Diagnostic Instructions
DTC Descriptors
DTC B3600 03: Voltage Below Threshold
DTC B3600 07: Voltage Above Threshold
Diagnostic Fault Information
Circuit
| Short to Ground
| Open/High Resistance
| Short to Voltage
| Signal Performance
|
I/P Dimming Voltage Reference
| B1395 03
| B1395 03
| B1395 07
| B1395 03, B1395 07
|
I/P Dimming Control Circuit
| B3600 03
| B3600 03
| B3600 07
| B3600 03, B3600 07
|
Circuit/System Description
Voltage for the interior backlighting components is supplied from the CHMSL/DIMR in the instrument panel I/P electrical center to the body control module (BCM). The BCM applies a voltage reference through the instrument panel (I/P) dimming voltage reference
circuit to the interior lamp dimming switch, which is part of the headlamp switch. Which is part of the turn signal multi function switch. When the dimming switch is placed in the desired position, the dimmed voltage setting is applied from the interior lamp
dimming switch through the I/P dimming control circuit to the BCM. The BCM then applies the dimmed voltage to the I/P lamps supply voltage circuit and they dim to the correct level. The I/P lamps are located in the following components:
• | Driver Information Center DIC switch |
• | Rear Seat Audio if equipped |
• | Rear HVAC Control if equipped |
• | Steering Wheel Controls |
• | Universal garage door opener switch |
Conditions for Running the DTC
The ignition is ON.
Conditions for Setting the DTC
B3600 03
The BCM detects a voltage that is lower then 5 volts on the I/P dimming control circuit.
B3600 07
The BCM detects a voltage that is higher then 5 volts on the I/P dimming control circuit.
Action Taken When the DTC Sets
The I/P lamps are not illuminated.
Conditions for Clearing the DTC
The BCM clears this code from current when the fault is removed from the system.
Reference Information
Schematic Reference
Interior Lights Dimming Schematics
Connector End View Reference
Lighting Systems Connector End Views
Electrical Information Reference
Scan Tool Reference
Circuit/System Verification
Ignition ON, cover the ambient light sensor, vary the interior lamp dimming switch from dim to full bright. The I/P lamps should dim and then become full bright.
Circuit/System Testing
- Clear the DTC. Disconnect the headlamp switch.
- Connect a DMM between the I/P dimming voltage reference circuit and the negative terminal of the battery.
- Ignition ON, test for 9-14 volts.
⇒ | If less then 9 volts, test the I/P dimming voltage reference circuit for a short to ground or an open/high resistance. If the circuit/connections test normal, replace the BCM. |
⇒ | If greater than 14 volts,
test the I/P dimming voltage reference circuit for a short to voltage. If the circuit/connections test normal, replace the BCM. |
- Disconnect the DMM. Install a jumper between I/P dimming voltage reference circuit and the I/P dimming control circuit.
- Verify that DTC B3600 03 does not set.
⇒ | If the DTC resets, then test for a short to ground in the I/P dimming control circuit. If the circuit/connections test normal, replace the BCM. |
- If all circuits/connections test normal, replace the turn signal multi function switch.
Repair Instructions
Perform the
Diagnostic Repair Verification
after completing the diagnostic procedure.