Pinpoint Test B: The Control Illumination Is Always On - All Hardwired Illumination

Refer to appropriate SYSTEM WIRING DIAGRAM article for Cluster and Panel Illumination schematic and connector information.

Normal Operation

The smart junction box (SJB) supplies a pulse-width modulated (PWM) voltage signal to the dimmable illumination sources on circuit VLN04 (VT/GY) (Edge) and VLN37 (BU/WH) (MKX).

DTC B2A32 (LED Backlighting Output Circuit Open) - is an on-demand DTC that sets when the SJB detects a short to voltage on the LED backlighting output circuit.
DTC B29B7 (White Lighting Output Circuit Open) - is an on-demand DTC that sets when the SJB detects a short to voltage on the white lighting output circuit.

This pinpoint test is intended to diagnose the following:

Wiring, terminals or connectors
SJB

PINPOINT TEST B: THE CONTROL ILLUMINATION IS ALWAYS ON - ALL HARDWIRED ILLUMINATION

B1 CHECK THE EXTERIOR LIGHTING
- Key in OFF position.
- Place the headlamp switch in the OFF position.
- Observe the exterior lighting components.
- Key in ON position.
- Are any exterior lighting components illuminated?
1. YES : REFER to EXTERIOR LIGHTING article.
2. NO : Go to B2.
B2 CHECK CIRCUITS VLN04 (VT/GY) (EDGE) AND VLN37 (BU/WH) (MKX) FOR A SHORT TO VOLTAGE
- Disconnect: SJB C2280b
- Key in ON position.
- Do the dimmable backlighted components continue to illuminate?
1. YES : REPAIR the circuit in question. CLEAR the DTCs. REPEAT the self-test.
2. NO : Go to B3.
B3 CHECK FOR CORRECT SJB OPERATION
- Disconnect all the SJB connectors.
- Check for:
  - corrosion
  - damaged pins
  - pushed-out pins
- Connect all the SJB connectors and make sure they seat correctly.
- Operate the system and verify the concern is still present.
- Is the concern still present?
1. YES : INSTALL a new SJB. REFER to MULTIFUNCTION ELECTRONIC MODULES article. TEST the system for normal operation.
2. NO : The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector.