Service Information

Cruze

DTC B0685

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 Descriptor

DTC B0685 02: Security System Indicator Circuit Short to Ground

Diagnostic Fault Information

Circuit	Short to Ground	Open/High Resistance	Short to Voltage	Signal Performance
Security LED Control	B0685 02	1	1	--
Ground	--	1	--	--
1. Security Indicator Malfunction

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 at least 9 V and no more than 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

Electrical Information Reference

•	Circuit Testing

•	Connector Repairs

•	Testing for Intermittent Conditions and Poor Connections

•	Wiring Repairs

Scan Tool Reference

Control Module References 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

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

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

Ignition ON, test for less than 1V between the control circuit terminal 1 and ground.

⇒	If greater than the specified range, test the control circuit for a short to voltage. If the circuit tests normal, replace the K9 BCM.

Command the security LED ON. Test for B+ between the control circuit terminal 1 and ground.

⇒	If less than the specified range, test the control circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the K9 BCM.

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

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Control Module References for BCM replacement, setup, and programming