GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Chevrolet 🢒 2001 🢒 Prizm 🢒 Restraints 🢒 SIR 🢒 DTC B1140

Circuit Description

The inflatable restraint side impact sensor (SIS) is a crash sensing device used in the detection of a side impact collision. The SIS is used to monitor vehicle velocity changes to detect side impact crashes that are severe enough to warrant deployment of the inflatable restraint side impact module. The SIS receives power and ground from the inflatable restraint sensing and diagnostic module (SDM). The SIS communicates the status of the side impact air bag system to the SDM via a diagnostic line. If the SDM detects a malfunction within the SIS circuit, a DTC will be set.

Conditions for Running the DTC

Ignition 1 Voltage is within the normal operating voltage range.

Conditions for Setting the DTC

The SDM detects a malfunction in the SIS - Right circuits.

Action Taken When the DTC Sets

The SDM commands the AIR BAG indicator to flash.

Conditions for Clearing the DTC

The condition responsible for setting the DTC no longer exists and the scan tool Clear DTCs function is used.

Diagnostic Aids

Thoroughly inspect the wiring and the connectors. An incomplete inspection of the wiring and the connectors may result in a misdiagnosis, causing a part replacement with the reappearance of the malfunction.

The following are possible causes of the malfunction:

    • An open or high resistance in the SIS - Right circuits
    • A short to ground or voltage in the SIS - Right circuits
    • An internal SIS - Right malfunction
    • An internal SDM malfunction

If an intermittent malfunction exists, refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems.

Test Description

The number below refers to the step number on the diagnostic table.

  1. Tests for an open, short to ground, or short to voltage in the SIS - Right circuits.

Step

Action

Yes

No

Schematic Reference: SIR Schematics

1

Did you perform A Diagnostic System Check - SIR?

Go to Step 2

Go to Diagnostic System Check - SIR

2

Is DTC B1140 set as a current DTC?

Go to Step 3

Go to Diagnostic Aids

3
  1. Turn OFF the ignition.
  2. Disconnect the SIS - Right connector.
  3. Inspect both the component and harness sides of the connector for the following conditions:
    4. • Corrosion
    • Damaged terminals
    • Poor contact/terminal tension

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 9

Go to Step 4

4
  1. Disconnect the SDM connector.
  2. Inspect the SDM connector for the following conditions:
    3. • Corrosion
    • Damaged terminals
    • Poor contact/terminal tension

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 9

Go to Step 5

5

Test the SIS - Right circuits for the following conditions:

    • An open or high resistance
    • A short to ground
    • A short to voltage

Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 9

Go to Step 6

6

Replace the Inflatable Restraint Side Impact Sensor (SIS) - Right. Refer to Inflatable Restraint Side Impact Sensor Replacement .

Did you complete the replacement?

Go to Step 7

--

7
  1. Reconnect all SIR 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 8

System OK

8

Replace the SDM. Refer to Inflatable Restraint Sensing and Diagnostic Module Replacement .

Did you complete the replacement?

Go to Step 9

--

9
  1. Reconnect all SIR 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