Note. The Smart Junction Box (SJB) is also known as the Generic Electronic Module (GEM).
The interior lighting system consists of the following components
- Door ajar switches (part of the door latch)
- Instrument panel dimmer switch
- Interior/map lamps
- Footwell lamps
- Glove compartment lamp
- Vanity mirror lamps
- Liftgate/Trunk Module (LTM)
- Remote Function Actuator (RFA) module
- Puddle lamps
- SJB
- Interior Lighting Control Module (ILCM)
- Ambient lighting select switch
- Ambient lighting dimmer switch
The interior lighting system consists of 3 subsystems
- Courtesy lamps
- Demand lamps
- Ambient lighting
Principles of Operation
Note. The Smart Junction Box (SJB) is also known as the Generic Electronic Module (GEM).
The SJB supplies voltage to the interior lighting system. The interior lighting system illuminates the courtesy lamps to enhance visibility of the interior while a vehicle door is ajar, and the vehicle speed is less than 15 km/h (9 mph) or 5 km/h (3 mph) for puddle lamps. The SJB controls all interior lighting functions and timing by monitoring inputs from the door ajar switches, the instrument panel dimmer switch, and vehicle speed.
The SJB supplies voltage to the courtesy lamps when the SJB receives the required input. The Remote Function Actuator (RFA) module monitors the door ajar switches and sends the input to the SJB over the communication network. The SJB then supplies voltage to the courtesy lamps.
Normal Operation
The Remote Function Actuator (RFA) module sends a voltage signal to each door ajar switch, which is routed to ground with the door closed. When a door is opened, the signal to ground is interrupted, indicating an open door to the RFA module.
The RFA module broadcasts the door ajar message to the Smart Junction Box (SJB) over the Medium Speed Controller Area Network (MS-CAN). When the SJB receives the door ajar message, it provides voltage to the courtesy lamps.
This pinpoint test is intended to diagnose the following
- Wiring, terminals or connectors
- Door ajar switch
- RFA module
The Remote Function Actuator (RFA) module sends a voltage signal to the Liftgate/Trunk Module (LTM), which is routed to ground with the liftgate closed. When the liftgate is opened, the LTM opens the ground signal to the RFA module, indicating an open liftgate to the RFA module.
The RFA module broadcasts the liftgate ajar status to the Smart Junction Box (SJB) over the Medium Speed Controller Area Network (MS-CAN). Based on the ajar status, the SJB supplies voltage to the courtesy lamps.
- DTC B2721 (Liftgate/Decklid Ajar Output Short to Ground or Open) - a continuous and on-demand DTC that sets when the LTM detects a short to ground from the liftgate ajar circuit.
This pinpoint test is intended to diagnose the following
- Wiring, terminals or connectors
- LTM
- RFA module
The Smart Junction Box (SJB) turns the courtesy lamps on and off by monitoring the dimmer switch and dome lamp request input circuits. When the instrument panel dimmer switch is pushed to the second detent up, the SJB receives a signal from the backlighting dim up and dome lamp request circuits, indicating a request to turn the courtesy lamps on. When the instrument panel dimmer switch is pushed to the second detent down, the SJB receives a signal from the backlighting dim down and dome lamp request circuits, indicating a request to turn the courtesy lamps off.
This pinpoint test is intended to diagnose the following
- Wiring, terminals or connectors
- Instrument panel dimmer switch
- SJB
The Smart Junction Box (SJB) fuse 9 (15A) supplies power for the interior courtesy lamps. When the SJB receives the required input (such as an open door or request from the instrument panel dimmer switch), it provides voltage to the interior courtesy lamps.
| DTC Description | Fault Trigger Conditions |
|---|---|
| B106E - Solid State Driver Disabled Due to Short Circuit | A continuous DTC that sets when the SJB has temporarily shut down the output driver. The module has temporarily disabled the interior courtesy lamp output because an excessive current draw exists (such as a short to ground). The SJB cannot enable the interior courtesy lamp output until the cause of the short is corrected, the DTCs have been cleared and a successful self-test is run . |
| B106F - Module Disabled Due to External Fault | A continuous DTC that sets when the SJB has permanently shut down the output driver. The module has permanently disabled the interior courtesy lamp output because an excessive current draw fault (such as a short to ground) has exceeded the limits that the SJB can withstand. The cause of the excessive current draw MUST be corrected before a new SJB is installed . |
| B2A35 - Interior Lighting Output Circuit Open | An on-demand DTC that sets when the SJB detects an open from the interior courtesy lighting output circuit. |
| B2A36 - Interior Lighting Output Circuit Short To Ground | A continuous and on-demand DTC that sets when the SJB detects a short to ground from the interior courtesy lighting output circuit. |
DTC DESCRIPTION TABLE
This Pinpoint Test is intended to diagnose the following
- Fuse
- Wiring, terminals or connectors
- Interior lamp
- SJB
The Smart Junction Box (SJB) provides voltage to the puddle lamps when the courtesy lamps are on (such as when a door is open or when requested from the instrument panel dimmer switch).
- DTC B2A39 (Puddle Lamp Output Circuit Open) - an on-demand DTC that sets when the SJB detects an open from the puddle lamp output circuit.
- DTC B2A3A (Puddle Lamp Output Circuit Short To Ground) - a continuous and on-demand DTC that sets when the SJB detects a short to ground from the puddle lamp output circuit. This DTC also sets when the SJB fuse 10 (15A) has failed or is removed.
This Pinpoint Test is intended to diagnose the following
- Fuse
- Wiring, terminals or connectors
- Exterior mirror
- SJB
The Smart Junction Box (SJB) provides voltage to the scuff plate and puddle lamps when the courtesy lamps are on (such as when a door is open or when requested from the instrument panel dimmer switch).
This Pinpoint Test is intended to diagnose the following
- Fuse
- Wiring, terminals or connectors
- Scuff plate lamp
- SJB
The Remote Function Actuator (RFA) module sends a voltage signal to each door ajar switch, which is routed to ground with the door closed (the door ajar switch is closed when the door is closed). The signal to ground is interrupted when the door is opened, indicating an open door to the RFA module.
The RFA module sends a voltage signal to the Liftgate/Trunk Module (LTM), which is routed to ground with the liftgate closed. When the liftgate is opened, the LTM opens the ground signal to the RFA module, indicating an open liftgate to the RFA module.
When the RFA receives a door or liftgate ajar input, it broadcasts the ajar message to the Smart Junction Box (SJB) over the Medium Speed Controller Area Network (MS-CAN). When the SJB receives the ajar message, it provides voltage to the courtesy lamps.
Note. Make sure all of the doors and the liftgate are closed while carrying out the self-test.
| DTC Description | Fault Trigger Conditions |
|---|---|
| B1320 - Driver Door Ajar Circuit Open | An on-demand DTC that sets when the SJB receives an ajar message for the LH front door during the self-test. |
| B1328 - Passenger Door Ajar Circuit Open | An on-demand DTC that sets when the SJB receives an ajar message for the RH front door during the self-test. |
| B1336 - Door Ajar RR Circuit Open | An on-demand DTC that sets when the SJB receives an ajar message for the RH rear door during the self-test. |
| B1572 - Door Ajar LR Circuit Open | An on-demand DTC that sets when the SJB receives an ajar message for the LH rear door during the self-test. |
| B2077 - Liftgate Ajar Sw Circuit Failure | An on-demand DTC that sets when the SJB receives an ajar message for the liftgate during the self-test. |
SMART JUNCTION BOX (SJB) DTCS TABLE
| DTC Description | Fault Trigger Conditions |
|---|---|
| B2718 - Liftgate/Decklid Ajar Output Short to Battery | A continuous or on-demand DTC that sets when the LTM detects a short to voltage from the liftgate ajar circuit to the RFA module. |
| B2721 - Liftgate/Decklid Ajar Output Short to Ground or Open | A continuous or on-demand DTC that sets when the LTM detects an open from the liftgate ajar circuit to the RFA module. |
LIFTGATE/TRUNK MODULE (LTM) DTCS TABLE
| DTC Description | Fault Trigger Conditions |
|---|---|
| B1175:13 - Driver Door Ajar Switch: Circuit Open | An on-demand DTC that sets when the RFA module detects an open from the LH front door ajar circuit. |
| B1176:13 - Passenger Door Ajar Switch: Circuit Open | An on-demand DTC that sets when the RFA module detects an open from the RH front door ajar circuit. |
| B1178:13 - Boot/Trunk Ajar Switch: Circuit Open | An on-demand DTC that sets when the RFA module detects an open from the liftgate ajar input circuit. |
| B11C0:13 - Driver Side Rear Door Ajar Switch: Circuit Open | An on-demand DTC that sets when the RFA module detects an open from the LH rear door ajar circuit. |
| B11C1:13 - Passenger Side Rear Door Ajar Switch: Circuit Open | An on-demand DTC that sets when the RFA module detects an open from the RH rear door ajar circuit. |
REMOTE FUNCTION ACTUATOR (RFA) MODULE DTCS TABLE
This Pinpoint Test is intended to diagnose the following
- Wiring, terminals or connectors
- Door ajar switch
- LTM
- RFA module
When the Smart Junction Box (SJB) detects a request for the courtesy lamps (such as open door or from the instrument panel dimmer switch), the SJB supplies voltage to the interior courtesy lamps.
- DTC B2A35 (Interior Lighting Output Circuit Open) - an on-demand DTC that sets when the SJB detects a short to voltage from the courtesy lamp output circuit.
This Pinpoint Test is intended to diagnose the following
- Wiring, terminals or connectors
- SJB
When the Smart Junction Box (SJB) detects a request for the courtesy lamps (such as open door or from the instrument panel dimmer switch), the SJB provides voltage to the puddle lamps.
- DTC B2A39 (Puddle Lamp Output Circuit Open) - an on-demand DTC that sets when the SJB detects a short to voltage from the puddle lamp output circuit.
This Pinpoint Test is intended to diagnose the following
- Wiring, terminals or connectors
- SJB
The Smart Junction Box (SJB) energizes the battery saver relay based on inputs from the ignition status, the ajar switches, the Remote Keyless Entry (RKE) transmitter, the keyless entry keypad and the instrument panel dimmer switch. When the battery saver relay is energized, it supplies voltage to the demand lamps.
This Pinpoint Test is intended to diagnose the following
- Fuse
- Wiring, terminals or connectors
- SJB
The Smart Junction Box (SJB) supplies voltage to the demand lamps when the battery saver relay is energized.
This Pinpoint Test is intended to diagnose the following
- Wiring, terminals or connectors
- Interior lamp
The Smart Junction Box (SJB) provides a battery saver function. The battery saver function provides automatic shutoff of the interior lamps (courtesy lamps and demand lamps) after 10 minutes have elapsed in order to save battery power.
A timer in the SJB is started when the ignition is placed in the OFF mode, all the doors and the liftgate are closed. When the time-out period for the lamps has elapsed, the SJB automatically shuts off voltage to the lamps.
This Pinpoint Test is intended to diagnose the following
- Wiring, terminals or connectors
- SJB
The Interior Lighting Control Module (ILCM) supplies voltage and ground to the LEDs located in the floor console cup holders, storage tray, storage bin, inside door handles and map pockets and the front and rear footwells. The ILCM turns the ambient lighting on to a pre-set color (white) and brightness setting when a door/liftgate is open or the illuminated entry/exit feature is active. The ambient lighting is also active when the ignition is in the RUN mode and the parking lamps are on.
The ambient lighting switch is used to cycle through the 5 color combinations or to turn the ambient lighting feature off. There are 4 different color (red, blue, green and white) LEDs housed within each LED assembly.
The ILCM sends a voltage signal to the ambient lighting switch. When the ambient lighting switch (a momentary contact switch) is pressed to cycle the color setting, the voltage signal is routed to ground, indicating a request for the module to cycle the ambient lighting to the next color setting or to turn the ambient lighting off.
The ambient lighting dimmer switch is used to decrease or increase the lighting intensity.
The color and brightness settings can only be changed when the ignition is in the RUN mode, the parking lamps are on, the liftgate and all the doors are closed.
- DTC B2B18 (Ambient Light Switch Input Fault) - a continuous and on-demand DTC that sets when the ILCM detects a short to ground from the ambient lighting switch input circuit.
This Pinpoint Test is intended to diagnose the following
- Wiring, terminals or connectors
- Ambient lighting harness
- Ambient lighting switch
- ILCM
The Interior Lighting Control Module (ILCM) turns the ambient lighting on to a pre-set color (white) and brightness setting when a door is open or the illuminated entry feature is active. The ambient lighting is also active when the ignition is in the RUN mode and the parking lamps are on.
The ILCM sends a voltage signal to the ambient lighting switch. When the ambient lighting switch (a momentary contact switch) is pressed to cycle the color setting, the voltage signal is routed to ground, indicating a request for the module to cycle the ambient lighting to the next color setting or to turn the ambient lighting off.
The color and brightness settings can only be changed when the ignition is in the RUN mode, the parking lamps are on and the doors are closed.
| DTC Description | Fault Trigger Conditions |
|---|---|
| B2B00 - Ambient Light Zone 1 Red Circuit Open | A continuous and on-demand DTC that sets when the ILCM detects an open from the ambient lighting zone 1 red circuit. |
| B2B01 - Ambient Light Zone 1 Red Circuit Short to Ground | A continuous and on-demand DTC that sets when the ILCM detects a short to ground from the ambient lighting zone 1 red circuit. |
| B2B02 - Ambient Light Zone 1 Green Circuit Open | A continuous and on-demand DTC that sets when the ILCM detects an open from the ambient lighting zone 1 green circuit. |
| B2B03 - Ambient Light Zone 1 Green Circuit Short to Ground | A continuous and on-demand DTC that sets when the ILCM detects a short to ground from the ambient lighting zone 1 green circuit. |
| B2B04 - Ambient Light Zone 1 Blue Circuit Open | A continuous and on-demand DTC that sets when the ILCM detects an open from the ambient lighting zone 1 blue circuit. |
| B2B05 - Ambient Light Zone 1 Blue Circuit Short to Ground | A continuous and on-demand DTC that sets when the ILCM detects a short to ground from the ambient lighting zone 1 blue circuit. |
| B2B06 - Ambient Light Zone 1 Signature Circuit Open | A continuous and on-demand DTC that sets when the ILCM detects an open from the ambient lighting zone 1 white circuit. |
| B2B07 - Ambient Light Zone 1 Signature Circuit Short to Ground | A continuous and on-demand DTC that sets when the ILCM detects a short to ground from the ambient lighting zone 1 white circuit. |
| B2B08 - Ambient Light Zone 2 Red Circuit Open | A continuous and on-demand DTC that sets when the ILCM detects an open from the ambient lighting zone 2 red circuit. |
| B2B09 - Ambient Light Zone 2 Red Circuit Short to Ground | A continuous and on-demand DTC that sets when the ILCM detects a short to ground from the ambient lighting zone 2 red circuit. |
| B2B0A - Ambient Light Zone 2 Green Circuit Open | A continuous and on-demand DTC that sets when the ILCM detects an open from the ambient lighting zone 2 green circuit. |
| B2B0B - Ambient Light Zone 2 Green Circuit Short to Ground | A continuous and on-demand DTC that sets when the ILCM detects a short to ground from the ambient lighting zone 2 green circuit. |
| B2B0C - Ambient Light Zone 2 Blue Circuit Open | A continuous and on-demand DTC that sets when the ILCM detects an open from the ambient lighting zone 2 blue circuit. |
| B2B0D - Ambient Light Zone 2 Blue Circuit Short to Ground | A continuous and on-demand DTC that sets when the ILCM detects a short to ground from the ambient lighting zone 2 blue circuit. |
| B2B0E - Ambient Light Zone 2 Signature Circuit Open | A continuous and on-demand DTC that sets when the ILCM detects an open from the ambient lighting zone 2 white circuit. |
| B2B0F - Ambient Light Zone 2 Signature Circuit Short to Ground | A continuous and on-demand DTC that sets when the ILCM detects a short to ground from the ambient lighting zone 2 white circuit. |
| B2B10 - Ambient Light Zone 3 Red Circuit Open | A continuous and on-demand DTC that sets when the ILCM detects an open from the ambient lighting zone 3 red circuit. |
| B2B11 - Ambient Light Zone 3 Red Circuit Short to Ground | A continuous and on-demand DTC that sets when the ILCM detects a short to ground from the ambient lighting zone 3 red circuit. |
| B2B12 - Ambient Light Zone 3 Green Circuit Open | A continuous and on-demand DTC that sets when the ILCM detects an open from the ambient lighting zone 3 green circuit. |
| B2B13 - Ambient Light Zone 3 Green Circuit Short to Ground | A continuous and on-demand DTC that sets when the ILCM detects a short to ground from the ambient lighting zone 3 green circuit. |
| B2B14 - Ambient Light Zone 3 Blue Circuit Open | A continuous and on-demand DTC that sets when the ILCM detects an open from the ambient lighting zone 3 blue circuit. |
| B2B15 - Ambient Light Zone 3 Blue Circuit Short to Ground | A continuous and on-demand DTC that sets when the ILCM detects a short to ground from the ambient lighting zone 3 blue circuit. |
| B2B16 - Ambient Light Zone 3 Signature Circuit Open | A continuous and on-demand DTC that sets when the ILCM detects an open from the ambient lighting zone 3 white circuit. |
| B2B17 - Ambient Light Zone 3 Signature Circuit Short to Ground | A continuous and on-demand DTC that sets when the ILCM detects a short to ground from the ambient lighting zone 3 white circuit. |
DTC DESCRIPTION TABLE
This Pinpoint Test is intended to diagnose the following
- Wiring, terminals or connectors
- Ambient lighting harness
- ILCM
The Interior Lighting Control Module (ILCM) sends voltage signals to the ambient lighting dimmer switch to monitor the dim up and dim down input requests. When the switch is pressed up or down, it routes the corresponding circuit to ground, indicating a request to increase or decrease the ambient lighting brightness setting.
- DTC B2B18 (Ambient Light Switch Input Fault) - a continuous and on-demand DTC that sets when the ILCM detects a short to ground from the ambient lighting dimmer switch up or down input circuit.
This Pinpoint Test is intended to diagnose the following
- Wiring, terminals or connectors
- Ambient lighting harness
- Ambient lighting dimmer switch
- ILCM
- DTC U0140 (Lost Communication With Body Control Module (GEM) - set by the Interior Lighting Control Module (ILCM) when network messages are missing from the Smart Junction Box (SJB) for greater than 5 seconds. As more than one module receives these messages, all modules receiving a particular message should exhibit a symptom if the message is missing. For a complete list of all network messages, refer to «MODULE COMMUNICATIONS NETWORK»(ref-356606) .
This Pinpoint Test is intended to diagnose the following
- Communication network concern
- SJB