in CKT 347.
  2. Repair the short to ground in CKT 347.

Is the repair complete?

--

Go to Step 18

--

11

Use the DMM to measure the resistance between terminal A7 of the SDM wiring harness connector and a known good ground.

Is the measured resistance less than the specified value?

OL

Go to Step 12

Go to Step 13

12
  1. Locate a short to ground in CKT 348.
  2. Repair the short to ground in CKT 348.

Is the repair complete?

--

Go to Step 18

--

13

  1. Turn the ignition switch to the ON position.
  2. Use the DMM to measure the voltage between terminal A6 of the SDM wiring harness connector and a known good ground.

Is the measured voltage less than the specified value?

1V

Go to Step 15

Go to Step 14

14
  1. Locate a short to B+ in CKT 347.
  2. Repair the short to B+ in CKT 347.

Is the repair complete?

--

Go to Step 18

--

15

Use the DMM to measure the voltage between terminal A7 of the SDM wiring harness connector and a known good ground.

Is the measured voltage less than the specified value?

1V

Go to Step 17

Go to Step 16

16
  1. Locate a short to B+ in CKT 348.
  2. Repair the short to B+ in CKT 348.

Is the repair complete?

--

Go to Step 18

--

17

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

Is the repair complete?

--

Go to Step 18

--

18

  1. Reconnect all SIR components.
  2. Make sure that all components and connectors are properly mounted.
  3. Turn the ignition switch to the ON position.
  4. Use the scan tool to clear all current and history SIR DTCs.
  5. Also clear DTC U1088 in all modules that communicate with the SDM. Refer to Data Link Communications.

Have all current and history DTCs been cleared?

--

Go to SIR Diagnostic System Check

--