GM Service Manual Online
For 1990-2009 cars only

Diagnostic Instructions

    • Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
    • Review Strategy Based Diagnosis for an overview of the diagnostic approach.
    •  Diagnostic Procedure Instructions provides an overview of each diagnostic category.

DTC Descriptor

DTC B0090: Active Switch Voltage Out of Range

Circuit/System 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.

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 and I/P module suppression indicator control is low or high with the I/P module disable switch indicator OFF for 500 milliseconds.

Action Taken When the DTC Sets

    • The I/P module disable switch is defaulted to a calibration state.
    • The SDM commands the AIR BAG indicator ON via class 2 serial data.

Conditions for Clearing the DTC

    • The condition responsible for setting the DTC no longer exists.
    • The scan tool CLEAR DTC command has been issued.
    •  A history DTC will clear once 255 malfunction-free ignition cycles have occurred.

Diagnostic Aids

A short between the I/P module disable switch signal and I/P module suppression indicator control circuits can cause an intermittent condition.

Reference Information

Schematic Reference

SIR Schematics

Connector End View Reference

SIR Connector End Views

Electrical Information Reference

    •  Circuit Testing
    •  Connector Repairs
    •  Testing for Intermittent Conditions and Poor Connections
    •  Wiring Repairs

Circuit/System Testing

  1. Turn OFF the ignition. Turn the I/P module disable switch to the ON position. Connect the scan tool. Turn ON the ignition, with the engine OFF. The I/P module disable switch ON indicator should illuminate. Scan tool should display ENABLED.
  2. If the indicator does not illuminate, test the I/P module disable switch power and ground circuits for proper operation. If any of the above conditions are found, make appropriate repair.
    Replace the I/P module disable switch.
  3. Turn the I/P module disable switch on and off and verify that the active switch data parameter toggles between Enabled/Disabled.
  4. Test the I/P module disable signal and suppression indicator control circuits for a short to voltage, short to ground or open/high resistance. If any of the above conditions are found, make the appropriate repair.
    Replace I/P module disable switch.
  5. Reconnect all components, with ignition ON use the scan tool to clear DTC. Recheck for DTC. If DTC B0090 resets, replace the SDM.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

    •  Inflatable Restraint Instrument Panel Module Disable Switch Replacement
    •  SIR/SRS Wiring Repairs
    •  Control Module References for SDM replacement, setup, and programming