Lincoln Nautilus Manuals

Lincoln Nautilus: Voltage Converter/Inverter / Direct Current/Direct Current (DC/DC) Converter Control Module - System Operation and Component Description. Description and Operation

Lincoln Nautilus 2018-2022 Service Manual / Electrical / Battery and Charging System / Voltage Converter/Inverter / Direct Current/Direct Current (DC/DC) Converter Control Module - System Operation and Component Description. Description and Operation

System Diagram


Item Description
1 High Current BJB
2 Ignition Relay
3 PCM
4 DCDC
5 BCM
6 Front Park Assist Camera
7 Rear Park Assist Camera
8 SODL
9 ACM
10 APIM
11 IPC
12 FCIM
13 RTM
14 GSM
15 GWM
16 SCCM
17 IPMB
18 SODR
19 Collision Avoidance Detection System

System Operation

  Network Message Chart


Broadcast Message Originating Module Message Purpose
Engine status   PCM Used to indicate the type of cranking event occurring. If the signal is state 2, Engine Auto Stopped, then the next commanded crank is to be supported. If the signal is state 0, Engine Off, the next crank will be a key crank and the Direct Current/Direct Current (DC/DC) converter control module will not support.

The Direct Current/Direct Current (DC/DC) converter control module, also known as the Voltage Quality Module (VQM), is responsible for boosting battery voltage to specific components on vehicles equipped with the auto-start-stop system. When the ignition is turned on the Direct Current/Direct Current (DC/DC) converter control module initializes after receiving the Run/Start power feed from the BCM controlled run/start relay.

While in stand-by mode the Direct Current/Direct Current (DC/DC) converter control module performs self-diagnostics and is not producing any boost output voltage. The Direct Current/Direct Current (DC/DC) converter control module is simply passing battery voltage straight through to downstream loads when it is in stand-by mode.

The Direct Current/Direct Current (DC/DC) converter control module continuously communicates it's status to the PCM via HS-CAN1 . If the Direct Current/Direct Current (DC/DC) converter control module is overloaded, overheated, or other faults are present the PCM disables the auto-start-stop system. If a fault is detected, the PCM may restart the engine if an auto-start-stop event is already in progress. During an auto-start-stop event the engine shuts down automatically after vehicle speed is zero. As the engine begins shutting down, there is an initial battery voltage drop due to the engine shutting off and the alternator no longer providing output current.

Once the engine is no longer spinning, the electrical system is fully supported by the vehicle battery. The electrical load present in the engine off phase of the auto-start-stop event causes a gradual decline in battery voltage. This gradual decline of battery voltage is the second voltage transition. The third voltage transition occurs during the engine restart. The system voltage drops, followed by the system voltage increasing to the regulation voltage point determined by the alternator output.

Prior to the engine restart, the PCM sends a low-side drive command to the low voltage Direct Current/Direct Current (DC/DC) converter. The low voltage Direct Current/Direct Current (DC/DC) converter is switched into Boost mode to stabilize/boost its output until the engine has started and system voltage regulation is established by the alternator. The converter provides the stabilized or boost output voltage until one of the following occurs:

  • Boost time exceeds 5 seconds
  • System input voltage exceeds targeted output

The Direct Current/Direct Current (DC/DC) converter control module has full bypass or stand-by mode functionality within an input of 6V-16V. The Direct Current/Direct Current (DC/DC) converter control module must be able to provide the boosted voltage with a minimum 6V power net input voltage. If the supply voltage goes outside the voltage range, the Direct Current/Direct Current (DC/DC) converter control module recovers without user intervention when the supply voltage returns to the normal operating range. The Direct Current/Direct Current (DC/DC) converter control module determines the stabilized output voltage to be targeted by continuously measuring the Direct Current/Direct Current (DC/DC) converter control module input voltage. Prior to the restart event, the Direct Current/Direct Current (DC/DC) converter control module receives the RE-CRANK signal and sets the boosted output voltage target to be equivalent to the measured input voltage. This makes sure the output voltage to the supported loads does not change.

Malfunction of the system does not lead to non-function of other vehicle systems. The system enters bypass mode if:

  • a thermal overload condition exists.
  • there is a Direct Current/Direct Current (DC/DC) converter control module failure.
  • the output voltage is more than 1V below input voltage and voltage boost is not available.

The Direct Current/Direct Current (DC/DC) converter control module self-protects against overheating and self-recovers without user interaction after an overheating event and is internally protected from short-circuits.

Component Description

The Direct Current/Direct Current (DC/DC) converter control module is connected in series between the high current fuse box and a select number of non-safety electrical loads. The majority of the loads are fused through the BCM and remaining loads are not fused and are switched on by a smart transistor located internal to the Direct Current/Direct Current (DC/DC) converter control module. The smart transistor acts as a fuse and shuts off power in the event of a short to ground. The Direct Current/Direct Current (DC/DC) converter control module has a dedicated body ground and incorporates a hardwired signal circuit from the PCM which notifies the Direct Current/Direct Current (DC/DC) converter control module prior to the engine cranking during an auto-start event.

    Direct Current/Direct Current (DC/DC) Converter Control Module - Overview. Description and Operation

    OVERVIEW The Low voltage Direct Current/Direct Current (DC/DC) converter, also known as the Voltage Quality Module (VQM), is on vehicles equipped with the auto-start-stop system...

    Direct Current/Alternating Current (DC/AC) Inverter. Diagnosis and Testing

    Inspection and Verification Before diagnosing or repairing the Direct Current/Alternating Current (DC/AC) Inverter system refer to the Owner's Literature and REFER to: Direct Current/Alternating Current (DC/AC) Inverter - System Operation and Component Description (414-05 Voltage Converter/Inverter, Description and Operation)...

    Other information:

    Lincoln Nautilus 2018-2022 Owners Manual: Phone


    Phone Precautions WARNING: Driving while distracted can result in loss of vehicle control, crash and injury. We strongly recommend that you use extreme caution when using any device that may take your focus off the road. Your primary responsibility is the safe operation of your vehicle...

    Lincoln Nautilus 2018-2022 Service Manual: Battery Disconnect and Connect. General Procedures


    Disconnect NOTICE: Removing the negative battery ground cable at the LH strut tower will not disable the vehicle's electrical system. Failure to disconnect the battery cable from the battery post may cause component damage. NOTE: When the battery is disconnected and connected, some abnormal drive symptoms may occur while the vehicle relearns its adaptive strategy...

    Categories

    Opening and Closing the Hood

    Opening the Hood

    Lincoln Nautilus. Opening and Closing the Hood

    Inside the vehicle, pull the hood release handle located under the left-hand side of the instrument panel.

    read more

    Copyright © 2022 www.linautilus.com