Circuit Description
The Body Control Module (BCM) controls the courtesy lamps through the theater dimming control circuit. The BCM grounds the theater dimming ground control circuit which completes the courtesy lamps ground circuit, and the lights illuminate.
Conditions for Running the DTC
The BCM must command the theater dimming control feature ON.
Conditions for Setting the DTC
| • | The BCM detects a high when the output should be low in the theater dimming ground control circuit. |
| • | The condition above must be present for more than 0.3 seconds. |
Action Taken When the DTC Sets
The BCM stores DTC B2618 in memory.
Conditions for Clearing the DTC
| • | A current DTC B2618 will clear if the short to battery in the theater dimming ground control circuit is no longer detected by the BCM. |
| • | A history DTC B2618 will clear after 100 consecutive ignition cycles if the condition for the malfunction is no longer present and no other BCM faults are detected. |
Diagnostic Aids
| • | If the DTC B2618 is a history DTC, the fault may be intermittent. Refer to Testing for Intermittent Conditions and Poor Connections . |
| • | The following conditions may cause an intermittent malfunction to occur: |
| - | An intermittent short to battery in the theater dimming ground control circuit |
| - | Any courtesy lamp is intermittently shorted to battery internally |
| - | The BCM is intermittently shorted to battery internally |
Test Description
The number(s) below refer to the step number(s) on the diagnostic table.
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Watch for the courtesy lamps to illuminate. Command both the ON and OFF states. Repeat the commands as necessary.
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Tests for voltage at the courtesy lamps.
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Verifies that the Body Control Module is providing ground to the courtesy lamps.
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Tests if ground is constantly being applied to the courtesy lamps.
Step | Action | Value(s) | Yes | No |
|---|---|---|---|---|
1 | Did you perform the Lighting System Diagnostic System Check? | -- | Go to Step 2 | |
Do the courtesy lamps turn ON and OFF with each command? | -- | Go to Diagnostic Aids | Go to Step 3 | |
Does the test lamp illuminate at each courtesy lamp? | -- | Go to Step 4 | Go to Step 10 | |
Does the test lamp turn ON and OFF with each command? | -- | Go to Step 8 | Go to Step 5 | |
Does the test lamp remain illuminated with each command? | -- | Go to Step 7 | Go to Step 6 | |
6 | Test the control circuit of the courtesy lamps for high resistance or an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 13 | Go to Step 9 |
7 | Test the control circuit of the courtesy lamps for a short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 13 | Go to Step 9 |
8 | Inspect for poor connections at each courtesy lamp. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 13 | Go to Step 11 |
9 | Inspect for poor connections at the harness connector of the Body Control Module. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 13 | Go to Step 12 |
10 | Repair the feed circuit of the courtesy lamps. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair? | -- | Go to Step 13 | -- |
11 | Replace the inoperative courtesy lamp. Did you complete the replacement? | -- | Go to Step 13 | -- |
12 |
Important: Perform the set up procedure for the body control module. Replace the BCM. Refer to Body Control Module Replacement . Did you complete the replacement? | -- | Go to Step 13 | -- |
13 |
Does the DTC reset? | -- | Go to Step 2 | System OK |
