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 provide an overview of each diagnostic category

Diagnostic Fault Information

Circuit

Short to Ground

Low Resistance

High Resistance

Open

Short to Voltage

IPM - Low Control

B0018

B0016

B0017

B0017

B0018

IPM - High Control

B0018

B0016

B0017

B0017

B0018

DTC Descriptors

DTC B0016: Passenger Frontal Deployment Loop Resistance Low

DTC B0017:  Passenger Frontal Deployment Loop Open

DTC B0018: Passenger Frontal Deployment Loop Voltage Out of Range

Circuit Description

The inflatable restraint instrument panel module (IPM) deployment loop consists of an IPM, IPM high control, and IPM low control circuits. A shorting bar is used on the IPM connector which will short together the IPM high and IPM low control circuits when the connector is disconnected. This will help to prevent unwanted deployment of the inflator module during servicing. When the ignition is turned ON, the inflatable restraint sensing and diagnostic module (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.

Conditions for Running the DTC

Ignition 1 voltage is within the normal operating voltage range.

Conditions for Setting the DTC

    • DTC B0016 will set when the SDM detects the IPM deployment loop resistance is less than 1.3 ohms for 500 milliseconds.
    • DTC B0017 will set when one of the following conditions occurs:
       - The SDM detects the IPM deployment loop resistance is greater than 4.8 ohms for 500 milliseconds.
       - The SDM detects the voltage at IPM high control is less than 2.4 volts and IPM deployment loop resistance is 6 ohms or greater for 500 milliseconds.
    • DTC B0018 will set when one of the following conditions occurs:
       - The SDM detects the voltage at IPM high control is shorted to ground or voltage for 500 milliseconds.
       - The SDM detects the voltage at IPM high control is less than 2.4 volts and IPM deployment loop resistance is less than 6 ohms for 500 milliseconds.

Action Taken When the DTC Sets

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.
    • 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 IPM high and IPM low control circuits
    • An open or high resistance in the IPM high or IPM low control circuits
    • A malfunctioning shorting bar on the IPM connector

Reference Information

Schematic Reference

SIR Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

SIR System Description and Operation

Electrical Information Reference

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

Scan Tool Reference

Control Module References for scan tool information

Special Tools

J 38715-A Driver and Passenger SIR Load Tool

Circuit/System Testing

Note: Refer to SIR Warning prior to servicing the SIR system.

When removing connectors inspect for damage or corrosion. Damage or corrosion in the following requires repair or replacement of the affected component/connector.

   • The pretensioner
   • The inflatable restraint module
   • The SDM module
   • The inflatable restraint module wiring harness connector
   • The SDM wiring harness connector

  1. Ignition OFF, disconnect the harness connector at the IPM.
  2. Ignition ON, test for less than 1 volt between the high control circuit terminal A and ground.
  3. If greater than the specified range, test the high control circuit for a short to voltage. If the circuit tests normal, replace the SDM.
  4. Test for less than 1 volt between the low control circuit terminal B and ground.
  5. If greater than the specified range, test the low control circuit for a short to voltage. If the circuit tests normal, replace the SDM.
  6. Ignition OFF, test for infinite resistance between the high control circuit terminal A and ground.
  7. If not the specified value, test the high control circuit for a short to ground. If the circuit tests normal, replace the SDM.
  8. Test for infinite resistance between the low control circuit terminal B and ground.
  9. If not the specified value, test the low control circuit for a short to ground. If the circuit tests normal, replace the SDM.
  10. With the applicable adaptor, connect special tool J 38715-A in place of the IPM.
  11. Ignition ON, verify the DTC is set as current.
  12. If the DTC is not set or is set as history, replace the IPM.
  13. Ignition OFF, disconnect special tool J 38715-A and the applicable adaptor.
  14. Disconnect the harness connector at the SDM.
  15. Test for less then 1 ohm between the high control circuit terminals A and A3.
  16. If not within the specified range, test the circuit for an open/high resistance.
  17. Test for less then 1 ohm between the low control circuit terminals B and A8.
  18. If not within the specified range, test the circuit for an open/high resistance.
  19. If all circuits test normal, replace the SDM.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the repair.

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