| 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 smart junction box (SJB) is connected to the instrument cluster through the medium speed controller area network (MS-CAN) communication network. The SJB controls both interior and exterior lighting, body functions, active anti-theft functions (perimeter alarm), remote keyless entry (RKE) functions. The SJB is a combination of a multifunction control module and an interior fuse panel. The SJB is connected with a coaxial antenna to receive wireless signals from the RKE transmitters. The SJB controls several vehicle systems which include: - Exterior lamps
- Illuminated entry
- Interior lamps
- Perimeter anti-theft
- Power door locks
- Rear windshield wiper
- Remote keyless entry (RKE)
- Warning chimes
In addition, the SJB is involved in other vehicle systems through communication over the controller area network (CAN). For a detailed list of SJB network inputs and outputs, refer to Section 418-00 Module Communications Network, principles of operation. The SJB must be configured when being replaced. The configuration must be downloaded to the scan tool before the original SJB is removed and then the configuration must be downloaded into the new SJB after it has been installed. Refer to Section 418-01 Module Configuration, programmable module installation (PMI). In addition to module configuration, some SJB parameters (customer preference items) are programmable. Refer to Section 418-01 Module Configuration for additional information on programmable parameters. The SJB utilizes a protective circuit strategy for many of its outputs (for example, the headlamp output circuit). Output loads (current level) are monitored for excessive current (typically short circuits) and are shut down (turns off the voltage or ground provided by the module) when a fault is detected. A continuous DTC is stored at that time for the fault. The circuit will then reset after an ignition cycle or customer demand of the function (switching the component on, 30-minute battery saver being energized). When an excessive circuit load occurs several times, the module shuts down the output until a service procedure is performed. At the same time, the continuous DTC that was stored on the first failure will not clear by a command to clear the continuous DTCs. The module will not allow this code to be cleared or the circuit restored to normal until a successful on-demand self-test proves that the fault has been repaired. After the on-demand self-test has successfully completed (no on-demand DTCs present), the continuous DTC will have been cleared and the circuit function will return. DTC B106E and B106F — are set when the SJB has been disabled due to a repetitive fault causing a circuit overload. When DTC B106F is set, the SJB must be replaced after the circuit overload has been repaired. If the circuit overload is not repaired before installing a new SJB, the new SJB will be damaged. A corresponding DTC for the circuit in question will also be set as follows: - DTC B1034 — Audio unit start circuit short to B+
- DTC B1218 — Horn relay circuit short to B+
- DTC B1304 — Accessory delay relay circuit short to B+
- DTC B1316 — Battery saver relay coil circuit short to B+
- DTC B1349 — Rear window defroster relay circuit short to B+
- DTC B1474 — Battery saver power relay circuit short to B+
- DTC B1502 — Left turn signal lamp output circuit short to ground
- DTC B1506 — Right turn signal lamp output circuit short to ground
- DTC B2070 — Trailer tow relay circuit short to ground
- DTC B2501 — Left headlamp low beam circuit short to B+ or ground
- DTC B2503 — Right headlamp low beam circuit short to B+ or ground
- DTC B2505 — Left headlamp high beam circuit short to B+ or ground
- DTC B2507 — Right headlamp high beam circuit short to B+ or ground
- DTC B2512 — Fog lamp relay circuit short to B+
- DTC C1961 — Park lamp relay circuit short to ground
- DTC P0930 — Gear shift lock solenoid circuit short to ground
Inspection and Verification - Verify the customer concern.
- Visually inspect the following for obvious signs of mechanical or electrical damage.
Visual Inspection Chart | Electrical | - Smart junction box (SJB) fuses:
- Circuitry
| - 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 software release. 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 SJB.
- If no DTCs related to the concern are retrieved, GO to Symptom Chart.
Symptom Chart Symptom Chart | Symptom | Possible Sources | Action | | No communication with the smart junction box (SJB) | * Fuse * Circuitry * SJB | * | Pinpoint Tests Pinpoint Test A: DTC B106E — Solid State Driver Disabled Due To Short Circuit Normal Operation When a repetitive fault causing a circuit overload is detected on certain output circuits, the smart junction box (SJB) disables the circuit by removing voltage, or ground, to the affected circuit. The circuit remains disabled until the fault is corrected and an on-demand self-test is run. After the on-demand self-test has been run, any DTCs related to the fault will be cleared. DTC B106E — sets when the SJB has disabled a circuit due to a repetitive fault causing a circuit overload. For a complete list of corresponding DTCs, refer to Principles of Operation in this section. DTC B106F — sets when one or more output functions are permanently disabled due to a repetitive circuit overload fault. DTC B106F will be set with DTC B106E. When DTC B106F is present, the SJB must be replaced after the fault condition has been corrected. Possible Causes - Output circuit short to ground or voltage
- SJB
| PINPOINT TEST A : DTC B106E — SOLID STATE DRIVER DISABLED DUE TO SHORT CIRCUIT | CAUTION:If DTC B106F is present and the SJB is to be replaced, the fault condition must be corrected first. Failure to correct the fault condition first may cause damage to the new SJB, resulting in a repeat repair. | | TEST CONDITIONS | DETAILS/RESULTS/ACTIONS | | A1: REVIEW THE DTCS | | | 1 Review the DTCs from the SJB self-test. | | | Are only DTC B106E and DTC B106F present? Yes No | | A2: CARRY OUT THE SJB SELF-TEST | | | 1 Carry out the SJB self-test. | | | Is DTC B106F present? Yes No The system is operating correctly at this time. The concern was caused by a fault in one of the output circuits. | |
