Mazda intelligent Drive Select (Mi-Drive) SYSTEM
id012200000300
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Warning
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• Do not drive on paved roads while off-road mode is selected. Otherwise, the powertrain related parts may be adversely affected which could lead to an accident.
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Caution
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• When driving on wet, snow bound, or icy roads, avoid the use of sport mode. Otherwise, the tires could slip.
• Mi-Drive may not operate correctly under the following conditions.
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― Tire tread pattern and manufacturer combination are different between front and rear tires
― Tire chains are installed
• Use off-road mode when driving on slippery roads such as muddy, sandy, or deep snowbound roads, and drive in normal mode during normal driving.
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Note
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• If the vehicle is driven continuously in off-road mode, the 4WD warning indication may be displayed.
• When off-road mode is operating or operable, vehicle vibration or operation noise may occur, but this does not indicate a malfunction.
Outline
• Mi-Drive is a system which can switch the vehicle drive mode according to the driving scenario and the road conditions.
• Optimum driving performance according to conditions can be operated by switching the drive mode.
• Selectable drive modes differ according to the vehicle specification and there are the following patterns.
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― Pattern A Normal mode/sport mode
― Pattern B Normal mode/off-road mode
― Pattern C Normal mode/sport mode/off-road mode
Construction
Block diagram
Function
• The following drive modes can be switched according to the conditions.
Normal mode
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― This mode is suitable for normal driving or gentle acceleration.
Sport mode
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― This mode enhances the vehicle response to the accelerator pedal operation compared to normal mode.
Off-road mode
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― This mode assures traction when driving on rough ground, improves driving stability, and assists in freeing tires that are stuck.
• The functions of each part related to the controls are indicated in the table.
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Part name
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Function
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PCM
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• Switches engine control according to selected drive mode
• Determines drive mode switching permission/hold based on PCM, TCM, DSC HU/CM conditions
• Sends necessary engine-related information for controls and drive mode switching permit/hold signal to instrument cluster
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DSC HU/CM
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• Switches brake control according to selected drive mode
• Sends necessary brake-related information for controls to PCM and instrument cluster
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TCM
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• Switches transaxle control according to selected drive mode
• Sends necessary transaxle-related information for controls to PCM
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4WD control module
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• Switches 4WD control according to selected drive mode
• Sends necessary 4WD-related information for controls to instrument cluster
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Mi-Drive switch
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• Selects drive mode by driver’s switch operation
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Instrument cluster
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• Detects Mi-Drive switch operation
• Switches drive mode and sends mode switching command to each control module
• Displays Mi-Drive operation conditions in instrument cluster
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Operation
Mi-Drive system transition diagram
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• Drive mode switching is performed by operating the Mi-Drive switch up and down.
Drive mode switching control
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1. When the Mi-Drive switch is operated, the instrument cluster detects the switch operation information.
2. The instrument cluster switches the drive mode based on the detected switch operation information and the drive mode switching permit/hold signal sent by the PCM.
3. When the drive mode is switched, the instrument cluster changes the display according to the drive mode.
4. The instrument cluster sends the drive mode switching command to each control module.
5. Each control module which has received a switching command changes the control content according to the drive mode as follows.
Sport mode
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Control module
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Changed content
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PCM
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• Increases required engine torque relative to amount of accelerator operation
• Switches G-vectoring control plus control to achieve both stability and steerability
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TCM
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• Selects lower gear and reduces unnecessary acceleration generation time due to shifting
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Off-road mode
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Control module
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Changed content
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PCM
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• Changes target acceleration MAP to gentle acceleration for improved acceleration performance on rough roads
• When driving on flat or up slopes, idling speed is increased for vehicle roll prevention and improved acceleration from a stop performance
• Engine torque coordinated control by AWD for drive stability and slipping suppression on low traction surfaces
• Switches G-vectoring control plus control to achieve both stability and steerability
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TCM
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• Performs optimum torque converter TCC control and shift pattern selection during off-road driving
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DSC HU/CM
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• Controls brake TCS during diagonally opposed wheel spin
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4WD control module
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• Provides pre-torque to electronic control coupling unit and increases torque distribution to rear wheels for improved handling stability when driving on unpaved roads
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Drive mode switching unavailable conditions
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• If any of the following conditions is met, the drive mode change is canceled even if the Mi-Drive switch is operated.
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― During sudden maneuvering
― During ABS/DSC/TCS control
― During initial check (if drive mode is switched between normal and off-road modes)
• When the drive mode switching unavailable conditions are met and the Mi-Drive switch is operated, the driver is notified that the drive mode switching is temporarily unavailable using the instrument cluster display and the notification sound.
Mi-Drive inhibition conditions
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• If any of the following conditions is met, the vehicle inhibits drive mode switching and forcibly switches to normal mode.
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― Vehicle malfunction (tire with differing diameter is installed)
― Malfunction or transmission error with control-related parts
― During constant speed control (sport mode only) using Mazda radar cruise control (MRCC) or cruising & traffic support (CTS)
• When the Mi-Drive inhibition conditions are met and the Mi-Drive switch is operated, the driver is notified that Mi-Drive is currently inhibited using the instrument cluster display and the notification sound.
