Pinpoint Test F: One Or More Switch Illumination Is Inoperative
Instrument Cluster and Panel Illumination
Pinpoint Tests
Pinpoint Test F: One Or More Switch Illumination Is Inoperative
Refer to Wiring Diagram Set 71, Cluster and Panel Illumination for schematic and connector information. Diagrams By Number
Normal Operation
The Smart Junction Box (SJB) sends a pulse-width modulated voltage to the dimmable components for illumination. The SJB also controls the accessory delay relay. The accessory delay relay provides battery voltage to the door lock and roof opening panel control switches.
- DTC B2026 (Incandescent Backlighting Output Circuit Failure) - a continuous and on-demand DTC that may set if the SJB detects a short to ground from the illumination supply circuit.
- DTC B2027 (LED Backlighting Output Circuit Failure) - a continuous and on-demand DTC that may set if the SJB detects a short to ground from the illumination supply circuit.
This pinpoint test is intended to diagnose the following:
- Wiring, terminals or connectors
- Four-Wheel Drive (4WD) mode select switch
- Memory set switch (if equipped)
- HVAC module
- Heated seat switch (if equipped)
- Auxiliary climate control switches (if equipped)
- Adjustable pedal switch (if equipped)
- Message center switch (if equipped)
- Traction control switch (if equipped)
- Headlamp switch
- Floor shifter
- Door lock control switch
- Roof opening panel control switch (overhead console)
- SJB
PINPOINT TEST F: ONE OR MORE SWITCH ILLUMINATION IS INOPERATIVE
NOTICE: Use the correct probe adapter(s) when making measurements. Failure to use the correct probe adapter(s) may damage the connector.
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F1 CHECK THE ILLUMINATION SOURCE(S) OPERATION
- Place the headlamp switch in the PARKING LAMPS ON position and turn the dimmer switch to the full illumination position.
- Is only one illumination source inoperative?
Yes
GO to F3.
No
GO to F2.
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F2 BYPASS THE SJB
NOTE: If the jumper wire fuse fails, refer to the Wiring Diagrams to identify the possible causes of the circuit short. Diagrams By Number
- Ignition OFF.
- Disconnect: SJB C2280a (Door Lock Control Switches).
- Disconnect: SJB C2280c (Dimmable Components).
- If both door lock control switch illumination are inoperative, connect a fused jumper wire between the SJB C2280a-9, circuit CBP05 (YE), harness side and battery positive.
- If the floor shifter and headlamp switch illumination is inoperative, connect a fused jumper wire between the SJB C2280c-10, circuit CLN04 (BU/BN), harness side and battery positive.
- If all other instrument panel switch illumination is inoperative, connect a fused jumper wire between the SJB C2280c-28, circuit CLN04 (BU/BN), harness side and battery positive.
- Do the components in question illuminate?
Yes
REMOVE the jumper wire. GO to F5.
No
REMOVE the jumper wire.
REPAIR circuit CLN04 (BU/BN) (dimmable illumination) or circuit CBP05 (YE) (fixed illumination) for an open. TEST the system for normal operation.
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F3 CHECK FOR VOLTAGE TO THE SINGLE ILLUMINATION SOURCE
NOTE: If the headlamp switch is the inoperative source, unplug the headlamp switch connector to measure the illumination circuit voltage. Unplugging the connector causes the SJB to turn the exterior lights on by default for 10 minutes, so it is unnecessary to turn the headlamp switch on.
- Ignition OFF.
- Disconnect: Inoperative Illumination Source.
- Place the headlamp switch to the PARKING LAMPS ON position.
- Rotate the instrument panel dimmer switch to the full illumination position.
- Measure the voltage between the inoperative illumination source, harness side and ground as follows:
- Is the voltage greater than 10 volts?
Yes
GO to F4.
No
REPAIR circuit CLN04 (BU/BN) (dimmable illumination) or circuit CBP05 (YE) (fixed illumination) for an open. TEST the system for normal operation.
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F4 CHECK FOR VOLTAGE TO THE SINGLE ILLUMINATION SOURCE USING THE CONNECTOR GROUND
- Measure the voltage between the inoperative illumination source, harness side as follows:
- Is the resistance less than 5 ohms?
Yes
INSTALL a new component in question. TEST the system for normal operation.
No
REPAIR the ground circuit in question. TEST the system for normal operation.
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F5 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 Body Control Systems. 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.
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