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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 Descriptors

DTC B0685 01: Security Indicator Circuit Short to Battery

DTC B0685 02: Security Indicator Circuit Short to Ground

DTC B0685 04: Security Indicator Circuit Open

Diagnostic Fault Information

Circuit

Short to Ground

Open/High Resistance

Short to Voltage

Signal Performance

Security LED Control

B0685 02

B0685 04

B0685 01

--

Ground

--

B0685 04

--

--

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 at least 9 V and no more than 16 V.

Conditions for Setting the DTC

P0685 01

The BCM detects a short to voltage on the security indicator control circuit.

P0685 02

The BCM detects a short to ground on the security indicator control circuit.

P0685 04

The BCM detects an open in the security indicator control circuit.

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

Connector End View Reference

Component Connector End Views

Description and Operation

Content Theft Deterrent (CTD) Description and Operation

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 indicator should illuminate and/or flash during the arming sequence.

Circuit/System Testing

  1. Ignition OFF, remove the ignition key, open the driver door, disconnect the scan tool and disconnect the harness connector at the B10B Ambient Light/Sunload Sensor.
  2. Wait for 1 min, test for less than 5 Ω between the low reference circuit terminal 6 and ground.
  3. [ARW-LISTFAIL]
  4. If greater than 5 Ω

    Repair the open/high resistance in the circuit.

  5. [/ARW-LISTFAIL][ARW-LISTPASS]
  6. If less than 5 Ω

  7. [/ARW-LISTPASS]
  8. Connect a test lamp between the control circuit terminal 1 and ground.
  9. Ignition ON, command the security LED ON and OFF with a scan tool. The test lamp should turn ON and OFF when changing between the commanded states.
  10. [ARW-LISTFAIL]
  11. If the test lamp always illuminates

  12. [/ARW-LISTFAIL]
    4.1. Ignition OFF, disconnect the X1 harness connector at the K9 Body Control Module.
    4.2. Ignition ON, test for less than 0.3 V between the control circuit and ground.
    [ARW-LISTFAIL]
  13. If greater than 0.3 V, repair the short to voltage on the circuit.

  14. If less than 0.3 V, replace the K9 Body Control Module.

  15. [/ARW-LISTFAIL] [ARW-LISTFAIL]
  16. If the test lamp does not illuminate

  17. [/ARW-LISTFAIL]
    4.1. Ignition OFF, disconnect the X1 harness connector at the K9 Body Control Module.
    4.2. Test for infinite resistance between the control circuit and ground.
    [ARW-LISTFAIL]
  18. If less than infinite resistance, repair the short to ground on the circuit.

  19. [/ARW-LISTFAIL][ARW-LISTPASS]
  20. If infinite resistance

  21. [/ARW-LISTPASS]
    4.3. Ignition OFF, test for less than 2 Ω in the control circuit end to end.
    [ARW-LISTFAIL]
  22. If 2 Ω or greater, repair the open/high resistance in the circuit.

  23. If less than 2 Ω, replace the K9 Body Control Module.

  24. [/ARW-LISTFAIL] [ARW-LISTPASS]
  25. If the test lamp illuminates as commanded

  26. [/ARW-LISTPASS]
  27. Replace the B10B Ambient Light/Sunload Sensor.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

    •  Sun Load Temperature and Headlamp Automatic Control Ambient Light Sensor Replacement
    • Control Module References for BCM replacement, setup, and programming
   


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