Pinpoint Test B: The Courtesy Lamps Do Not Illuminate From The Instrument Panel Dimmer Switch
Interior Lighting
Pinpoint Test B: The Courtesy Lamps Do Not Illuminate From The Instrument Panel Dimmer Switch
Refer to Wiring Diagram Set 89 (Fusion/Milan/MKZ, Fusion Hybrid, Milan Hybrid, MKZ Hybrid), Interior Lamps for schematic and connector information. Diagrams By Number
Normal Operation
The Smart Junction Box (SJB) turns the courtesy lamps on and off by monitoring the dimmer switch input and the dome lamp request input circuits. When the instrument panel dimmer switch is pushed to the second detent up, the backlighting dim up circuit and the dome request circuit are both requested to indicate a request to turn the courtesy lamps on. When the instrument panel dimmer switch is pushed to the second detent down, the backlighting dim down circuit and the dome request circuit are both requested to indicate a request to turn the courtesy lamps off.
This pinpoint test is intended to diagnose the following:
- Wiring, terminals or connectors
- Instrument panel dimmer switch
- SJB
PINPOINT TEST B: THE COURTESY LAMPS DO NOT ILLUMINATE FROM THE INSTRUMENT PANEL DIMMER SWITCH
NOTICE: Use the correct probe adapter(s) when making measurements. Failure to use the correct probe adapter(s) may damage the connector.
-------------------------------------------------
B1 CHECK THE DIMMABLE BACKLIGHTING ILLUMINATION
- Ignition OFF.
- Turn the headlamps switch to the PARKING LAMPS ON position.
- Monitor the instrument panel dimmable backlighting while pushing the instrument panel dimmer switch from full on to full off.
- Does the instrument cluster illumination intensity change with the instrument panel dimmer switch position?
Yes
GO to B2.
No
REFER to Instrument Cluster and Panel Illumination Testing and Inspection to continue diagnosis of the dimmable backlighting illumination.
-------------------------------------------------
B2 CHECK THE INSTRUMENT PANEL DIMMER SWITCH
- Turn the headlamps switch to the OFF position.
- Disconnect: Instrument Panel Dimmer Switch C2065 .
- Measure the voltage between the instrument panel dimmer switch C2065-2, circuit CLN28 (GN/BU), harness side and ground.
- Is the voltage greater than 10 volts?
Yes
INSTALL a new instrument panel dimmer switch. REFER to Instrument Cluster and Panel Illumination Service and Repair.
TEST the system for normal operation.
No
GO to B3.
-------------------------------------------------
B3 CHECK THE DOME LAMP REQUEST INPUT CIRCUIT FOR AN OPEN
- Disconnect: SJB C2280b .
- Measure the resistance between the SJB C2280b-51, circuit CLN28 (GN/BU), harness side and the instrument panel dimmer switch C2065-2, circuit CLN28 (GN/BU), harness side.
- Is the resistance less than 5 ohms?
Yes
GO to B4.
No
REPAIR the circuit. TEST the system for normal operation.
-------------------------------------------------
B4 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?
Yes
INSTALL a new SJB. REFER to Multifunction Electronic Modules Service and Repair. TEST the system for normal operation.
No
The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector.
-------------------------------------------------