Circuit Description
Battery positive voltage is supplied through the PARK LPS 30 A fuse in the engine wiring harness junction block, to the normally open park lamp relay switch contacts. The panel dimmer switch potentiometer receives both its voltage and ground from the headlamp switch and is an input to the BCM. When the driver selects a dimming setting, all the vacuum florescent (VF) and incandescent back lighting lamps are provided with voltage and then grounded at G200, G203 and G410, so the vacuum florescent (VF) and incandescent back lighting lamps have power and ground and illuminate.
The body control module (BCM) monitors the instrument panel (IP) dimming voltage from the panel dimmer switch potentiometer (thumb wheel), part of the headlamp and panel dimmer switch. The panel dimmer switch potentiometer controls the IP dimming by sending a signal in order to indicate the position of the thumb wheel when the headlamps or parklamps are ON. The dimmer switch also provides dimming for the backlighting of the instrument cluster, the radio and the overhead console.
Conditions for Running the DTC
| • | The battery voltage must be between 9.0 and 16.0 volts. |
| • | Ignition switch in the RUN position. |
| • | The park lamp switch (part of the headlamp and panel dimmer switch) must be in the OFF (AUTO) position and the ambient light sensor must be in the DARK state. |
| • | The park brake released. |
Conditions for Setting the DTC
To set B2613, the following conditions must be present:
| • | The instrument panel lamp supply voltage circuit is shorted to battery voltage. |
| • | The above conditions must be met for 0.5 seconds. |
Action Taken When the DTC Sets
With DTC B2613 set, the instrument panel lights remain full bright at all times.
Conditions for Clearing the 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. |
| • | A clear codes message is sent by the scan tool. |
Diagnostic Aids
Perform a visual inspection for loose or poor connections at all related components. Refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems.
Test Description
The number(s) below refer to the step number(s) on the diagnostic table.
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Tests for the proper operation of the circuit in the low voltage range.
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Tests for the proper operation of the circuit in the high voltage range. If the fuse in the jumper opens when you perform this test, the instrument panel lamp supply voltage circuit is shorted to ground.
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Tests for a short to voltage in the battery positive voltage circuit.
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After replacement of the BCM you must calibrate the new module for proper operation.
Step | Action | Value(s) | Yes | No |
|---|---|---|---|---|
1 | Did you perform the Lighting System Diagnostic System Check? | -- | 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 |
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 | |
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 | |
Does the voltage measure less than the specified value? | 0.1 V | Go to Step 10 | Go to Step 6 | |
6 | Test the battery positive voltage circuit of the Dimming Potentiometer for a short to voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 14 | Go to Step 11 |
7 | Test the battery positive voltage circuit of the Dimming Potentiometer for a short to ground, a 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 14 | Go to Step 8 |
8 | Test the instrument panel lamps dimmer switch circuit of the Dimming Potentiometer for a short to ground, a 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 14 | Go to Step 11 |
9 | Test the instrument panel lamps dimmer switch circuit of the Dimming Potentiometer for a short to voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. 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 Dimming Potentiometer. 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 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 in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 14 | Go to Step 13 |
12 | Replace the Headlamp and Panel Dimmer Switch. Refer to Headlamp Switch Replacement . Did you complete the replacement? | -- | Go to Step 14 | -- |
|
Important: Perform the setup procedure for the body control module. Replace the body control module. Refer to Body Control Module Replacement in Body Control System. Did you complete the replacement? | -- | Go to Step 14 | -- | |
14 |
Does the DTC reset? | -- | Go to Step 2 | System OK |
