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 B0085 01 : Left Front/Driver Side Impact Sensor Short to BatteryDTC B0085 02 : Left Front/Driver Side Impact Sensor Short to Ground
DTC B0085 04 : Left Front/Driver Side Impact Sensor Open Circuit
DTC B0085 39 : Left Front/Driver Side Impact Sensor Internal Electronic Failure
DTC B0085 0F : Left Front/Driver Side Impact Sensor Incorrect Component Installed
DTC B0085 3A : Left Front/Driver Side Impact Sensor Invalid Serial Data Received
Diagnostic Fault Information
Circuit | Short to Ground | High Resistance | Open | Short to Voltage | Signal Performance |
|---|---|---|---|---|---|
Side Impact Sensor LF Signal Circuit | -- | -- | B0085 04 | -- | -- |
Side Impact Sensor Voltage Circuit | B0085 02 | -- | B0085 04 | B0085 01 | -- |
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, 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:
B0085 01
| • | The SIS has been shorted to voltage. |
| • | The SDM has not received a message from the SIS for more than 375 milliseconds. |
B0085 02
| • | The SIS has been shorted to ground. |
| • | The SIS current has been above 23 mA for longer than 5 milliseconds. |
B0085 04
The SIS circuit is open.
B0085 39
| • | The SDM has received a NOK message from the SIS. |
| • | The SDM has not received a message. |
B0085 71
The SDM has received invalid serial data from the SIS.
B0085 0F
The SDM has received erratic messages from the SIS.
B0085 3A
| • | 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 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
Connector End View Reference
Electrical Information Reference
Circuit/System Testing
- Ignition OFF, disconnect the left SIS connector.
- Remove the SDM connector.
- Test the signal and voltage circuits between the SDM and SIS 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.
- Reconnect all SIR components. With the ignition ON use the scan tool to clear the DTCs then recheck for DTCs to be cleared.
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
| ⇒ | If any of the above conditions are found make the appropriate repair. |
| ⇒ | If DTC B0085 was current replace the SIS - left. After replacement refer to Repair Verification. |
Repair Instructions
| • | 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 B0085 was current replace the SDM. |
