Pinpoint Test A: The Dimmable Illumination Does Not Dim
Instrument Cluster and Panel Illumination
Pinpoint Tests
Pinpoint Test A: The Dimmable Illumination Does Not Dim
Refer to Wiring Diagram Set 71, Cluster and Panel Illumination for schematic and connector information. Diagrams By Number
Normal Operation
The Lighting Control Module (LCM) supplies a Pulse Width Modulated (PWM) voltage to the instrument panel switches (except the HVAC module on vehicles with automatic temperature control and the Instrument Cluster (IC) which receive the brightness level from the LCM over the network). The LCM uses the instrument panel dimmer switch to determine the intensity of switch illumination.
- DTC B2212 (Panel Dim Switch Out of Range) - an on-demand DTC that sets when the SJBLCM detects an out of range condition on the dimmer input switch circuit.
This pinpoint test is intended to diagnose the following:
- Wiring, terminals or connectors
- Instrument panel dimmer switch
- LCM
PINPOINT TEST A: THE 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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A1 CHECK DTCs FROM THE LCM
- Check the recorded results from the LCM self-test.
- Is DTC B2212 recorded?
Yes
GO to A2.
No
GO to A6.
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A2 CHECK THE INSTRUMENT PANEL DIMMER SWITCH SIGNAL CIRCUIT FOR A SHORT TO VOLTAGE
- Ignition OFF.
- Disconnect: LCM C2145a.
- Ignition ON.
- Measure the voltage between the LCM C2145a-7, circuit 1036 (BN/WH), harness side and ground.
- Is any voltage present?
Yes
REPAIR circuit 1036 (BN/WH) for a short to voltage. TEST the system for normal operation.
No
GO to A3.
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A3 VERIFY DTC B2212
- Disconnect: Negative Battery Cable.
- Ignition OFF.
- While rotating the instrument panel dimmer switch wheel from the maximum setting to the minimum setting, measure the resistance between the LCM C2145a-7, circuit 1036 (BN/WH), harness side and ground.
- Does the resistance vary between 545 ohms and 25 ohms?
Yes
GO to A7.
No
GO to A4.
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A4 CHECK THE INSTRUMENT PANEL DIMMER SWITCH SIGNAL CIRCUIT FOR AN OPEN OR SHORT TO GROUND
- Disconnect: Instrument Panel Dimmer Switch C205b.
- Measure the resistance between the LCM C2145a-7, circuit 1036 (BN/WH), harness side and the instrument panel dimmer switch C205b-6, circuit 1036 (BN/WH), harness side; and between the LCM C2145a-7, circuit 1036 (BN/WH), harness side and ground.
- Is the resistance less than 5 ohms between the LCM and the instrument panel dimmer switch, and greater than 10,000 ohms between the LCM and ground?
Yes
GO to A5.
No
REPAIR circuit 1036 (BN/WH) for an open or short to ground. TEST the system for normal operation.
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A5 CHECK INSTRUMENT PANEL DIMMER SWITCH GROUND CIRCUIT FOR AN OPEN
- Measure the resistance between the instrument panel dimmer switch C205b-4, circuit 57 (BK), harness side and ground.
- Is the resistance less than 5 ohms?
Yes
INSTALL a new instrument panel dimmer switch. REFER to Instrument Panel Dimmer Switch Service and Repair. TEST the system for normal operation.
No
REPAIR circuit 57 (BK) for an open. TEST the system for normal operation.
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A6 CHECK THE LCM DIMMABLE OUTPUT CIRCUIT FOR A SHORT TO VOLTAGE
- Ignition OFF.
- Disconnect: LCM C2145c.
- Ignition ON.
- Measure the voltage between the LCM C2145c-3, circuit 484 (OG/BK), harness side and ground.
- Is any voltage present?
Yes
REPAIR circuit 484 (OG/BK) for a short to voltage. TEST the system for normal operation.
No
GO to A7.
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A7 CHECK FOR CORRECT LCM OPERATION
- Ignition OFF.
- Disconnect all the LCM connectors.
- Check for:
- corrosion
- damaged pins
- pushed-out pins
- Connect all the LCM 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 LCM. 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.
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