Pinpoint Test A: The Courtesy Lamps Are Inoperative
Interior Lighting
Pinpoint Tests
Pinpoint Test A: The Courtesy Lamps Are Inoperative
Refer to Wiring Diagram Set 89, Interior Lamps for schematic and connector information. Diagrams By Number
Normal Operation
Voltage is supplied to the Smart Junction Box (SJB) through the Bussed Electrical Center (BEC) fuse 67 (30A) to the SJB. The SJB monitors the dome lamp request and the ajar circuits. Based on the status, the SJB supplies voltage and ground to the courtesy lamps through circuits 53 (BK/LB) and 54 (LG/YE).
- DTC B2021 (Dome Lamp Output Return Circuit Failure) - a continuous and on-demand DTC that sets when the SJB detects a short to voltage on the dome lamp return circuit.
- DTC B2550 (Dome Lamp Output Circuit Short to Ground) - a continuous and on-demand DTC that sets when the SJB detects a short to ground on the dome lamp output supply circuit.
- DTC B2554 (Dome Lamp Output Circuit Failure) - a on-demand DTC that sets when the SJB detects an open on the dome lamp supply or return circuits.
This pinpoint test is intended to diagnose the following:
- Fuse
- Wiring, terminals or connectors
- Interior lamp
- SJB
PINPOINT TEST A: THE COURTESY LAMPS ARE 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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A1 CHECK THE RECORDED DTCs FROM THE SJB SELF-TEST
- Check the recorded results from the SJB self-test.
- Is DTC B2021, B2550 or B2554 present?
Yes
For DTC B2021, GO to A2.
For DTC B2550, GO to A4.
For DTC B2554, GO to A6.
No
GO to A10.
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A2 CHECK THE INTERIOR LAMP (DTC B2021)
- Ignition OFF.
- Disconnect: Overhead Console C930 (Without Convertible Top).
- Disconnect: Overhead Console C9013 (With Convertible Top).
- Ignition ON.
- Enter the following diagnostic mode on the scan tool: SJB Self-Test.
- NOTE: DTC B2254 may be present and should be ignored.
- Clear the SJB DTCs and repeat the self-test.
- Is DTC B2021 retrieved again?
Yes
GO to A3.
No
INSTALL a new interior lamp. CLEAR the DTCs. REPEAT the self-test.
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A3 CHECK CIRCUIT 54 (LG/YE) FOR A SHORT TO VOLTAGE
- Ignition OFF.
- Disconnect: SJB C2280f.
- Ignition ON.
- For vehicles without a convertible top, measure the voltage between the overhead console C930-4, circuit 54 (LG/YE), harness side and ground.
- For vehicles with a convertible top, measure the voltage between the overhead console C9013-4, circuit 54 (LG/YE), harness side and ground.
- Is any voltage present?
Yes
REPAIR the circuit. CLEAR the DTCs. REPEAT the self-test.
No
GO to A11.
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A4 CHECK THE INTERIOR LAMP (DTC B2250)
- Ignition OFF.
- Disconnect: Overhead Console C930 (Without Convertible Top).
- Disconnect: Overhead Console C9013 (With Convertible Top).
- Ignition ON.
- Enter the following diagnostic mode on the scan tool: SJB Self-Test.
- NOTE: DTC B2254 may be present and should be ignored.
- Clear the SJB DTCs and REPEAT the self-test.
- Is DTC B2550 retrieved again?
Yes
GO to A5.
No
INSTALL a new interior lamp. CLEAR the DTCs. REPEAT the self-test.
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A5 CHECK CIRCUIT 53 (BK/LB) FOR A SHORT TO GROUND
- Ignition OFF.
- Disconnect: SJB C2280f.
- For vehicles without a convertible top, measure the resistance between the overhead console C930-5, circuit 53 (BK/LB), harness side and ground.
- For vehicles with a convertible top, measure the resistance between the overhead console C9013-5, circuit 53 (BK/LB), harness side and ground.
- Is the resistance greater than 10,000 ohms?
Yes
GO to A11.
No
REPAIR the circuit. CLEAR the DTCs. REPEAT the self-test.
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A6 CHECK CIRCUIT 53 (BK/LB) FOR VOLTAGE
- Ignition OFF.
- Disconnect: Overhead Console C930 (Without Convertible Top).
- Disconnect: Overhead Console C9013 (With Convertible Top).
- Ignition ON.
- For vehicles without a convertible top, measure the voltage between the overhead console C930-5, circuit 53 (BK/LB), harness side and ground.
- For vehicles with a convertible top, measure the voltage between the overhead console C9013-5, circuit 53 (BK/LB), harness side and ground.
- Is the voltage greater than 10 volts?
Yes
GO to A8.
No
GO to A7.
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A7 CHECK CIRCUIT 53 (BK/LB) FOR AN OPEN
- Ignition OFF.
- Disconnect: SJB C2280f.
- For vehicles without a convertible top, measure the resistance between the overhead console C930-5, circuit 53 (BK/LB), harness side and the SJB C2280f-26, circuit 53 (BK/LB), harness side.
- For vehicles with a convertible top, measure the resistance between the overhead console C9013-5, circuit 53 (BK/LB), harness side and the SJB C2280f-26, circuit 53 (BK/LB), harness side.
- Is the resistance less than 5 ohms?
Yes
GO to A11.
No
REPAIR the circuit. CLEAR the DTCs. REPEAT the self-test.
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A8 CHECK THE GROUND CIRCUIT TO THE OVERHEAD CONSOLE
- Open a door or place the instrument panel dimmer switch in the DOME position.
- For vehicles without a convertible top, measure the voltage between the overhead console C930-5, circuit 53 (BK/LB), harness side and the overhead console C930-4, circuit 54 (LG/YE), harness side.
- For vehicles with a convertible top, measure the voltage between the overhead console C9013-5, circuit 53 (BK/LB), harness side and the overhead console C9013-4, circuit 54 (LG/YE), harness side.
- Is the voltage greater than 10 volts?
Yes
INSTALL a new interior lamp. CLEAR the DTCs. REPEAT the self-test.
No
GO to A9.
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A9 CHECK CIRCUIT 54 (LG/YE) FOR AN OPEN
- Ignition OFF.
- Disconnect: SJB C2280f.
- For vehicles without a convertible top, measure the resistance between the overhead console C930-4, circuit 54 (LG/YE), harness side and the SJB C2280f-25, circuit 54 (LG/YE), harness side.
- For vehicles with a convertible top, measure the resistance between the overhead console C9013-4, circuit 54 (LG/YE), harness side and the SJB C2280f-25, circuit 54 (LG/YE), harness side.
- Is the resistance less than 5 ohms?
Yes
GO to A11.
No
REPAIR the circuit. CLEAR the DTCs. REPEAT the self-test.
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A10 CHECK THE SJB DOOR AJAR AND THE INSTRUMENT PANEL DIMMER SWITCH PIDs
- Enter the following diagnostic mode on the scan tool: SJB DataLogger.
- Monitor the SJB door ajar switch PIDs (D_DR_SW, P_DR_SW) while opening and each door.
- Monitor the SJB instrument panel dimmer switch PID (DOMELM_SW) while operating the instrument panel dimmer switch in the interior lamp ON positions.
- Do the SJB door ajar and instrument panel dimmer switch PIDs correspond?
Yes
GO to A11.
No
For a door ajar switch, Go To Pinpoint Test B. Pinpoint Test B: The Courtesy Lamps Do Not Turn On With One Door Open
For the instrument panel dimmer switch, Go To Pinpoint Test C. Pinpoint Test C: The Courtesy Lamps Are Inoperative - Using The Instrument Panel Dimmer Switch
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A11 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. 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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