GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Chevrolet 🢒 2005 🢒 SSR 🢒 Restraints 🢒 SIR 🢒 DTC B0091

Circuit Description

The inflatable restraint instrument panel (I/P) module disable switch circuit consists of an I/P module disable switch, I/P module disable switch indicator, I/P module disable switch signal circuit, and I/P module suppression indicator control circuit. When the ignition is turned ON, the inflatable restraint sensing and diagnostic module (SDM) performs tests to diagnose critical malfunctions within itself. The SDM monitors the voltage levels at the I/P module disable switch signal and the I/P module suppression indicator control circuits of the SDM to determine the position of the I/P module disable switch. If a malfunction is detected, a DTC will be stored.

DTC Descriptor

This diagnostic procedure supports the following DTC:

DTC B0091 Active Switch: Wrong State

Conditions for Running the DTC

Ignition 1 voltage is within the normal operating voltage range.

Conditions for Setting the DTC

The voltage at I/P module disable switch signal is low with the I/P module disable switch indicator ON and the voltage at I/P module suppression indicator control is high for 500 milliseconds.

Action Taken When the DTC Sets
    • The I/P module disable switch is defaulted to a calibrated state.
    • The SDM commands ON the AIR BAG indicator via class 2 serial data.
    • The SDM toggles the I/P module disable switch AIR BAG indicator ON and OFF every 5 seconds.

Conditions for Clearing the DTC
    • The condition responsible for setting the DTC no longer exists.
    • You issue a scan tool CLEAR DTCs 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 between the I/P module disable switch signal and the I/P module suppression indicator control circuits. Refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems.

Test Description

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

  1. This step observes the state of the I/P module disable switch, normal state being ON.

    2.

  2. This step tests for a malfunctioning I/P module disable switch.

    3.

  3. This step tests for a malfunctioning SDM.

    4.

  4. This step tests for a short in the I/P module disable switch signal circuit.

    5.

  5. This step tests for a short in the I/P module suppression indicator control circuit.

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 in Vehicle DTC Information

2
  1. Turn OFF the ignition.
  2. Disconnect the instrument panel (I/P) module disable switch. Refer to Inflatable Restraint Instrument Panel Module Disable Switch Replacement .
  3. Inspect the I/P module disable switch connector for corrosion or damage. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 11

Go to Step 3

3

  1. Reconnect the I/P module disable switch connector.
  2. Turn the I/P module disable switch to the OFF position.
  3. Turn ON the ignition, with the engine OFF.
  4. With a scan tool, observe the I/P module disable switch (active switch) data parameter in the inflatable restraint sensing and diagnostic module (SDM) inputs list.

Does the scan tool indicate that the I/P module disable switch (active switch) is DISABLED?

Go to Step 4

Go to Step 5

4

  1. Turn the I/P module disable switch to the ON position.
  2. With a scan tool, observe the I/P module disable switch (active switch) data parameter.

Does the I/P module disable switch (active switch) data parameter change state?

Go to Diagnostic Aids

Go to Step 5

5

  1. Turn OFF the ignition.
  2. Disconnect the I/P module disable switch. Refer to Inflatable Restraint Instrument Panel Module Disable Switch Replacement .
  3. Turn ON the ignition, with the engine OFF.
  4. With a scan tool, observe the I/P module disable switch (active switch) data parameter.

Does the scan tool indicate that the I/P module disable switch (active switch) is DISABLED?

Go to Step 10

Go to Step 6

6

Test the I/P module disable switch signal circuit for a short. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 11

Go to Step 7

7

Test the I/P module suppression indicator control circuit for a short. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 11

Go to Step 8

8
  1. Turn OFF the ignition.
  2. Disconnect the SDM connector. Refer to Inflatable Restraint Sensing and Diagnostic Module Replacement .
  3. Inspect the SDM connector for corrosion or damage. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 11

Go to Step 9

9

Replace the SDM. Refer to Control Module References in Computer/Integrating Systems for replacement, setup, and programming.

Did you complete the replacement?

Go to Step 11

--

10

Replace the I/P module disable switch. Refer to Inflatable Restraint Instrument Panel Module Disable Switch Replacement .

Did you complete the replacement?

Go to Step 11

--

11
  1. Reconnect all SIR system components.
  2. Verify that all components, connectors and connector position assurances (CPAs) are properly mounted.
  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