Diagnostic Instructions
| • | 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. |
DTC Descriptors
DTC B1395 03 : Voltage Below ThresholdDTC B1395 07 : Voltage Above Threshold
Diagnostic Fault Information
Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance |
|---|---|---|---|---|
DIM Fuse B+ | 2 | 2 | -- | -- |
I/P Dimmer Voltage Reference | B1395 03 and B3600 03 | B1395 03, B2652 00, and B3600 03 | B1395 07 | -- |
IS LPS Fuse B+ | 2 | 2 | -- | -- |
I/P DImmer Switch Signal | B1395 03 | 2 | 2 | -- |
Stop Lamp Switch Signal | B1395 03 and B3600 03 | 3 | 3 | -- |
I/P Dimming Control | B2625 00 and B2652 00 | 2 | 2 | -- |
LED DImming Supply | B2610 00 and, B2625 00 | B2610 00 | B2610 00 | -- |
Park Lamp Control | 2 | 2 | 2 | -- |
Indicator Dimming Low Reference | 2 | 2 | 2 | -- |
I/P Dimmer Switch Low Reference | -- | 1 | -- | -- |
I/P Dimmer Switch Ground | -- | 2 | -- | -- |
1. Dimmer Switch Malfunction 2. Interior Backlighting Malfunction 3. Stop Lamp Switch Malfunction | ||||
Circuit/System Description
The instrument panel (I/P) lamp dimmer switch is used to increase and decrease the brightness of the interior backlighting components. The I/P dimmer switch provides a voltage signal that will increase as the brightness of the lights are increased, and decrease as the brightness of the lights are decreased. The body control module (BCM) provides a low reference signal and a B+ voltage reference to the I/P dimmer switch. When the I/P dimmer switch is placed in the desired position, the dimmed voltage setting is applied from the I/P dimmer switch through the I/P dimmer switch signal circuit to the BCM. The BCM interprets the signal and applies the dimmed voltage to the I/P lamps supply voltage circuit and the interior backlighting components dim to the requested level. Ground for the I/P dimmer switch is provided at G200
Conditions for Running the DTC
Battery voltage must be between 9-16 volts.
Conditions for Setting the DTC
B1395 03
| • | The BCM detects a short to ground in the I/P dimmer switch voltage reference circuit. |
| • | The BCM detects a short to ground in the I/P dimmer switch signal circuit. |
| • | The BCM detects a short to ground or an open/high resistance in the IS LPS fused B+ circuit. |
B1395 07
The DTC will set when the BCM detects a short to voltage in the I/P dimming voltage reference circuit or the vehicles system voltage exceeds the normal operating range of 16 volts.
Action Taken When the DTC Sets
| • | The I/P lamps are dim or not illuminated. |
| • | The I/P lamps will not dim. |
Conditions for Clearing the DTC
| • | The conditions for setting the DTC are no longer present. |
| • | A history DTC clears after 100 malfunction-free ignition cycles. |
| • | The BCM receives the clear code command from the scan tool. |
Reference Information
Schematic Reference
Connector End View Reference
Description and Operation
Interior Lighting Systems Description and Operation
Electrical Information Reference
Scan Tool Reference
Control Module References for scan tool information
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
- Ignition OFF, disconnect the harness connector at the headlamp and panel dimmer switch.
- Ignition OFF, verify that a test lamp illuminates between the ground circuit terminal 8 and B+.
- Ignition ON, verify the scan tool Dimming Control Signal parameter is less than 0.1 volts.
- Ignition ON, test for B+ between the I/P dimming voltage reference circuit terminal 15 and ground.
- Install a 3A fused jumper wire between the signal circuit terminal 13 and the voltage reference circuit terminal 15. Verify the scan tool BCM Dimming Control Signal parameter is greater than 2.6 volts.
- If all circuits test normal, test or replace the headlamp and panel dimmer switch.
| ⇒ | If the test lamp does not illuminate, test the ground circuit for an open/high resistance. |
| ⇒ | If greater than the specified range, test the signal circuit terminal 13 for a short to voltage. If the circuit tests normal, replace the BCM. |
| ⇒ | If the test lamp does not illuminate, test the voltage reference circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the BCM. |
| ⇒ | If less than the specified range, test the signal circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the BCM. |
Repair Instructions
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
| • | Control Module References for BCM replacement, setup, and programming |
