GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Cadillac 🢒 2008 🢒 STS 🢒 DTC 🢒 DTC B0083 or B0084

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 and overview of each diagnostic category.

DTC Descriptors

DTC B0083 00: Front End Sensor 1 No Additional Information (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 00: Front End Sensor 2 No Additional Information (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

Left Front Discriminating Sensor Signal

B0083 02

B0083 04

B0083 04

B0083 01

--

Left Front Discriminating Low Reference

--

B0083 04

B0083 04

B0083 01

--

Right Front Discriminating Sensor Signal

B0084 02

B0084 04

B0084 04

B0084 01

--

Right Front Discriminating Low Reference

--

B0084 04

B0084 04

B0084 01

--

Circuit/System Description

The inflatable restraint front end sensor 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 DTC.

Conditions for Running the DTC

Ignition voltage is between 9-16 volts.

Conditions for Setting the DTC

B0083 00 or B0084 00

    • The front end sensor has been shorted to voltage, open, or shorted to ground.
    • The front end sensor current has been above 23 mA for longer than 5 milliseconds.
    • The SDM has not received a message from the front end sensor for more than 375 milliseconds.

B0083 39 or B0084 39

    • The SDM has received a NOK message from the front end sensor.
    • The SDM has not received a message.
    • 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 requests the instrument panel cluster (IPC) to illuminate the AIR BAG indicator.
    • The frontal SIR System is disabled and no frontal deployments are allowed. Side deployments and rollover detection is still enabled.

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 100 malfunction-free ignition cycles have occurred.

Reference Information

Schematic Reference

SIR Schematics

Connector End View Reference

Component Connector End Views

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

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:

       • Front end sensor
       • SDM module
       • Front end sensor wiring harness connector
       • SDM wiring harness connector

  1. Ignition OFF, disconnect the harness connector at the applicable front end sensor and the harness connector at the SDM.
  2. Test for infinite resistance between the applicable impact sensor signal circuit terminal A and ground.
    3. ⇒If less than the specified value, test the circuit for a short to ground.
  3. Ignition ON, test for less than 1 volt between the applicable impact sensor signal circuit terminal A and ground.
    4. ⇒If greater than the specified range, test the circuit for a short to voltage.
  4. Ignition ON, test for less than 1 volt between the applicable impact sensor low reference circuit terminal B and ground.
    5. ⇒If greater than the specified range, test the circuit for a short to voltage.
  5. Ignition ON, test for less than 1 volt between the low reference circuit terminal B and ground.
    6. ⇒If greater than the specified range, test the low reference circuit for a short to voltage.
  6. Test for less then 5 ohms between the appropriate signal circuit terminals listed below:
    7. • Left front end sensor terminal A and SDM terminal 39
    • Right front end sensor terminal A and SDM terminal 36
    ⇒If greater than the specified range, test the signal circuit for an open/high resistance.
  7. Test for less then 5 ohms between the appropriate low control circuit terminals listed below:
    8. • Left front end sensor terminal B and SDM terminal 38
    • Right front end sensor terminal B and SDM terminal 37
    ⇒If greater than the specified range, test the control circuit for an open/high resistance.
  8. If all circuits test normal, replace the appropriate impact sensor.
  9. Clear DTCs and cycle the ignition OFF then ON. Verify the DTC B0083 or B0084 is not set.
    10. ⇒If the DTC sets, replace the SDM.

Repair Instructions
    •  Inflatable Restraint Front End Sensor Replacement
    •  Control Module References for SDM replacement, setup, and programming

Repair Verification

Ignition ON, use the scan tool to clear the DTCs, then recheck for DTCs.

⇒If DTC B0083 or B0084 was current, replace the SDM.