Circuit Description
The body control module (BCM) monitors the instrument panel (I/P) lamps dimming control circuit to determine the lighting intensity of the I/P lamps. When the BCM receives a varied voltage signal on the I/P lamps dimming control circuit, it applies a corresponding pulse width modulated (PWM) voltage signal through the I/P lamps supply voltage circuit to all the I/P lamps.
DTC Descriptor
This diagnostic procedure supports the following DTC:
DTC B2613 Passenger Compartment Dimming Circuit High
Conditions for Running the DTC
| • | The battery voltage must be between 9-16 volts. |
| • | The ignition switch is in the RUN position. |
| • | The headlamp switch, must be in the OFF or AUTO position and the ambient light sensor must be in the low light state. |
| • | The park brake is released. |
Conditions for Setting the DTC
To set B2613, the following conditions must be present:
| • | The I/P lamps dimming control circuit is shorted to battery voltage. |
| • | The above conditions must be met for 1 second. |
Action Taken When the DTC Sets
The I/P lights remain full bright at all times.
Conditions for Clearing the MIL/DTC
| • | A current DTC will clear at the next fault-free ignition cycle. |
| • | A history DTC will clear after 100 consecutive ignition cycles without a fault present. |
| • | Use a scan tool in order to clear history and current DTCs. |
Diagnostic Aids
| • | If the DTC 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 positive voltage in the I/P lamps dimming control circuit |
| - | A poor connection or an intermittent open in the low reference circuit |
| - | The I/P dimmer switch is intermittently shorted to battery positive voltage. |
| - | The BCM is intermittently shorted to battery positive voltage. |
Step | Action | Value(s) | Yes | No |
|---|---|---|---|---|
Schematic Reference: Interior Lights Dimming Schematics Connector End View Reference: Master Electrical Component List . | ||||
1 | Did you perform the Diagnostic System Check - Vehicle? | -- | Go to Step 2 | |
2 |
Does the scan tool indicate that the dimming potentiometer parameter is within the specified range? | 0.1-13.5 V | Go to Diagnostic Aids | Go to Step 3 |
3 |
Does the scan tool indicate that the dimming potentiometer parameter is less than the specified value? | 0.1 V | Go to Step 4 | Go to Step 9 |
4 |
Does the scan tool indicate that the dimming potentiometer parameter is greater than the specified value? | 13.5 V | Go to Step 5 | Go to Step 7 |
5 |
Does the test lamp illuminate? | 0.1 V | Go to Step 6 | Go to Step 10 |
6 | Test the I/P lamps low reference circuit for a short to voltage. Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition? | -- | Go to Step 14 | Go to Step 11 |
7 | Test the I/P lamp low reference circuit for a short to ground, a high resistance, or an open. Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition? | -- | Go to Step 14 | Go to Step 8 |
8 | Test the I/P lamps dimming control circuit for a short to ground, a high resistance, or an open. Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition? | -- | Go to Step 14 | Go to Step 11 |
9 | Test the I/P lamps dimming control circuit for a short to voltage. Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition? | -- | Go to Step 14 | Go to Step 11 |
10 | Inspect for poor connections at the harness connector of the I/P dimmer switch. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs . Did you find and correct the condition? | -- | Go to Step 14 | Go to Step 12 |
11 | 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 14 | Go to Step 13 |
12 | Replace the I/P dimmer switch. Refer to Instrument Panel Lamp Dimmer Switch Replacement . Did you complete the replacement? | -- | Go to Step 14 | -- |
13 | Replace the BCM. Refer to Control Module References for replacement, setup, and programming. Did you complete the replacement? | -- | Go to Step 14 | -- |
14 |
Does the DTC reset? | -- | Go to Step 2 | System OK |
