• | Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. |
• | Review Strategy Based Diagnosis for an overview of the diagnostic approach. |
• | Diagnostic Procedure Instructions provides an overview of each diagnostic category. |
Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance |
---|---|---|---|---|
Instrument Panel Lamp Dimmer Switch Signal | B3600 03 | B3600 03 | B3600 07 | B3600 03 or B3600 07 |
Reference Voltage | B1395 03 and B3600 07 | B1395 03 and B3600 07 | B1395 07 | B1395 03, B1395 07 and B3600 03, B3600 07 |
Voltage for the interior backlighting components is supplied from the body control module (BCM). The BCM applies a voltage reference through the 12-volt reference circuit to the headlamp and panel dimmer switch. When the dimming switch is placed in the desired position, the dimmed voltage setting is applied from the headlamp and panel dimmer switch through the instrument panel (I/P) lamp dimmer switch signal circuit to the BCM. The BCM then applies the dimmed voltage to the lamp supply voltage circuits and they are dimmed to the correct level.
The ignition is ON.
The BCM detects a voltage that is lower than 0.10 volt on the I/P lamp dimmer switch signal circuit.
The BCM detects a voltage that is higher than 4.97 volts on the I/P lamp dimmer switch signal circuit.
The I/P lamps are not illuminated.
The BCM clears this code from current when the fault is removed from the system.
Interior Lights Dimming Schematics
Lighting Systems Connector End Views
Ignition ON, headlamp switch to HEAD, vary the interior lamp dimming switch from dim to full bright. The I/P lamps should dim and then become full bright.
⇒ | If the lamps cannot be controlled with the scan tool, replace the BCM. |
⇒ | If the circuit/connections test normal, replace the headlamp and panel dimmer switch. |
⇒ | If the circuit/connections test normal, replace the headlamp and panel dimmer switch. |
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
• | Control Module References for BCM replacement, setup, and programming |