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 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 05: Front End Sensor 1 Short to Battery or Open (Left)
DTC B0083 0F: Front End Sensor 1 Erratic (Left)
DTC B0083 39: Front End Sensor 1 Internal Electronic Failure (Left)
DTC B0083 3A: Front End Sensor 1 Incorrect Component Installed (Left)
DTC B0083 71: 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 05: Front End Sensor 2 Short to Battery or Open (Right)
DTC B0084 0F: Front End Sensor 2 Erratic (Right)
DTC B0084 39: Front End Sensor 2 Internal Electronic Failure (Right)
DTC B0084 3A: Front End Sensor 2 Incorrect Component Installed (Right)
DTC B0084 71: 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 High Signal | B0083 02 | B0083 0F | B0083 04 | B0083 01 | B0083 0F
Front End Sensor 1 Low Reference | B0083 02 | B0083 0F | B0083 04 | B0083 01 | B0083 0F
Front End Sensor 2 High Signal | B0084 02 | B0084 0F | B0084 04 | B0084 01 | B0084 0F
Front End Sensor 2 Low Reference | B0084 02 | B0084 0F | B0084 04 | B0084 01 | B0084 0F
Left Front Side Impact Sensor High Signal | B0085 02 | B0085 0F | B0085 04 | B0085 01 | B0085 0F
Left Front Side Impact Low Reference | B0085 02 | B0085 0F | B0085 04 | B0085 01 | B0085 0F
Right Front Side Impact Sensor High Signal | B0086 02 | B0086 0F | B0086 04 | B0086 01 | B0086 0F
Right Front Side Impact Low Reference | B0086 02 | B0086 0F | B0086 04 | B0086 01 | B0086 0F

### 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

All of the following conditions exist for 2.5 seconds:

#### B0083 01 or B0084 01

The front end sensor has been shorted to voltage.

#### B0083 02 or B0084 02

• | The front end sensor has been shorted to ground.

• | The front end sensor current is greater than 23 mA for longer than 5 milliseconds.

#### B0083 05 or B0084 05

• | The front end sensor has been shorted to voltage.

• | The front end sensor circuit is open.

• | The SDM has not received a message from the front end sensor for greater than 375 milliseconds.

#### B0083 0F or B0084 0F

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

#### 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 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.

#### B0083 71 or B0084 71

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

### Action Taken When the DTC Sets

• | The SDM requests the instrument panel cluster (IPC) to illuminate the AIR BAG indicator.

• | The SIR System is disabled and no deployments are allowed.

### Conditions for Clearing the DTC

• | The condition for setting the DTC no longer exists.

• | 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

#### Description and Operation

SIR System Description and Operation

#### Electrical Information Reference

• | Circuit Testing

• | Testing for Intermittent Conditions and Poor Connections

• | Connector Repairs

• | Wiring Repairs

#### Scan Tool Reference

Control Module References for scan tool information

### Circuit/System Testing

Important: Refer to SIR Service Precautions.

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 appropriate front end sensor connector.
2. Disconnect the harness connector at the SDM.
3. Ignition ON, test for less than 1 volt between the front end sensor signal circuit terminal B and ground.

⇒ | 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 appropriate front end sensor low reference circuit terminal A and ground.

⇒ | If greater than the specified range, test the circuit for a short to voltage.

5. Test for infinite resistance between the front end sensor signal circuit terminal B and ground.

⇒ | If less than infinite resistance, test the circuit for a short to ground.

6. Test for less than 1 ohm between the following front end sensor signal circuit terminals.

• | Right front end sensor terminal B and SDM harness connector terminal 37.

• | Left front end sensor terminal B and SDM harness connector terminal 36.

⇒ | If greater than the specified range, test the circuit for an open/high resistance.

7. Test for less than 1 ohm between the following front end sensor low reference circuit terminals.

• | Right front end sensor terminal A and SDM harness connector terminal 39.

• | Left front end sensor terminal A and SDM harness connector terminal 38.

⇒ | If greater than the specified range, test the circuit for an open/high resistance.

8. If all circuits test normal, replace the appropriate front end sensor.
9. Reconnect all SIR components. Ignition ON, with a scan tool clear and recheck for DTCs.

⇒ | If the front end sensor DTC returns and is current, replace the SDM.

### Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

• | Inflatable Restraint Front End Sensor Replacement

• | SIR/SRS Wiring Repairs

• | Control Module References for SDM replacement, setup, and programming