Diagnostic Instructions

DTC Descriptors

DTC B0085 01: Front Driver Side Impact Sensor Short to Battery

DTC B0085 02: Front Driver Side Impact Sensor Short to Ground

DTC B0085 04: Front Driver Side Impact Sensor Open Circuit

DTC B0085 39: Front Driver Side Impact Sensor Internal Electronic Failure

DTC B0085 71: Front Driver Side Impact Sensor Invalid Serial Data Received

DTC B0085 3A: Front Driver Side Impact Sensor Incorrect Component Installed

DTC B0086 01: Front Passenger Side Impact Sensor Short to Battery

DTC B0086 02: Front Passenger Side Impact Sensor Short to Ground

DTC B0086 04: Front Passenger Side Impact Sensor Open Circuit

DTC B0086 39: Front Passenger Side Impact Sensor Internal Electronic Failure

DTC B0086 71: Front Passenger Side Impact Sensor Invalid Serial Data Received

DTC B0086 3A: Front Passenger Side Impact Sensor Incorrect Component Installed

Diagnostic Fault Information

Circuit	Short to Ground	High Resistance	Open	Short to Voltage	Signal Performance
Front End Sensor 1 High Signal	B0083 02	B0083 04	B0083 04	B0083 01	B0083 3A
Front End Sensor 1 Low Reference	B0083 02	B0083 04	B0083 04	B0083 01	B0083 3A
Front End Sensor 2 High Signal	B0084 02	B0084 04	B0084 04	B0084 01	B0084 3A
Front End Sensor 2 Low Reference	B0084 02	B0084 04	B0084 04	B0084 01	B0084 3A
Left Front Side Impact Sensor High Signal	B0085 02	B0085 04	B0085 04	B0085 01	B0085 3A
Left Front Side Impact Low Reference	B0085 02	B0085 04	B0085 04	B0085 01	B0085 3A
Right Front Side Impact Sensor High Signal	B0086 02	B0086 04	B0086 04	B0086 01	B0086 3A
Right Front Side Impact Low Reference	B0086 02	B0086 04	B0086 04	B0086 01	B0086 3A

Circuit/System Description

The inflatable restraint side impact sensor utilizes a unidirectional 2-wire circuit. The side impact 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 side impact sensor. When the ignition is turned ON and input power from the SDM is first detected, the side impact 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 side impact sensor continually communicates status messages to the SDM, which determines if a fault is present in the side impact sensor circuit. When a fault is detected, the SDM may reset the side impact 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:

B0085 01 or B0086 01

B0085 02 or B0086 02

B0085 04 or B0086 04

The SIS circuit is open

B0085 39 or B0086 39

B0085 71 or B0086 71

The SDM has received invalid serial data from the side impact sensor.

B0085 3A or B0086 3A

Action Taken When the DTC Sets

Conditions for Clearing the DTC

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

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 X2 harness connector at the SDM and the harness connector at the appropriate side impact sensor.
2. Ignition ON, test for less than 1 volt between the side impact sensor low reference circuit terminal 2 and ground.

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

3. Ignition ON, test for less than 1 volt between the side impact sensor signal circuit terminal 1 and ground.

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

4. Test for infinite resistance between the side impact sensor signal circuit terminal 1 and ground.

⇒	If less than the specified value, test the circuit for a short to ground.

5. Test for infinite resistance between the side impact sensor low reference circuit terminal 2 and ground.

⇒	If less than the specified value, test the circuit for a short to ground.

6. Test for less than 1 ohm between the low reference circuit terminals listed below:

•	Right side impact sensor terminal 2 and SDM terminal 28 X2.

•	Left side impact sensor terminal 2 and SDM terminal 25 X2.

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

7. Test for less than 1 ohm between the signal circuit terminals listed below:

•	Right side impact sensor terminal 1 and SDM terminal 27 X2

•	Left side impact sensor terminal 1 and SDM terminal 26 X2.

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

8. If all circuits test normal, replace the side impact sensor. If the DTC resets, replace the SDM.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.