| Diagnosis and Testing Special Tool(s) | | 73III Automotive Meter 105-R0057 or equivalent | | | Vehicle Communication Module (VCM) and Integrated Diagnostic System (IDS) software with appropriate hardware, or equivalent scan tool | | | Flex Probe Kit 105-R025C or equivalent | Principles of Operation The instrument cluster sends a signal to the instrument panel dimmer switch. The instrument cluster provides a variable pulse width modulated (PWM) signal to the dimmable backlighting components based on the position of the instrument panel dimmer switch. Inspection and Verification - Verify the customer concern.
- Visually inspect the following for obvious signs of mechanical or electrical damage.
Visual Inspection Chart | Mechanical | Electrical | - Instrument panel dimmer switch
| - Smart junction box (SJB) fuse(s):
- Circuitry
- Illumination bulbs
- Instrument cluster
- SJB
| - If an obvious cause for an observed or reported concern is found, correct the cause (if possible) before proceeding to the next step.
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NOTE:Make sure to use the latest scan tool release software. If the cause is not visually evident, connect the scan tool to the data link connector (DLC). -
NOTE:The vehicle communication module (VCM) LED prove-out confirms power and ground from the DLC are provided to the VCM. If the scan tool does not communicate with the VCM: - Check the VCM connection to the vehicle.
- Check the scan tool connection to the VCM.
- If the scan tool does not communicate with the vehicle:
- Verify the ignition key is in the ON position.
- Verify the scan tool operation with a known good vehicle.
- Carry out the network test.
- If the network test passes, retrieve and record the continuous memory DTCs.
- Clear the continuous DTCs and carry out the self-test diagnostics for the instrument cluster.
- If no DTCs related to the concern are retrieved, GO to Symptom Chart.
Instrument Cluster Diagnostic Trouble Code (DTC) Index Symptom Chart Symptom Chart | Symptom | Possible Sources | Action | | One or more module-controlled illumination source(s) is inoperative | * Circuitry * Inoperative illumination source component | * | | The window control switch illumination is inoperative | * Window control switch | * VERIFY that the window control switch operates correctly. - If the window control switch operates correctly, INSTALL a new window control switch. REFER to Section 501-11 Glass, Frames and Mechanisms. TEST the system for normal operation. - | | The driver door lock control switch illumination is inoperative | * Driver door lock control switch | * | | The control illumination is inoperative | * Circuitry * Instrument cluster * Smart junction box (SJB) | * | | The instrument cluster illumination is inoperative | * Instrument cluster | * | | The climate control panel illumination is inoperative | * Circuitry * Climate control assembly | * | | The audio system illumination is inoperative | * Circuitry * Audio unit | * | | The instrument panel illumination does not dim | * Circuitry * Instrument panel dimmer switch * Instrument cluster | * | | The passenger door lock control switch illumination is inoperative | * Circuitry * Passenger door lock control switch | * | Pinpoint Tests Pinpoint Test A: One or More Module-Controlled Illumination Source(s) Is Inoperative Refer to Wiring Diagrams Cell 71, for schematic and connector information. Normal Operation The instrument panel dimmer switch provides an input to the instrument cluster through circuit 1011 (TN/OG). The instrument panel dimmer switch is grounded through circuit 570 (BK/WH). The instrument cluster monitors the medium-speed controller area network (MS-CAN) bus on circuits 1848 (PK/OG) and 1847 (WH/OG) for a PARKING LAMPS ON or HEADLAMPS ON message. The PARKING LAMPS ON or HEADLAMPS ON message is generated by the smart junction box (SJB). When the instrument cluster detects a HEADLAMPS ON message, it sends a pulse width modulated (PWM) voltage to the module-controlled illumination sources through circuit 19 (LB/RD). The module-controlled and non-dimmable illumination sources are grounded through circuits 57 (BK) and 570 (BK/WH). Possible Causes - Circuit 19 (LB/RD) open
- Circuit 57 (BK) open
- Rear window defrost switch
- Hazard flasher switch
- Transmission range selector
- Front fog lamp switch (if equipped)
- Rear fog lamp switch (if equipped)
| PINPOINT TEST A : ONE OR MORE MODULE-CONTROLLED ILLUMINATION SOURCE(S) IS INOPERATIVE | CAUTION:Use the correct probe adaptor(s) when making measurements. Failure to use the correct probe adaptor(s) may damage the connector. | | TEST CONDITIONS | DETAILS/RESULTS/ACTIONS | | A1: CHECK THE INSTRUMENT PANEL ILLUMINATION OPERATION | | | 1 Ignition switch in position II. | | | 2 Place the headlamp switch in the PARKING LAMPS ON position. | | | 3 Press the instrument panel dimmer switch to the full illumination position. | | | Are all the illumination sources inoperative? Yes GO to Pinpoint Test B. to continue diagnosis of the backlighting system. No TURN the headlamp switch off. GO to A2. . | | A2: CHECK VOLTAGE TO THE INOPERATIVE ILLUMINATION SOURCE | | | 1 Ignition switch in position 0. | | | 2 Disconnect Inoperative Illumination Source Connector. | | | 3 Ignition switch in position II. | | | 4 Place the headlamp switch in the PARKING LAMPS ON position. | | | 5 Measure the voltage between the inoperative illumination source, harness side and ground according to the following table: | Illumination Source | Connector- Pin | Circuit | | Rear window defrost switch | C2340-3 | 19 (LB/RD) | | Hazard flasher switch | C2039-8 | 19 (LB/RD) | | Transmission range selector | C2096-4 | 19 (LB/RD) | | Front fog lamp switch | C2341-3 | 19 (LB/RD) | | Rear fog lamp switch | C2343-3 | 19 (LB/RD) | | | | Is the voltage greater than 10 volts? Yes TURN the headlamp switch off. GO to A3. . No REPAIR the circuit in question. TEST the system for normal operation. | | A3: CHECK THE GROUND TO THE INOPERATIVE ILLUMINATION SOURCE | | | 1 Ignition switch in position 0. | | | 2 Measure the resistance between the inoperative illumination source, harness side and ground according to the following table: | Illumination Source | Connector- Pin | Circuit | | Rear window defrost switch | C2340-5 | 57 (BK) | | Hazard flasher switch | C2039-4 | 57 (BK) | | Transmission range selector | C2096-1 | 57 (BK) | | Front fog lamp switch | C2341-5 | 57 (BK) | | Rear fog lamp switch | C2343-5 | 57 (BK) | | | | Is the resistance less than 5 ohms? Yes INSTALL a new illumination source as necessary. TEST the system for normal operation. No REPAIR the circuit. TEST the system for normal operation. | Pinpoint Test B: The Control Illumination Is Inoperative Refer to Wiring Diagrams Cell 71, for schematic and connector information. Normal Operation The instrument cluster monitors the medium-speed controller area network (MS-CAN) bus on circuits 1848 (PK/OG) and 1847 (WH/OG) for a PARKING LAMPS ON or HEADLAMPS ON message. The PARKING LAMPS ON or HEADLAMPS ON message is generated by the smart junction box (SJB). When the instrument cluster detects a HEADLAMPS ON message, it sends a variable voltage to the module-controlled illumination sources through circuit 19 (LB/RD). The module-controlled illumination sources are grounded through circuit 57 (BK). Possible Causes - Circuit 19 (LB/RD) open, short to ground or voltage
- Circuit 170 (RD/LB) short to voltage
- Instrument cluster
- SJB
| PINPOINT TEST B : THE CONTROL ILLUMINATION IS INOPERATIVE | CAUTION:Use the correct probe adaptor(s) when making measurements. Failure to use the correct probe adaptor(s) may damage the connector. | | TEST CONDITIONS | DETAILS/RESULTS/ACTIONS | | B1: CHECK THE DOOR LOCK CONTROL SWITCH ILLUMINATION | | | 1 Ignition switch in position 0. | | | 2 Open the driver front door. | | | 3 Observe the door lock control switch. | | | Is the door lock control switch illuminated? Yes No | | B2: CHECK CIRCUIT 170 (RD/LB) FOR A SHORT TO VOLTAGE | | | 1 Disconnect SJB . | | | 2 Observe the door lock control switch. | | | Is the door lock control switch illuminated? Yes REPAIR the circuit. TEST the system for normal operation. No | | B3: CHECK THE DIMMABLE BACKLIGHTING COMPONENTS | | | 1 Ignition switch in position II. | | | 2 Observe all the dimmable backlighting components. | | | Are all the dimmable backlighting components illuminated? Yes No | | B4: CHECK CIRCUIT 19 (LB/RD) FOR AN OPEN | | | 1 Ignition switch in position 0. | | | 2 Disconnect Instrument Cluster . | | | NOTE:If the fuse fails, repair the circuit for a short to ground. 3 Connect a fused (5A) jumper wire between the instrument cluster C220-26, circuit 19 (LB/RD), harness side and the instrument cluster C220-28, circuit 1002 (BK/PK), harness side. | | | 4 Ignition switch in position II. | | | Do the illumination components illuminate? Yes No REPAIR the circuit. TEST the system for normal operation. | | B5: CHECK CIRCUIT 19 (LB/RD) FOR A SHORT TO VOLTAGE | | | 1 Disconnect Instrument Cluster . | | | 2 Observe all the dimmable backlighting components. | | | Are all the dimmable backlighting components illuminated? Yes REPAIR the circuit. TEST the system for normal operation. No | | B6: CHECK FOR CORRECT INSTRUMENT CLUSTER OPERATION | | | 1 Disconnect all the instrument cluster connectors. | | | 2 Check for: | | | 3 Connect all the instrument cluster connectors and make sure they seat correctly. | | | 4 Operate the system and verify the concern is still present. | | | Is the concern still present? Yes 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. | | B7: CHECK FOR CORRECT SJB OPERATION | | | 1 Disconnect all the SJB connectors. | | | 2 Check for: | | | 3 Connect all the SJB connectors and make sure they seat correctly. | | | 4 Operate the system and verify the concern is still present. | | | Is the concern still present? Yes 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. | Pinpoint Test C: The Climate Control Panel Illumination Is Inoperative Refer to Wiring Diagrams Cell 71, for schematic and connector information. Normal Operation When the instrument cluster detects a PARKING LAMPS ON or HEADLAMPS ON message, it sends a pulse width modulated (PWM) voltage to the climate control assembly through circuit 19 (LB/RD). The climate control assembly is grounded through circuit 57 (BK). Possible Causes - Circuit 19 (LB/RD) open
- Circuit 57 (BK) open
- Climate control assembly
| PINPOINT TEST C : THE CLIMATE CONTROL PANEL ILLUMINATION IS INOPERATIVE | CAUTION:Use the correct probe adaptor(s) when making measurements. Failure to use the correct probe adaptor(s) may damage the connector. | | TEST CONDITIONS | DETAILS/RESULTS/ACTIONS | | C1: CHECK FOR VOLTAGE ON CIRCUIT 19 (LB/RD) | | | 1 Ignition switch in position 0. | | | 2 Disconnect Climate Control Assembly . | | | 3 Place the headlamp switch in the PARK position. | | | 4 Move the instrument panel dimmer switch to the full illumination position. | | | 5 Measure the voltage between the climate control assembly C294c-2, circuit 19 (LB/RD), harness side and ground. | | | Is the voltage greater than 10 volts? Yes No REPAIR the circuit. TEST the system for normal operation. | | C2: CHECK CIRCUIT 57 (BK) FOR AN OPEN | | | 1 Measure the resistance between the climate control assembly C294c-1, circuit 57 (BK), harness side and ground. | | | Is the resistance less than 5 ohms? Yes No REPAIR the circuit. TEST the system for normal operation. | Pinpoint Test D: The Audio System Illumination Is Inoperative Refer to Wiring Diagrams Cell 71, for schematic and connector information. Normal Operation When the instrument cluster detects a PARKING LAMPS ON or HEADLAMPS ON message, it sends a pulse width modulated (PWM) voltage to the audio unit through circuit 19 (LB/RD). The audio unit is grounded through circuit 57 (BK). Possible Causes - Circuit 19 (LB/RD) open
- Circuit 57 (BK) open
- Audio unit
| PINPOINT TEST D : THE AUDIO SYSTEM ILLUMINATION IS INOPERATIVE | CAUTION:Use the correct probe adaptor(s) when making measurements. Failure to use the correct probe adaptor(s) may damage the connector. | | TEST CONDITIONS | DETAILS/RESULTS/ACTIONS | | D1: VERIFY THE AUDIO UNIT ILLUMINATION | | | 1 Place the headlamp switch in the PARK position. | | | 2 Press the instrument panel dimmer switch to the full illumination position. | | | Does all the illumination operate correctly? Yes System is OK. No For all others or a individual illumination sourceGO to Pinpoint Test B. . | | D2: CHECK FOR VOLTAGE ON CIRCUIT 19 (LB/RD) | | | 1 Ignition switch in position 0. | | | 2 Disconnect Audio Unit . | | | 3 Measure the voltage between the audio unit C290a-4, circuit 19 (LB/RD), harness side and ground. | | | Is the voltage greater than 10 volts? Yes No REPAIR the circuit. TEST the system for normal operation. | | D3: CHECK CIRCUIT 57 (BK) FOR AN OPEN | | | 1 Measure the resistance between the audio unit C290a-2, circuit 57 (BK), harness side and ground. | | | Is the resistance less than 5 ohms? Yes INSTALL a new audio unit. REFER to Section 415-01 Audio Unit. TEST the system for normal operation. No REPAIR the circuit. TEST the system for normal operation. | Pinpoint Test E: The Instrument Panel Illumination Does Not Dim Refer to Wiring Diagrams Cell 71, for schematic and connector information. Normal Operation The instrument panel dimmer switch is an input to the instrument cluster through circuit 1011 (TN/OG). The instrument panel dimmer switch is grounded through circuit 570 (BK/WH). DTC B1246 — sets in the instrument cluster on-demand when an open or short to ground is detected on circuit 1011 (TN/OG). Possible Causes - Circuit 1011 (TN/OG) open or short to ground
- Circuit 570 (BK/WH) open
- Instrument panel dimmer switch
- Instrument cluster
| PINPOINT TEST E : THE INSTRUMENT PANEL ILLUMINATION DOES NOT DIM | CAUTION:Use the correct probe adaptor(s) when making measurements. Failure to use the correct probe adaptor(s) may damage the connector. | | TEST CONDITIONS | DETAILS/RESULTS/ACTIONS | | E1: CHECK THE RECORDED INSTRUMENT CLUSTER DTCS | | | 1 Check the recorded results from the instrument cluster self-test. | | | Are any DTCs present? Yes For DTC B1246, GO to E2. .For all other DTCs, REFER to the Instrument Cluster Diagnostic Trouble Code (DTC) Index. No | | E2: CHECK CIRCUIT 1011 (TN/OG) FOR A SHORT TO GROUND | | | 1 Ignition switch in position 0. | | | 2 Disconnect Instrument Cluster . | | | 3 Measure the resistance between the instrument cluster C220-23, circuit 1011 (TN/OG), harness side and ground. | | | Is the resistance greater than 10,000 ohms? Yes INSTALL a new instrument panel dimmer switch. CLEAR the DTC. REPEAT the self-test. No REPAIR the circuit. CLEAR the DTC. REPEAT the self-test. | | E3: CHECK CIRCUIT 570 (BK/WH) FOR AN OPEN | | | 1 Ignition switch in position 0. | | | 2 Disconnect Instrument Panel Dimmer Switch . | | | 3 Measure the resistance between the instrument panel dimmer switch C2065-5, circuit 570 (BK/WH), harness side and ground. | | | Is the resistance less than 5 ohms? Yes No REPAIR the circuit. TEST the system for normal operation. | | E4: CHECK THE INSTRUMENT PANEL DIMMER SWITCH | | | 1 Carry out the instrument panel dimmer switch component test. Refer to Wiring Diagrams Cell 149, for schematic and connector information. | | | Is the instrument panel dimmer switch OK? Yes No INSTALL a new instrument panel dimmer switch. TEST system for normal operation. | | E5: CHECK CIRCUIT 1011 (TN/OG) FOR AN OPEN | | | 1 Disconnect Instrument Cluster . | | | 2 Measure the resistance between the instrument cluster C220-23, circuit 1011 (TN/OG), harness side and the instrument panel dimmer switch C2065-3, circuit 1011 (TN/OG), harness side. | | | Is the resistance less than 5 ohms? Yes No REPAIR the circuit. TEST the system for normal operation. | | E6: CHECK FOR CORRECT INSTRUMENT CLUSTER OPERATION | | | 1 Disconnect the instrument cluster connector. | | | 2 Check for: | | | 3 Connect the instrument cluster connector and make sure it seats correctly. | | | 4 Operate the system and verify the concern is still present. | | | Is the concern still present? Yes 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. | Pinpoint Test F: The Passenger Door Lock Control Switch Illumination Is Inoperative Refer to Wiring Diagrams Cell 110, for schematic and connector information. Normal Operation When the instrument cluster detects a PARKING LAMPS ON or HEADLAMPS ON message, it sends voltage to the passenger door lock control switch assembly through circuit 170 (RD/LB). The passenger door lock control switch assembly is grounded through circuit 570 (BK/WH). Possible Causes - Circuit 170 (RD/LB) open
- Circuit 570 (BK/WH) open
- Passenger door lock control switch
| PINPOINT TEST F : THE PASSENGER DOOR LOCK CONTROL SWITCH ILLUMINATION IS INOPERATIVE | | TEST CONDITIONS | DETAILS/RESULTS/ACTIONS | | F1: CHECK FOR VOLTAGE ON CIRCUIT 170 (RD/LB) | | | 1 Ignition switch in position 0. | | | 2 Disconnect Passenger Door Lock Control Switch . | | | 3 Place the headlamp switch in the PARKING LAMPS ON position. | | | 4 Move the instrument panel dimmer switch to the full illumination position. | | | 5 Measure the voltage between the passenger door lock control switch C605-5, circuit 170 (RD/LB), harness side and ground. | | | Is the voltage greater than 10 volts? Yes No REPAIR the circuit. TEST the system for normal operation. | | F2: CHECK CIRCUIT 57 (BK) FOR AN OPEN | | | 1 Measure the resistance between the passenger door lock control switch C605-1, circuit 570 (BK/WH), harness side and ground. | | | Is the resistance less than 5 ohms? Yes No REPAIR the circuit. TEST the system for normal operation. | |
