For 1990-2009 cars

### Diagnostic Instructions

• | Perform the Diagnostic System Check - Vehicle prior to using the 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 B0086 02: RF Side Impact Sensor (SIS) Short to Ground
DTC B0086 05: RF Side Impact Sensor (SIS) Short to Battery or Open
DTC B0086 0F: RF Side Impact Sensor (SIS) Erratic
DTC B0086 39: RF Side Impact Sensor (SIS) Internal Electronic Failure
DTC B0086 3A: RF Side Impact Sensor (SIS) Incorrect Component Installed
DTC B0086 71: RF Side Impact Sensor (SIS) Invalid Serial Data Received

### Diagnostic Fault Information

Circuit | Short to Ground | High Resistance | Open | Short to Voltage | Signal Performance
--- | --- | --- | --- | --- | ---
Side Impact Sensor Left Signal Circuit | -- | -- | B0086 05 | -- | B0086 71
Side Impact Sensor Left Voltage Circuit | B0086 02 | B0086 05 | B0086 05 | B0086 05 | B0086 71

### Circuit/System Description

The inflatable restraint side impact sensor (SIS) utilizes a unidirectional 2-wire circuit. The SIS modulates current on the interface to send ID, state of health (SOH), and deployment commands to the inflatable restraint sensing and diagnostic module (SDM). The SDM serves as a power source and a ground for the SIS. When the ignition is turned ON and input power from the SDM is first detected, the SIS 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 SIS continually communicates status messages to the SDM, which determines if a fault is present in the SIS circuit. When a fault is detected, the SDM resets the SIS twice 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:

#### B0086 02, 05

• | The wiring of the SIS is open or shorted to voltage/ground for 500 milliseconds.

• | The wiring of the SIS is shorted to voltage for 500 milliseconds.

#### B0086 0F

• | A valid ID message is not received within 5 seconds of the SIS being powered up.

• | The SDM has not received a message from the SIS for more than 375 milliseconds.

• | The SDM has reset the SIS twice without detecting a valid ID message.

#### B0086 3A, 71

• | The SDM has received an ID message from the SIS which does not match the ID stored in the SDM memory.

• | The SDM has reset the SIS twice without detecting a correct ID message.

#### B0086 39

The SDM has received a NOK message from the SIS.

### 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

Component 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 SIS

• | The SDM module

• | The SIS wiring harness connector

• | The SDM wiring harness connector

1. Ignition ON, use the scan tool as clear SIR codes then recheck for DTCs. Verify that DTC B0079, B0080, B0081, or B0082 is not set.

⇒ | If DTC B0086 39 or B0086 3A is set current, replace the SIS right.

2. If DTC B0086 02, 05, 0F, 71 is current, disconnect the right SIS connector. Refer to SIS replacement in Repair Instructions for location of connector.
3. Remove the SDM connector. Refer to SDM replacement in repair instructions for connector location.
4. Test the signal and voltage circuits between the SDM and SIS. 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.

5. Reconnect all SIR components. Ignition ON, use the scan tool to clear the DTCs then recheck for DTCs. Verify no DTCs are set.

⇒ | If DTC B0086 was current, replace the right SIS. After replacement, refer to Repair Verification.

### Repair Instructions

• | Inflatable Restraint Side Impact 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. Verify no DTCs are set.

⇒ | If DTC B0086 was current, replace the SDM.