Battery Saver
Note. Time-out is 1 minute if the vehicle has less than 80 km (50 miles).
To save battery voltage, the BCM provides automatic shut-off of the courtesy and demand lamps after a time-out period when the ignition is off. A timer in the BCM starts when any of the following occur
- the ignition changes to off
- any door or liftgate becomes ajar while the ignition is off
- an UNLOCK button of the Remote Keyless Entry (RKE) transmitter is pressed while the ignition is off
- a valid keypad code is entered while the ignition is off
- the instrument panel dimmer switch is used to turn the courtesy lamps on while the ignition is off
When 10 minutes have elapsed, the BCM automatically shuts off voltage to the lamps. The timer restarts (voltage is restored if the BCM is in battery saver mode) if any of the following occurs
- the ignition changes out of off
- any door or liftgate becomes ajar
- the UNLOCK button of the Remote Keyless Entry (RKE) transmitter is pressed
- a valid keypad code is entered
- the instrument panel dimmer switch is pressed
Courtesy Lamps
The courtesy lamps subsystem consists of the door ajar switches (integrated into the door latches), the interior lamps, the cargo lamp, the puddle lamps, the scuff plate lamps, the FLM, and the BCM.
Illuminated Entry
The illuminated entry requests the dimmable backlighting, the parking lamps and the courtesy lamps to illuminate when the ignition is off and a door or liftgate is opened, the RKE transmitter UNLOCK button is pressed, or the vehicle is unlocked using the keyless entry keypad. If no doors are open, the illuminated entry requests the lamps off after 25 seconds have elapsed, the ignition switched out of off, the RKE transmitter LOCK button is pressed, or the vehicle is locked using the keyless entry keypad.
Interior Lighting Delay
The interior lighting delay feature provides temporary illumination of the dimmable backlighting, the parking lamps and the courtesy lamps after the doors are opened and then closed. The interior lighting delay feature keeps the lamps on for a period of 25 seconds after all the doors are closed. If during the 25 second delay time the BCM detects the ignition has been switched out of off, or if the vehicle is locked using the RKE transmitter or the keyless entry keypad, the lamp illumination is discontinued.
Illuminated Exit
The illuminated exit requests the dimmable backlighting, the parking lamps, and the courtesy lamps to illuminate for 25 seconds after all doors are closed and the ignition is turned off. The illuminated exit deactivates when the ignition transitions out of off, a door or liftgate becomes ajar, or 25 seconds have elapsed.
Theater Lighting
The theater lighting feature ramps-up the courtesy lamps over 0.7 second when courtesy lamp activation is requested. The theater lighting feature ramps-down the courtesy lamps over 1.7 seconds when interior lighting deactivation is requested by any feature other than the panic alarm or battery saver.
Dark Car
The dark car configuration disables the activation of the illuminated entry and illuminated exit features when active. The courtesy lamps can still be activated by the instrument panel dimmer switch.
Demand Lamps
The demand lamps subsystem consists of the map/reading lamps, the glove compartment lamp (MKX) and the vanity mirror lamps located in the visors. The BCM energizes the battery saver relay to supply voltage to the demand lamps when the battery saver feature is not active.
Ambient Lighting
The ambient lighting subsystem provides illumination to the center console cupholders, the storage bin, the door map pockets, the door pull handles, the door release handles, and the front and rear footwells for illuminated entry or when the ignition is in run with the parking lamps on. The ambient lighting is controlled using the touch screen display in the center of the instrument panel.
When the illuminated entry feature is active, the ambient lighting defaults to a pre-set color and brightness setting. When all the doors are closed and the illuminated entry is no longer active, the ambient lighting returns to the last color and brightness setting that was set by the operator.
The touch screen display is used to select one of 7 color combinations or turn the ambient lighting feature on or off. The ambient lighting system retains the last color setting and brightness between uses. For vehicles with memory seats, the ambient lighting color can also be set to correspond to the Driver 1 or Driver 2 settings.
SPECIAL TOOLS CHART Fluke 77-IV Digital Multimeter FLU77-4 or equivalent Vehicle Communication Module (VCM) and Integrated Diagnostic System (IDS) software with appropriate hardware, or equivalent scan tool Flex Probe Kit NUD105-R025D or equivalent
Scheme 20
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Scheme 22
Interior Lamp Arbitrator
The interior lamp arbitrator (programming within the BCM) chooses between the interior lighting delay, the illuminated entry and exit, the battery saver, and the alarm flash processing to determine which feature has precedence of activating and deactivating the interior lamps.
The HVAC module controls the ambient lighting system. When requested, the HVAC module provides voltage and ground to the LEDs. There are 3 LEDs (Edge) (red, blue and green) or 4 LEDs (MKX) (red, blue, green and white) housed within each LED assembly. By illuminating various color combinations, the LEDs are able to produce 7 different colors of ambient light.
The HVAC module receives input from the Accessory Protocol Interface Module (APIM) and the Body Control Module (BCM) over the communication network for color and brightness settings.
The display interface in the center of the instrument panel is used to cycle through different color variations or turn the ambient lighting feature on or off. The APIM communicates messages over the High Speed Controller Area Network (HS-CAN) to the Body Control Module (BCM).
The BCM gateways the messages to the HVAC module over the Medium Speed Controller Area Network (MS-CAN). The HVAC module retains the last color and brightness setting between uses.
Field-Effect Transistor (FET) Protection
A Field-Effect Transistor (FET) is a type of transistor that, when used with module software, monitors and controls current flow on module outputs. The FET protection strategy prevents module damage in the event of excessive current flow.
The BCM utilizes an FET protective circuit strategy for many of its outputs (for example, a 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 event is detected. A short circuit DTC is stored at the fault event and a cumulative counter is started.
When the demand for the output is no longer present, the module resets the FET circuit protection to allow the circuit to function. The next time the driver requests a circuit to activate that has been shut down by a previous short (FET protection) and the circuit is still shorted, the FET protection shuts off the circuit again and the cumulative counter advances.
When the excessive circuit load occurs often enough, the module shuts down the output until a repair procedure is carried out. Each FET protected circuit has 3 predefined levels of short circuit tolerance based on the harmful effect of each circuit fault on the FET and the ability of the FET to withstand it. A module lifetime level of fault events is established based upon the durability of the FET. If the total tolerance level is determined to be 600 fault events, the 3 predefined levels would be 200, 400 and 600 fault events.
When each tolerance level is reached, the short circuit DTC that was stored on the first failure cannot be cleared by a command to clear the continuous DTCs. The module does not allow this code to be cleared or the circuit restored to normal operation until a successful self-test proves that the fault has been repaired. After the self-test has successfully completed (no on-demand DTCs present), DTC U1000:00 and the associated DTC (the DTC related to the shorted circuit) automatically clears and the circuit function returns.
When each level is reached, the DTC associated with the short circuit sets along with DTC U1000:00. These DTCs are cleared using the module on-demand self-test, then the Clear DTC operation on the scan tool (if the on-demand test shows the fault corrected). The module never resets the fault event counter to zero and continues to advance the fault event counter as short circuit fault events occur.
If the number of short circuit fault events reach the third level, then DTCs U1000:00 and U3000:49 set along with the associated short circuit DTC. DTC U3000:49 cannot be cleared and the module must be replaced after the repair.
The BCM FET protected output circuits for the interior lighting system are the interior courtesy lamp and puddle lamp output circuits.