B0086

DTC B0086

Circuit 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.

DTC Descriptor

This diagnostic procedure supports the following DTC:

DTC B0086 RF/Passenger Side Impact Sensor

This vehicle has DTCs which include DTC Symptoms. For more information on DTC Symptoms, refer to DTC Symptom Description. DTC Symptom Description






Conditions for Running the DTC

Ignition 1 voltage is within the normal operating voltage range of 9-16 volts.

Conditions for Setting the DTC

All of the following conditions exist for 2.5 seconds:

B0086 01
* The SIS has been shorted to voltage.
* The SDM has not received a message from the SIS for more than 375 milliseconds.

B0086 02
* The SIS has been shorted to ground.
* The SIS current has been above 23 mA for longer than 5 milliseconds.

B0086 04

The SIS circuit is open.

B0086 39
* The SDM has received a NOK message from the SIS.
* The SDM has not received a message

B0086 71

The SDM has received invalid serial data from the SIS.

B0086 0F

The SDM has received erratic messages from the SIS.

B0086 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 ON the AIR BAG warning lamp via GMLAN serial data.

Conditions for Clearing the MIL/DTC

* The DTC will clear when 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.

Diagnostic Aids

The following are conditions that may cause the malfunction:

* An open in the SIS circuit
* A short to ground or voltage in the SIS circuit
* High or low resistance in the SIS circuit
* Improper SIS installed on vehicle
* An internal failure in the SIS

Thoroughly inspect the wiring and the connectors. An incomplete inspection of the wiring and connectors may result in misdiagnosis, causing a part replacement with the reappearance of the malfunction. If an intermittent malfunction exists, refer to Testing for Intermittent Conditions and Poor Connections in Diagnostic Aids. Component Tests and General Diagnostics

Test Description

Step 1 - Step 10:

Step 11 - Step 13:

The numbers below refer to the step numbers on the diagnostic table.
7. This step tests the SIS signal and SIS voltage circuits for an open or high resistance.
8. This step tests between the SIS signal and SIS voltage circuits for continuity.
9. his step tests the SIS signal and SIS voltage circuits for a short to voltage.