GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 GMC_Truck 🢒 2004 🢒 GMC C Sierra - 2WD 🢒 Restraints 🢒 SIR 🢒 DTC B0091

Circuit Description

The inflatable restraint IP module disable switch circuit consists of an IP module disable switch, IP module disable switch indicator, IP module disable switch signal circuit, and IP 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 IP module disable switch signal and the IP module suppression indicator control circuits of the SDM to determine the position of the IP module disable switch. If a malfunction is detected, a DTC will be stored.

Conditions for Running the DTC

Ignition 1 voltage is within the normal operating voltage range.

Conditions for Setting the DTC

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

Action Taken When the DTC Sets
    • The IP module disable switch is defaulted to a calibrated state.
    • The SDM commands the AIR BAG indicator ON via Class 2 serial data.
    • The SDM toggles the IP 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 IP module disable switch signal and the IP 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. Observes the state of the IP module disable switch, normal state being ON.

    2.

  2. Tests for a malfunctioning IP module disable switch.

    3.

  3. Tests for a malfunctioning SDM.

    4.

  4. Tests for a short in the IP module disable switch signal circuit.

    5.

  5. Tests for a short in the IP 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 - SIR?

Go to Step 2

Go to Diagnostic System Check - SIR

2
  1. Turn OFF the ignition.
  2. Disconnect the IP module disable switch. Refer to Inflatable Restraint Instrument Panel Module Disable Switch Replacement .
  3. Inspect the IP 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 IP module disable switch connector.
  2. Turn the IP module disable switch to the OFF position.
  3. Turn ON the ignition, with the engine OFF.
  4. With a scan tool, observe the IP module disable switch (active switch) data parameter in the SDM inputs list.

Does the scan tool indicate that the IP module disable switch (active switch) is DISABLED?

Go to Step 4

Go to Step 5

4

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

Does the IP 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 IP 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 IP module disable switch (active switch) data parameter.

Does the scan tool indicate that the IP module disable switch (active switch) is DISABLED?

Go to Step 10

Go to Step 6

6

Test the IP 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 IP 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 Inflatable Restraint Sensing and Diagnostic Module Replacement .

Did you complete the replacement?

Go to Step 11

--

10

Replace the IP 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 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