Circuit Description
The body control module (BCM) uses a varying voltage signal from the instrument panel (I/P) dimmer switch in order to determine the rate of pulse width modulation of the control circuit of the illumination lamps. The pulse width modulation rate determines the brightness of the illumination lamps.
DTC Descriptor
This diagnostic procedure supports the following DTC:
DTC B2613 Dimming Input Circuit High
Conditions for Running the DTC
Voltage supplied to the module is in the normal operating range, approximately 10-16 volts.
Conditions for Setting the DTC
| • | The BCM detects one of the following conditions: |
| - | A short to voltage in the 12-volt reference circuit of the I/P dimmer switch. |
| - | A short to voltage in the dimming circuit of the I/P dimmer switch. |
| - | An open in the low reference circuit of the I/P dimmer switch. |
| • | The condition is present for longer than 1 second. |
Action Taken When the DTC Sets
| • | The BCM stores DTC B2613 in memory. |
| • | The illumination lamps remain at full brightness until the code is cleared. |
Conditions for Clearing the MIL/DTC
| • | A current DTC B2613 clears when the BCM no longer detects one of the above conditions. |
| • | A history DTC B2613 clears after 100 consecutive ignition cycles. |
| • | The BCM receives the Clear Code command from the scan tool. |
Diagnostic Aids
| • | If the DTC B2613 is a history DTC, the fault may be intermittent. Refer to Testing for Intermittent Conditions and Poor Connections . |
| • | An intermittent condition in the following locations may cause an intermittent malfunction to occur: |
| - | The 12-volt reference circuit of the I/P dimmer switch, the signal circuit of the I/P dimmer switch, or the low reference circuit of the I/P dimmer switch |
| - | The I/P dimmer switch |
| - | The BCM |
Step | Action | Values | 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 Switch parameter is within the specified range? | 2-6 V | Go to Diagnostic Aids | Go to Step 3 |
3 |
Does the scan tool indicate that the Dimming Switch parameter is greater than the specified value? | 6 V | Go to Step 4 | Go to Step 7 |
4 | Test the 12-volt reference circuit of the I/P dimmer switch for a short to voltage. Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition? | -- | Go to Step 12 | Go to Step 5 |
5 | Test the signal circuit of the I/P dimmer switch for a high resistance or an open. Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition? | -- | Go to Step 12 | Go to Step 6 |
6 | Test the signal circuit of the I/P dimmer switch for a short to voltage. Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition? | -- | Go to Step 12 | Go to Step 9 |
7 |
Did you find and correct the condition? | -- | Go to Step 12 | Go to Step 8 |
8 | Inspect for a high resistance 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 12 | Go to Step 10 |
9 | Inspect for a high resistance 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 12 | Go to Step 11 |
10 | Replace the I/P dimmer switch. Refer to Headlamp Switch Replacement . Did you complete the replacement? | -- | Go to Step 12 | -- |
11 | Replace the BCM. Refer to Control Module References for replacement, setup, and programming. Did you complete the replacement? | -- | Go to Step 12 | -- |
12 |
Does the DTC reset? | -- | Go to Step 2 | System OK |
