GM Service Manual Online
For 1990-2009 cars only

Circuit Description

The passenger roof rail deployment loop consists of the following components:

    • An inflatable restraint right roof rail module
    • The roof rail module-right high circuit
    • The roof rail module-right low circuit

The passenger roof rail deployment loop consists of an inflatable restraint roof rail module-right, the roof rail module-right high, and the roof rail module-right low circuits. A shorting bar used within the roof rail module connector which will short together both roof rail module-right high and low circuits when the connector is disconnected. This will help to prevent unwanted deployment of the inflator module during servicing. During a side or 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 roof side rail module. The SDM performs continuous diagnostic tests on the deployment loops to check for proper circuit continuity and for shorts to ground or voltage. If a malfunction is detected, a DTC will be stored in memory.

DTC Descriptor

This diagnostic procedure supports the following DTC:

DTC B0023 Right Roof Rail Deployment Loop

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 the normal operating voltage range.

Conditions for Setting the DTC

B0023 01

The roof rail module-right high and/or low circuit is short to voltage for 120 milliseconds.

B0023 02

The roof rail module-right high and/or low circuit is short to ground for 120 milliseconds.

B0023 04

The roof rail module-right high and/or low circuit is open for 120 milliseconds.

B0023 0D

The steering wheel module deployment loop resistance is more than 3.9 ohms for 120 milliseconds.

B0023 0E

The steering wheel module deployment loop resistance is less than 1.1 ohms for 120 milliseconds.

Action Taken When the DTC Sets

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

Conditions for Clearing the MIL/DTC

    • The condition responsible for setting the DTC no longer exists and the scan tool Clear DTCs function is used.
    • A history DTC will clear once 255 malfunction-free ignition cycles have occurred.

Diagnostic Aids

The following are possible causes of the malfunction:

    • A short between the roof rail module-right high and low circuits
    • An open or a high resistance in the roof rail module-right high or low circuits
    • A short to ground or a short to voltage in the roof rail module-right high or low circuits
    • The roof rail module-right connector
    • The SDM connector
    • A malfunctioning roof rail module-right
    • A malfunctioning SDM

Thoroughly inspect the wiring and the connectors. An incomplete inspection of the wiring and the connectors may result in a misdiagnosis, causing a part replacement with the reappearance of the malfunction. If an intermittent malfunction exists, refer to Testing for Intermittent Conditions and Poor Connections .

Test Description

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

  1. This step tests to see if the malfunction is caused by the roof rail module-right.

  2. This step tests to see what DTCs are present. If DTC B0023 01 is present, test the roof rail module-right for a short to battery voltage on the high and low circuits. If DTC B0023 02 is present, test the roof rail module-right for a short to ground on the high and low circuits. If DTC B0023 04, 0D, 0E is present, test the roof rail module-right test the high and low circuits for an open circuit and for high or low resistance.

Step

Action

Yes

No

Schematic Reference: SIR Schematics

Connector End View Reference: SIR Connector End Views

1

Did you perform the Diagnostic System Check - Vehicle?

Go to Step 2

Go to Diagnostic System Check - Vehicle

2

  1. Turn OFF the ignition.
  2. Disconnect roof rail module-right in-line connector. Refer to Inflatable Restraint Roof Side Rail Module Replacement - Front .
  3. Inspect the component and harness sides of the in-line connector for the roof rail module-right for damage or corrosion that may cause the malfunction. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs .

Does the connector exhibit any signs of damage or corrosion?

Go to Step 3

Go to Step 4

3

  1. If the connector for the roof rail module-right is damaged, the roof rail module-right must be replaced. Refer to Inflatable Restraint Roof Side Rail Module Replacement - Front .
  2. If the wiring harness side of the roof rail module-right connector is damaged, replace the harness side of the connector. Refer to Connector Repairs in Wiring Systems.

Did you complete the repair?

Go to Step 9

--

4

  1. Use the J 38715-30A adapter to connect the J 38715-A SIR Driver/Passenger Load Tool to the harness side of the roof rail module-right connector. Use PASSENGER INFLATOR connector.
  2. Turn ON the ignition, with the engine OFF.
  3. Important: The EL-39021-460 CANdi module must be used with the scan tool.

  4. Install a scan tool, and request the SIR DTC display.

Does the scan tool indicate that DTC B0023 is current?

Go to Step 5

Go to Step 7

5

  1. Turn OFF the ignition.
  2. Disconnect and remove both the J 38715-A and adapter.
  3. Disconnect the inflatable restraint sensing and diagnostic module (SDM) connector. Refer to Control Module References for replacement, setup, and programming.
  4. Inspect the SDM connector for damage or corrosion that may cause a malfunction in the roof rail module-right high and/or low circuits. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs .

Did you find and correct the condition?

Go to Step 9

Go to Step 6

6

  1. If DTC B0023 01 is present, test the roof rail module-right for a short to battery voltage on the high and low circuits.
  2. If DTC B0023 02 is present, test the roof rail module-right for a short to ground on the high and low circuits.
  3. If DTC B0023 04, 0D, 0E is present, test the roof rail module-right, test the high and low circuits for an open circuit and for high or low resistance.
  4. For all the above conditions, refer to Circuit Testing and Wiring Repairs .

Did you find and correct the condition?

Go to Step 9

Go to Step 8

7

  1. Turn OFF the ignition.
  2. Replace the roof rail module-right. Refer to Inflatable Restraint Roof Side Rail Module Replacement - Front .

Did you complete the replacement?

Go to Step 9

--

8

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

Did you complete the replacement?

Go to Step 9

--

9

  1. Connect all SIR components.
  2. Turn ON the ignition, with the engine OFF.
  3. Use the scan tool in order to clear the DTCs.
  4. Operate the vehicle within the Conditions for Running the DTC as specified in the supporting text.

Does the DTC reset?

Go to Step 2

System OK