For 1990-2009 cars

### 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)

### 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 commands the AIR BAG indicator ON via serial data communications.

• | 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

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 OFF, disconnect the appropriate front end sensor harness connector.
2. Remove the SDM connector.
3. Ignition ON, 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.

⇒ | If any of the above conditions are found, make the appropriate repair.

4. Reconnect all SIR components. With the ignition ON, use the scan tool to clear the DTCs then recheck for DTCs.

⇒ | If DTC is set as current, replace the appropriate front end sensor.

### Repair Instructions

• | Inflatable Restraint Front End Sensor Replacement

• | SIR/SRS Wiring Repairs

• | 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.