Pinpoint Test D: All Dimmable Illumination Does Not Dim
Instrument Cluster and Panel Illumination
Pinpoint Tests
Pinpoint Test D: All Dimmable Illumination Does Not Dim
Refer to Wiring Diagram Set 71, Cluster and Panel Illumination for schematic and connector information. Diagrams By Number
NOTE: Calibrate the instrument panel dimmer switch by rotating the dimmer switch from the lowest backlighting setting to the DOME LAMP position before continuing diagnostics.
Normal Operation
The Smart Junction Box (SJB) sends a voltage signal to the instrument panel dimmer switch. The signal is routed through a variable resistor within the instrument panel dimmer switch and then back to the SJB to an internal ground. The voltage signal changes depending on the position of the dimmer switch. When the dimmer switch is in the lowest setting, the resistance is low. When the SJB senses the voltage signal is low (switch in the lowest setting), the dimmable backlighting intensity is low. When the SJB senses the voltage signal is high (switch in the highest setting), the dimmable backlighting intensity is bright. If the signal is too high (an open circuit or short to voltage), the SJB faults the dimmable backlighting to full nighttime brightness. If the dimmer switch monitoring circuit is short to ground, the SJB interprets this as the lowest setting and sets the backlighting to the lowest intensity level, appearing to be inoperative.
- DTC B2212 (Panel Dim Switch Out of Range) - is an on-demand DTC that sets when the SJB detects an open or short to voltage from the dimmer switch input switch circuit.
This pinpoint test is intended to diagnose the following:
- Wiring, terminals or connectors
- Instrument panel dimmer switch
- SJB
PINPOINT TEST D: ALL DIMMABLE ILLUMINATION DOES NOT DIM
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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D1 CHECK THE INSTRUMENT PANEL DIMMER SWITCH
- Ignition OFF.
- Disconnect: Instrument Panel Dimmer Switch C2065.
- Carry out the component test for the instrument panel dimmer switch.
Refer to Wiring Diagrams for component testing. Diagrams By Number
- Is the instrument panel dimmer switch OK?
Yes
GO to D2.
No
INSTALL a new instrument panel dimmer switch. REFER to Instrument Panel Dimmer Switch Service and Repair. CLEAR the DTCs. REPEAT the self-test.
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D2 CHECK THE INSTRUMENT PANEL DIMMER SWITCH INPUT CIRCUIT FOR A SHORT TO VOLTAGE
- Disconnect: SJB C2280d.
- Ignition ON.
- Measure the voltage between the instrument panel dimmer switch C2065-6, circuit CLN27 (WH/BN), harness side and ground.
- Is any voltage present?
Yes
REPAIR circuit CLN27 (WH/BN) for a short to voltage. CLEAR the DTCs. REPEAT the self-test.
No
GO to D3.
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D3 CHECK THE INSTRUMENT PANEL DIMMER SWITCH RETURN CIRCUIT FOR A SHORT TO VOLTAGE
- Measure the voltage between the instrument panel dimmer switch C2065-4, circuit RLN29 (WH/OG), harness side and ground.
- Is any voltage present?
Yes
REPAIR circuit RLN29 (WH/OG) for a short to voltage. CLEAR the DTCs. REPEAT the self-test.
No
GO to D4.
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D4 CHECK THE INSTRUMENT PANEL DIMMER SWITCH INPUT CIRCUIT FOR AN OPEN
- Ignition OFF.
- Measure the resistance between the instrument panel dimmer switch C2065-6, circuit CLN27 (WH/BN), harness side and the SJB C2280b-34, circuit CLN27 (WH/BN), harness side.
- Is the resistance less than 5 ohms?
Yes
GO to D5.
No
REPAIR circuit CLN27 (WH/BN) for an open. CLEAR the DTCs. REPEAT the self-test.
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D5 CHECK THE INSTRUMENT PANEL DIMMER SWITCH RETURN CIRCUIT FOR AN OPEN
- Measure the resistance between the instrument panel dimmer switch C2065-4, circuit RLN29 (WH/OG), harness side and the SJB C2280b-33, circuit RLN29 (WH/OG), harness side.
- Is the resistance less than 5 ohms?
Yes
GO to D6.
No
REPAIR circuit RLN29 (WH/OG) for an open. CLEAR the DTCs. REPEAT the self-test.
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D6 CHECK THE INSTRUMENT PANEL DIMMER SWITCH INPUT CIRCUIT FOR A SHORT TO GROUND
- Ignition OFF.
- Measure the resistance between the instrument panel dimmer switch C2065-6, circuit CLN27 (WH/BN), harness side and ground.
- Is the resistance greater than 10,000 ohms?
Yes
GO to D7.
No
REPAIR circuit CLN27 (WH/BN) for a short to ground. TEST the system for normal operation.
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D7 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. CLEAR the DTCs. REPEAT the self-test.
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