GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Cadillac 🢒 2009 🢒 SLS 🢒 Safety and Security 🢒 Supplemental Inflatable Restraints 🢒 DTC B0019 or B0020

Circuit Description

Passenger frontal deployment loop is composed of the following components:

    • A dual stage inflatable restraint I/P module
    • I/P Module - Stage 1 and 2 - High Control
    • I/P Module - Stage 1 and 2 - Low Control

There are 2 shorting bars in the I/P module connector. They will short together both I/P module stage 1 high circuit and I/P module stage 1 low circuit and both I/P module stage 2 high circuit and I/P module stage 2 low circuit when the connector is disconnected. This will help to prevent unwanted deployment of the inflator module during servicing. During a frontal crash of sufficient force the inflatable restraint sensing and diagnostic module (SDM) will allow current to flow through the deployment loop in order to deploy the steering wheel module. The SDM performs continuous diagnostic tests on the deployment loops to check for proper circuit continuity and for shorts to ground or voltage. Any DTC detected will be stored in the memory.

DTC Descriptors
    • DTC B0019 Passenger Frontal Deployment Loop Stage 1
    • DTC B0020 Passenger Frontal Deployment Loop Stage 2

The vehicle has DTCs including the DTC symptoms. Refer to DTC Symptom Description for DTC information.

DTC Symptom

DTC Symptom Descriptor

01

Short to battery

02

Short to ground

04

Open circuit

0D

Resistance above threshold

0E

Resistance below threshold

Conditions for Running the DTC

Ignition voltage is within normal operating range.

Conditions Setting the DTC

B0019 01 Stage 1 or B0020 01 Stage 2

The I/P module high and/or low circuit is short to voltage for 120 milliseconds.

B0019 02 Stage 1 or B0020 02 Stage 2

The I/P module high and/or low circuit is short to ground for 120 milliseconds.

B0019 04 Stage 1 or B0020 04 Stage 2

The I/P module high and/or low circuit is open for 120 milliseconds.

B0019 0D Stage 1 or B0020 0D Stage 2

The I/P module deployment loop resistance is more than 5.1 ohms for 120 milliseconds.

B0019 0E Stage 1 or B0020 0E Stage 2

The I/P module deployment loop resistance is less than 1.3 ohms for 120 milliseconds.

Action Taken When the DTC Sets

The SDM commands the AIR BAG indicator ON via GMLAN serial data communications.

Conditions for Clearing the MIL/DTC
    • When conditions for the DTC to set no longer exist, use CLEAR DTC function of the scan tool to clear the DTC.
    • After 255 consecutive warm-up cycles without failure, the DTC will be cleared.

Diagnostic Aids

The following may be the possible causes for the fault:

    • I/P Module - stage 1 and stage 2 - High and low control short circuit.
    • I/P Module - stage 1 and stage 2 - High or low control open circuit or high resistance.
    • I/P Module - stage 1 and stage 2 - High or low control is short to ground or voltage.
    • I/P module connector
    • The SDM harness connector
    • I/P module fault
    • The SDM module fault

Thoroughly inspect the wiring and connectors. Failure to do so may result in error of diagnosis and the trouble may occur again even when you replace the parts. If there is intermittent conditions, refer to Testing for Intermittent Conditions and Poor Connections .

Test Description

The following numbers are corresponding to the steps in the diagnostic table.

  1. Test if the trouble is caused by instrumental panel module.

    2.

  2. If DTC B0019 01 or B0020 01 is set, test if the I/P module - stage 1 and stage 2 - high or low control is short to battery voltage. If DTC B0019 02 or B0020 02 is set, test if the I/P module - stage 1 and stage 2 - high or low control is short to ground. If DTC B0019 04, 0D, 0E or B0020 04, 0D, 0E is set, test if the I/P module - stage 1 and stage 2 - high or low control is open or high or low in resistance.

Step

Action

Yes

No

Schematic Reference: SIR Schematics

Connector End View Reference: SIR Connector End Views

1

Have you conducted Diagnostic System Check - Vehicle?

Go to Step 2

Go to Diagnostic System Check - Vehicle

2
  1. Turn the ignition switch to OFF position.
  2. Disconnect the I/P module inline connector. Refer to Inflatable Restraint Instrument Panel Module Replacement .
  3. Check the I/P module inline connector to see if there is damage or corrosion that may result in the fault. Refer to Testing for Intermittent Conditions and Poor Connections .

Is there damage or corrosion in the connectors?

Go to Step 3

Go to Step 4

3
  1. If the I/P module inline connector is damaged, replace the I/P module. Refer to Inflatable Restraint Instrument Panel Module Replacement .
  2. If the I/P module connector harness is damaged, replace the harness. Refer to Connector Repairs

Is the trouble corrected?

Go to Step 9

--

4

  1. Use J 38715-80 Adaptor, connect J 38715-A Airbag Driver/Passenger Load Special Tool to the I/P module harness connector. Use steering column base and passenger inflator connector.
  2. Engine off, ignition on.

    3. Important: J-45289 CANdi Module must be used together with the scan tool.

  3. Install the scan tool in order to display the SIR DTCs.

Does the scan tool indicate DTC B0019 or B0020 as current trouble code?

Go to Step 5

Go to Step 7

5
  1. Turn the ignition switch to OFF position.
  2. Disconnect and remove J 38715-A and the adaptor.
  3. Disconnect the SIR system sensing and diagnostic module (SDM) connector. Refer to Control Module References for replacement, setup, and programming.
  4. Check if there is damage or corrosion to the SDM connector, which may result in trouble in I/P module stage 1 or stage 2 loop high and/or low control circuits. Refer to Testing for Intermittent Conditions and Poor Connections .

Do you find and correct the condition?

Go to Step 9

Go to Step 6

6

    • If DTC B0019 01 or B0020 01 is set, test if the I/P module - stage 1 and stage 2 - high or low control is short to battery voltage.
    • If DTC B0019 02 or B0020 02 is set, test if the I/P module - stage 1 and stage 2 - high or low control is short to ground.
    • If DTC B0019 04, 0D, 0E or B0020 04, 0D, 0E is set, test if the I/P module - stage 1 and stage 2 - high or low control is open or high or low in resistance.
    • Refer to Circuit Testing and Wiring Repairs for all the above situations.

Do you find and correct the condition?

Go to Step 9

Go to Step 8

7
  1. Turn the ignition switch to OFF position.
  2. Replace the instrument panel module. Refer to Inflatable Restraint Instrument Panel Module Replacement

Have you finished the replacement?

Go to Step 9

--

8
  1. Turn the ignition switch to OFF position.
  2. Replace the SDM module. Refer to Control Module References for replacement, setup, and programming.

Have you finished the replacement?

Go to Step 9

--

9
  1. Connect all SIR components.
  2. Engine off, ignition on.
  3. Clear away all DTCs with scan tool.
  4. Operate the vehicle under conditions when DTC runs as specified in supporting documents.

Does the DTC set gain?

Go to Step 2

System OK