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 Descriptors

DTC B0083 01 : Front End Sensor 1 Short to Battery (Left)

DTC B0083 02 : Front End Sensor 1 Short to Ground (Left)

DTC B0083 04 : Front End Sensor 1 Open Circuit (Left)

DTC B0083 39 : Front End Sensor 1 Internal Electronic Failure (Left)

DTC B0083 0F : Front End Sensor 1 Incorrect Component Installed (Left)

DTC B0083 3A : Front End Sensor 1 Invalid Serial Data Received (Left)

DTC B0084 01 : Front End Sensor 2 Short to Battery (Right)

DTC B0084 02 : Front End Sensor 2 Short to Ground (Right)

DTC B0084 04 : Front End Sensor 2 Open Circuit (Right)

DTC B0084 39 : Front End Sensor 2 Internal Electronic Failure (Right)

DTC B0084 0F : Front End Sensor 2 Incorrect Component Installed (Right)

DTC B0084 3A : Front End Sensor 2 Invalid Serial Data Received (Right)

Diagnostic Fault Information

Circuit

Short to Ground

High Resistance

Open

Short to Voltage

Signal Performance

Front End Sensor 1 Low Reference Circuit

--

--

B0083 04

--

--

Front End Sensor 1 Signal Circuit

B0083 02

--

B0083 04

B0083 01

--

Front End Sensor 2 Low Reference Circuit

--

--

B0084 04

--

--

Front End Sensor 2 Signal Circuit

B0084 02

--

B0084 04

B0084 01

--

Circuit/System Description

The inflatable restraint front end sensor also known as the electronic frontal sensor (EFS) utilizes a unidirectional 2-wire circuit. The front end sensor modulates current on the interface to send ID, State of Health, and deployment commands to the inflatable restraint sensing and diagnostic module (SDM). The SDM serves as a power source and a ground for the front end sensor. When the ignition is turned on and input power from the SDM is first detected, the front end sensor responds by performing internal diagnostics and sending an ID to the SDM. The SDM considers the ID to be valid if the response time is less than 5 seconds. The front end sensor continually communicates status messages to the SDM, which determines if a fault is present in the front end sensor circuit. When a fault is detected, the SDM may reset the front end sensor up to 2 times by removing and reapplying power to it. If the fault is still present, the SDM will set a diagnostic trouble code (DTC).

Conditions for Running the DTC

Ignition voltage is between 9-16 volts.

Conditions for Setting the DTC

All of the following conditions exist for 2.5 seconds:

B0083 01 or B0084 01

    • The front end sensor has been shorted to voltage.
    • The SDM has not received a message from the front end sensor for more than 375 milliseconds.

B0083 02 or B0084 02

    • The front end sensor has been shorted to ground.
    • The front end sensor current has been above 23 mA for longer than 5 milliseconds.

B0083 04 or B0084 04

The front end sensor circuit is open.

B0083 39 or B0084 39

    • The SDM has received a NOK message from the front end sensor.
    • The SDM has not received a message.

B0083 71 or B0084 71

The SDM has received invalid serial data from the front end sensor.

B0083 0F or B0084 0F

The SDM has received erratic messages from the front end sensor.

B0083 3A or B0084 3A

    • The SDM has received an ID message from the front end sensor which does not match the ID stored in the SDM memory.
    • The SDM has reset the front end sensor twice without detecting the correct ID message.

Action Taken When the DTC Sets

    • The SDM commands the AIR BAG indicator ON via serial data communications.
    • The SIR System is disabled and no deployments are allowed.

Conditions for Clearing the DTC

    • The condition responsible for setting the DTC no longer exists and the scan tool Clear DTCs function is used.
    • A history DTC will clear once 255 malfunction-free ignition cycles have occurred.

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

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

       • The front end sensor
       • The SDM module
       • The front end sensor wiring harness connector
       • The SDM wiring harness connector

  1. Ignition ON, if DTC B0083 is current, disconnect the front end sensor - left connector. If DTC B0084 is current, disconnect the front end sensor - right connector.
  2. Remove the SDM connector.
  3. Test the signal and voltage circuits between the SDM and front end sensor for a short to voltage, short to ground, or open/low resistance. Verify that a short to voltage, short to ground, or open/low resistance does not exist.
  4. If any of the above conditions are found make the appropriate repair.
  5. Reconnect all SIR components. With the ignition ON use the scan tool to clear the DTCs then recheck for DTCs to be cleared.
  6. If DTC B0083 was current replace the front end sensor - left. If DTC B0084 was current replace the front end sensor - right. After replacement refer to Repair Verification.

Repair Instructions

    •  Inflatable Restraint Front End Sensor Replacement
    •  SIR/SRS Wiring Repairs
    •  Control Module References for SDM replacement, setup, and programming

Repair Verification

With the ignition ON use the scan tool to clear the DTCs then recheck for DTCs.

If DTC B0083 or B0084 was current replace the SDM.