Circuit Description
The body control module (BCM) controls the security lamp via the security indicator signal circuit. When the vehicle theft deterrent (VTD) system or content theft deterrent (CTD) system request the security lamp be illuminated, the BCM grounds the security indicator signal circuit, illuminating the lamp.
DTC Descriptor
This diagnostic procedure supports the following DTC:
DTC B0685 Security System Indicator Circuit
This vehicle has DTCs that include DTC Symptoms. For more information on DTC Symptoms, refer to DTC Symptom Description .
DTC Symptom | DTC Symptom Descriptor |
|---|---|
01 | Short to Battery |
06 | Short to Ground or Open |
Conditions for Running the DTC
The security indicator lamp is requested on by the BCM.
Conditions for Setting the DTC
| • | The BCM detects a short to battery in the security indicator signal circuit. |
| • | The BCM detects a short to ground or an open in the security indicator signal circuit. |
| • | The above conditions are present for more than 1 second. |
Action Taken When the DTC Sets
| • | The BCM stores the DTC to memory. |
| • | Security indicator output is disabled until next ignition cycle. |
Conditions for Clearing the MIL/DTC
| • | A current DTC clears when the malfunction is no long present. |
| • | A history DTC clears when the module ignition cycle counter reaches the reset threshold, without a repeat of the malfunction. |
Diagnostic Aids
A history DTC may be caused by an intermittent short or open in the security indicator signal circuit. Refer to Testing for Intermittent Conditions and Poor Connections .
Step | Action | Yes | No |
|---|---|---|---|
Schematic Reference: Theft Deterrent System Schematics | |||
1 | Did you perform the Diagnostic System Check - Vehicle? | Go to Step 2 | |
2 | Is the security indicator illuminated at all times? | Go to Step 4 | Go to Step 3 |
3 |
Does the security indicator LED illuminate? | Go to Step 6 | Go to Step 5 |
4 | Test the security indicator signal circuit for a short to ground. Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition? | Go to Step 10 | Go to Step 6 |
5 | Test the security indicator signal circuit for an open or short to battery. Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition? | Go to Step 10 | Go to Step 7 |
6 | Inspect for poor connections at the harness connector of the BCM. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs . Did you find and correct the condition? | Go to Step 10 | Go to Step 9 |
7 | Inspect for poor connections at the instrument panel cluster (IPC) harness connector containing the security indicator lamp supply voltage circuit. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs . Did you find and correct the condition? | Go to Step 10 | Go to Step 8 |
8 | Replace the IPC. Refer to Instrument Cluster Replacement . Did you complete the repair? | Go to Step 10 | -- |
9 | Replace the BCM. Refer to Body Control Module Replacement . Did you complete the replacement? | Go to Step 10 | -- |
10 | Operate the system in order to verify the repair. Did you correct the condition? | System OK | Go to Step 2 |
