GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Chevrolet 🢒 2000 🢒 Impala 🢒 Restraints 🢒 SIR 🢒 DTC B0079 Incorrect LF/Driver SIS Installed

Object Number: 490873 Size: SF
SIR Components
Power, Ground, Side Impact Sensor, and Frontal Air Bags
Handling ESD Sensitive Parts Notice
SIR Caution

Circuit Description

When you first turn ON the ignition, the inflatable restraint sensing and diagnostic module (SDM) performs tests to diagnose critical malfunctions within itself. The SDM provides input power to the inflatable restraint side impact sensor (SIS). When input power is first detected, the SIS responds by performing internal diagnostics. Next the SIS 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 SDM monitors the inflatable restraint side impact sensor loop with the ignition ON.

Conditions for Setting the DTC

The SDM has received an ID message from the SIS that does not match the ID stored in the SDM memory.

Action Taken When the DTC Sets
    • The SDM commands ON the AIR BAG warning lamp via Class 2 serial data.
    • The SDM attempts to reset the SIS.

Conditions for Clearing the DTC
    • Current DTC
       - The SDM has detected correct operation.
       - The SIS sends an OK message to the SDM.
    • History DTC
       - You issue a scan tool CLEAR CODES command.
       - Once 255 malfunctions free ignition cycles have occurred.

Diagnostic Aids

DTC B0079 is an indication that the incorrect inflatable restraint side impact sensor (SIS) is installed in the vehicle. Check to make sure that the correct SIS is installed in the vehicle.

Test Description

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

  1. This test checks the communication status of the inflatable restraint side impact sensor.

Step

Action

Value(s)

Yes

No

1

Did you perform A Diagnostic System Check - SIR?

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Go to Step 2

Go to cell-id="57882">A Diagnostic System Check - SIR>

2

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

Does the scan tool indicate that this DTC is current?

--

Go to Step 3

Go to Diagnostic Aids

3

Replace the inflatable restraint side impact sensor (SIS). Refer to cell-id="57813">Inflatable Restraint Side Impact Sensor Replacement>

Did you complete the replacement?

--

Go to Step 4

--

4
  1. Reconnect all SIR components.
  2. Verify that all components and connectors are properly mounted.
  3. Turn ON the ignition, with the engine OFF.
  4. Use the scan tool in order to clear the DTCs.

Did you complete the action?

--

Go to cell-id="57882">A Diagnostic System Check - SIR>

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