GM Service Manual Online
For 1990-2009 cars only

Object Number: 612819  Size: SF
SIR Components
SIR Schematics Utilities
SIR Caution
Handling ESD Sensitive Parts Notice

Circuit Description

When you first turn the ignition switch to the RUN position, the inflatable restraint sensing and diagnostic module (SDM) performs tests to diagnose critical malfunctions within itself. The SDM provides input power to the side impact sensor (SIS). When input power is first detected, the SIS responds by performing internal diagnostics. The SIS then sends an ID message to the SDM. The SDM will consider this to be a valid ID if the response time is less than 5 seconds after the SIS is powered up.The SIS will continually communicate a status message to the SDM. The SDM can reset the SIS by removing and applying power to it.

Conditions for Running the DTC

    • Ignition 1 voltage is within the normal operating voltage range.
    • The LF SIS sends an ID message to the SDM.
    • The LF SIS continuously sends an OK or NOK message to SDM.

Conditions for Setting the DTC

The SDM has received a NOK (not OK) message from the LF SIS.

Action Taken When the DTC Sets

The SDM commands ON the AIR BAG warning lamp via Class 2 serial data.

Conditions for Clearing the DTC

    • Replace the LF side impact sensor (SIS).
    • You issue a scan tool CLEAR CODES command.
    • A history DTC will clear once 255 malfunction free ignition cycles have occurred.

When the SDM detects that no DTCs are present, the SDM commands the AIR BAG warning lamp OFF.

Test Description

The following numbers refer to the step numbers in the diagnostic table:

  1. Tests the communication status of the LF inflatable restraint side impact sensor (SIS).

Step

Action

Value(s)

Yes

No

1

Did you perform the SIR Diagnostic System Check?

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Go to Step 2

Go to Diagnostic System Check - SIR

2

  1. Turn OFF the ignition.
  2. Use the scan tool to request the SIR DTC display.
  3. Turn ON the ignition, with the engine OFF.

Does the scan tool indicate that DTC B0080 is current?

--

Go to Step 3

--

3

Replace the LF inflatable restraint side impact sensor (SIS). Refer to Inflatable Restraint Side Impact Sensor Replacement .

Did you complete the replacement?

--

Go to Step 4

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4

  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.

Did you complete the repair?

--

Go to Diagnostic System Check - SIR

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