B0685

DTC B0685

Diagnostic Instructions

* Perform the Diagnostic System Check - Vehicle (Diagnostic System Check - Vehicle) prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis (Strategy Based Diagnosis) for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions (Diagnostic Procedure Instructions) provides an overview of each diagnostic category.

DTC Descriptor
DTC B0685 02
- Security System Indicator Circuit Short to Ground

Diagnostic Fault Information





Circuit/System Description

The security LED is controlled by the body control module (BCM) based on commands from the content theft deterrent system. The security LED is located in the dash as part of the ambient light sensor and is supplied ground at all times. When the content theft deterrent system requests the LED be commanded ON, the BCM applies voltage to the security indicator control circuit, illuminating the LED.

Conditions for Running the DTC

The system voltage is between 9-16 V.

Conditions for Setting the DTC

* The BCM detects a short to ground on the security indicator control circuit.
* The above condition exist for 1 second.

Action Taken When the DTC Sets

Security LED output is disabled

Conditions for Clearing the DTC

* A current DTC is cleared when the conditions for setting the DTC are no longer present.
* A history DTC will clear after 40 malfunction free ignition cycles.

Reference Information
Schematic Reference

Theft Deterrent System Schematics (Theft Deterrent System Schematics)
Connector End View Reference

Component Connector End Views (Connector End Views By Name)
Description and Operation

Content Theft Deterrent (CTD) Description and Operation (Content Theft Deterrent (CTD))
Electrical Information Reference

* Circuit Testing (Circuit Testing)
* Connector Repairs (Connector Repairs)
* Testing for Intermittent Conditions and Poor Connections (Testing For Intermittent Conditions and Poor Connections)
* Wiring Repairs (Wiring Repairs)

Scan Tool Reference

Control Module References (Programming and Relearning) for scan tool information

Circuit/System Verification

Arm the content theft deterrent system. The security LED should illuminate and/or flash during the arming sequence.

Circuit/System Testing

1. Ignition OFF, disconnect the harness connector at the B10B Ambient Light/Sunload Sensor.
2. Test for less than 10 ohm between the low reference circuit terminal 6 and ground.

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

3. Connect a test lamp between the control circuit terminal 1 and ground.
4. Ignition ON, command the security indicator ON and OFF with a scan tool. The test lamp should turn ON and OFF when changing between the commanded states.

• If the test lamp is always ON, test the control circuit for a short to voltage. If the circuit tests normal, replace the K9 BCM.
• If the test lamp is always OFF, test the control circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the K9 BCM.

5. If all circuits test normal, replace the B10B Ambient Light/Sunload Sensor.

Repair Instructions

Perform the Diagnostic Repair Verification (Verification Tests) after completing the diagnostic procedure.

* Headlamp Automatic Control Ambient Light Sensor Replacement (Service and Repair)
* Control Module References (Programming and Relearning) for BCM replacement, programming and setup