Note. The Smart Junction Box (SJB) is also known as the Generic Electronic Module (GEM).
The interior lighting system consists of the following components
- Ambient lighting switch
- Door ajar switches (part of the latch assembly)
- Instrument panel dimmer switch
- Interior/map lamps
- Interior Lighting Control Module (ILCM)
- Luggage compartment lamp (if equipped)
- Puddle lamps
- SJB
- Vanity mirror lamps
The interior lighting system consists of up to 3 subsystems
- Courtesy lamps
- Demand lamps
- Ambient lighting (if equipped)
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.
Normal Operation
The Smart Junction Box (SJB) (vehicles without Intelligent Access (IA)) or the Remote Function Actuator (RFA) module (vehicles with IA ) send a voltage signal to each door ajar switch, which is routed to ground when the door is closed (the door ajar switch is closed when the door is closed). When the door is opened, the signal to ground is interrupted indicating an open door to the SJB or the RFA module.
For vehicles with IA , the RFA module then sends a door ajar message to the SJB over the communication network.
When the SJB detects an open door, the SJB provides voltage to the courtesy lamps.
This pinpoint test is intended to diagnose the following
- Wiring, terminals or connectors
- Door ajar switch
- SJB
- RFA module
The Smart Junction Box (SJB) turns the courtesy lamps on and off by monitoring the dimmer switch input and the dome lamp request input circuits. When the instrument panel dimmer switch is pushed to the second detent up, the backlighting dim up circuit and the dome request circuit are both grounded to indicate a request to turn the courtesy lamps on. When the instrument panel dimmer switch is pushed to the second detent down, the backlighting dim down circuit and the dome request circuit are both grounded to indicate 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), the SJB 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 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 courtesy lighting output circuit. |
DTC DESCRIPTION
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). The puddle lamps have separate ground circuits.
| 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 puddle lamp output because an excessive current draw exists (such as a short to ground). The SJB cannot enable the puddle 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 puddle 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. |
| B2A39 - Puddle Lamp Output Circuit Open | An on-demand DTC that sets when the SJB detects an open on the puddle lamp output circuit. |
| B2A3A - Puddle Lamp Output Circuit Short To Ground | A continuous and on-demand DTC that sets when the SJB detects a short to ground on the puddle lamp output circuit. This DTC may also set when the SJB fuse 10 (15A) has failed or is removed. |
DTC DESCRIPTION CHART
This pinpoint test is intended to diagnose the following
- Fuse
- Wiring, terminals or connectors
- Exterior mirror
The Smart Junction Box (SJB) supplies voltage to the luggage compartment lamp when the battery saver relay is energized. The luggage compartment lamp ground is a series circuit that is comprised of 2 circuits and the luggage compartment ajar switch. When the luggage compartment lid is ajar, the ajar switch closes and completes the ground path by connecting the circuit. 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.
- DTC B1331 (Decklid Ajar Rear Door Circuit Failure) - an on-demand DTC that sets when the SJB detects an open from the luggage compartment ajar input circuit to the SJB .
- DTC B1178:13 (Boot/Trunk Ajar Switch: Circuit Open) - an on-demand DTC that sets when the Remote Function Actuator (RFA) module detects an open from the luggage compartment ajar input circuit to the RFA module.
This pinpoint test is intended to diagnose the following
- Wiring, terminals or connectors
- Luggage compartment lamp
- Luggage compartment lid latch
The Smart Junction Box (SJB) (vehicles without the Intelligent Access (IA)) or the Remote Function Actuator (RFA) module (vehicles with the IA ) send a voltage signal to each door ajar switch, which is routed to ground when the door is closed (the door ajar switch is closed when the door is closed). When the door is opened, the signal to ground is interrupted indicating an open door to the SJB or the RFA module.
The SJB also sends a voltage signal to the instrument panel dimmer switch. When the instrument panel dimmer switch is rotated to the DOME LAMP position, the voltage signal is routed to ground indicating a request for the courtesy lamps.
When the SJB or the RFA module detects an open door or a request from the instrument panel dimmer switch, voltage is provided to the courtesy lamps.
| DTC Description | Fault Trigger Conditions |
|---|---|
| B1320 - Driver Door Ajar Circuit Open | An on-demand DTC that sets when the SJB detects an open from the LH front door ajar input circuit. |
| B1328 - Passenger Door Ajar Circuit Open | An on-demand DTC that sets when the SJB detects an open from the RH front door ajar input circuit. |
| B1336 - Door Ajar RR Circuit Open | An on-demand DTC that sets when the SJB detects an open from the RH rear door ajar input circuit. |
| B1572 - Door Ajar LR Circuit Open | An on-demand DTC that sets when the SJB detects an open from the LH rear door ajar input circuit. |
| 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. |
DTC DESCRIPTION CHART
When the request from the instrument panel dimmer switch is detected, any door is opened, a correct unlock code from the keyless entry keypad or an unlock request from a programmed Remote Keyless Entry (RKE) transmitter is detected, the Smart Junction Box (SJB) supplies 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
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
The Smart Junction Box (SJB) energizes the battery saver relay based on inputs from the ignition status, ajar switches, Remote Keyless Entry (RKE) transmitter, keyless entry keypad, and the instrument panel dimmer switch (when rotated to the dome position). When the battery saver relay is energized, it supplies voltage to the demand lamps. The demand lamps are grounded at each lamp by the switch.
This pinpoint test is intended to diagnose the following
- Wiring, terminals or connectors
- SJB
The Smart Junction Box (SJB) supplies voltage to the demand lamps when the battery saver relay is energized. The demand lamps are grounded at each lamp by the switch.
This pinpoint test is intended to diagnose the following
- Wiring, terminals or connectors
- Demand lamp
The Smart Junction Box (SJB) controls the 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.
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, door map pockets and the front and rear footwells. The ambient lighting select switch is used to cycle through the 5 color combinations or to turn the ambient lighting feature off. There are 3 different color (red, blue and green) LEDs housed within each LED assembly.
The ILCM sends a voltage signal to the ambient lighting select switch. When the ambient lighting switch (a momentary contact switch) is pressed, the voltage signal is routed to ground indicating a request for the module to cycle the ambient lighting to the next color 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 switch input circuit.
This pinpoint test is intended to diagnose the following
- Wiring, terminals or connectors
- Ambient lighting switch
- ILCM
The Interior Lighting Control Module (ILCM) supplies voltage and ground to the LEDs located in the floor console cup holders, door map pockets and the front and rear footwells. The ambient lighting select switch is used to cycle through the 8 color combinations or to turn the ambient lighting feature off. There are 3 different color (red, blue and green) LEDs housed within each LED assembly.
The ILCM sends a voltage signal to the ambient lighting select switch. When the ambient lighting switch (a momentary contact switch) is pressed, the voltage signal is routed to ground indicating a request for the module to cycle the ambient lighting to the next color setting.
| DTC Description | Fault Trigger Conditions |
|---|---|
| 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. |
| 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. |
| 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. |
| 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. |
| 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. |
| 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. |
| 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. |
| 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. |
| 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. |
| 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. |
| 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. |
| 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. |
| 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. |
| 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. |
| 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. |
| 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. |
| 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. |
| 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. |
DTC DESCRIPTION
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) supplies voltage and ground to the LEDs located in the floor console cup holders, storage tray, storage bin, door map pockets and the front and rear footwells. The ambient lighting switch is used to cycle through the 5 color combinations or to turn the ambient lighting feature off. There are 3 different color (red, blue and green) LEDs housed within each LED assembly.
This pinpoint test is intended to diagnose the following
- Wiring, terminals or connectors
- Ambient lighting harness
- Ambient lighting switch
- ILCM
- DTC U0140 (Lost Communication With Body Control Module ( GEM ) - sets in the Interior Lighting Control Module (ILCM) if data messages are missing or not received from the Smart Junction Box (SJB) over the Medium Speed Controller Area Network (MS-CAN). For a complete list of all network messages, Refer to «MODULE COMMUNICATIONS NETWORK»(ref-355713) .
This pinpoint test is intended to diagnose the following
- Wiring, terminals or connectors
- SJB