Principles of Operation
Note. The Smart Junction Box (SJB) is also known as the Generic Electronic Module (GEM).
When a vehicle door is ajar with the vehicle speed less than 15 km/h (9 mph) or 5 km/h (3 mph) for puddle lamps, or a request from the instrument panel dimmer switch is received, the SJB provides voltage to the interior courtesy and puddle lamp circuits. The SJB controls all interior lighting functions and timing by monitoring inputs from the door ajar switches, the instrument panel dimmer switch, the Remote Keyless Entry (RKE) transmitter and vehicle speed.
Normal Operation
When any door is open, the ajar switch opens the circuit to the Smart Junction Box (SJB). The SJB monitors the ajar circuits, and based on the ajar status, the SJB supplies voltage to the courtesy lamps.
When 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 SJB provides voltage to the courtesy lamps.
This pinpoint test is intended to diagnose the following
- Wiring, terminals or connectors
- Door ajar switch
- SJB
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 requested 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 requested 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
Power is supplied to the interior courtesy lamps and cargo lamp by the Smart Junction Box (SJB) fuse 9 (15A). Based on the input status, the SJB supplies 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 TABLE
This pinpoint test is intended to diagnose the following
- Fuse
- Wiring, terminals or connectors
- Interior lamp
- SJB
Power is supplied to the puddle lamps through the Smart Junction Box (SJB) fuse 10 (15A). Based on the input status, the SJB supplies voltage to the puddle lamps. 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 as a result when the SJB fuse 10 (15A) has failed or is removed. |
DTC TABLE
This pinpoint test is intended to diagnose the following
- Fuse
- Wiring, terminals or connectors
- Exterior mirror
Power is supplied to the luggage compartment lamp from the demand lighting circuit. Ground for the luggage compartment lamp is controlled by the luggage compartment latch. When the luggage compartment lid is opened, a switch inside the latch closes and completes the path to ground.
- DTC B1331 (Decklid Ajar Rear Door Circuit Failure) - an on-demand DTC that sets when the SJB detects an open from the luggage compartment lid ajar input circuit.
This pinpoint test is intended to diagnose the following
- Wiring, terminals or connectors
- Luggage compartment lamp
- Luggage compartment lid latch
When any door or liftgate 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 interior 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 TABLE
This pinpoint test is intended to diagnose the following
- Wiring, terminals or connectors
- Door ajar switch
- SJB
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
The Smart Junction Box (SJB) supplies voltage to the demand lamps. The demand lamps are ground through one circuit. The glove compartment lamp (MKZ only) is case grounded.
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. The demand lamps are grounded through one circuit. The glove compartment lamp (MKZ only) is case grounded.
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
When the ignition key is in the RUN or ACC position, the ambient lighting module 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 8 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.
When the ignition key is in the RUN or ACC position, the ambient lighting switch and the ambient lighting module receive voltage. When the ambient lighting switch (a momentary contact switch) is pressed, voltage is routed to the ambient lighting module indicating a request for the module to cycle the ambient lighting to the next setting.
This pinpoint test is intended to diagnose the following
- Fuse
- Wiring, terminals or connectors
- Ambient lighting harness
- Ambient lighting switch
- Ambient lighting module
When the ignition key is in the RUN or ACC position, the ambient lighting module 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 8 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.
When the ignition key is in the RUN or ACC position, the ambient lighting switch and the ambient lighting module receive voltage. When the ambient lighting switch (a momentary contact switch) is pressed, voltage is routed to the ambient lighting module indicating a request for the module to cycle the ambient lighting to the next setting.
This pinpoint test is intended to diagnose the following
- Wiring, terminals or connectors
- Ambient lighting harness
- Ambient lighting switch
- Ambient lighting module
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 select switch is used to cycle through the 8 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 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 select switch input circuit.
This pinpoint test is intended to diagnose the following
- Wiring, terminals or connectors
- Ambient lighting harness
- Ambient lighting select 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 select switch is used to cycle through the 8 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 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. |
| 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 signature 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. |
| 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 signature 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. |
| 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 signature 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. |
| 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 signature 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. |
| 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 signature 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. |
| 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 signature circuit. |
DTC TABLE
This pinpoint test is intended to diagnose the following
- Wiring, terminals or connectors
- Ambient lighting harness
- Ambient lighting select switch
- ILCM
The Interior Lighting Control Module (ILCM) sends 2 voltage reference signals to the ambient lighting dimmer switch (dim up or dim down). When the ambient lighting dimmer switch (a momentary contact switch) is pressed (dim up or dim down), the voltage signal is routed to the ground indicating a request for the module to cycle the ambient lighting to the next dim up or dim down 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 dim up or dim 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 SJB ) - set by the Interior Lighting Control Module (ILCM) if data messages received from the SJB over the Medium Speed Controller Area Network (MS-CAN) are missing. For a complete list of all network messages, refer to «DESCRIPTION AND OPERATION»(ref-355946-S23164808342010013000000) . This pinpoint test is intended to diagnose the following
- Wiring, terminals or connectors
- ILCM