Honda Fit manuals

Honda Fit: Multiplex Integrated Control System Description

Second generation (2007-2024) / Honda Fit 2007-2024 Repair Manual / Electrical / Multiplex Integrated Control System Description

Body Controller Area Network (B-CAN) and Fast Controller Area Network (F-CAN)

The body controller area network (B-CAN) and the fast controller area network (F-CAN) share information between multiple electronic control units (ECUs). B-CAN communication moves at a slower speed (33.33 kbps) for convenience related items and for other functions. F-CAN information moves at a faster speed (500 kbps) for ‘‘real time'' functions such as fuel and emissions data. To allow both systems to share information, the gauge control module translates information from B-CAN to F-CAN and from F-CAN to B-CAN.This is called the Gateway Function.

· DATA LINK CONNECTOR (DLC)· SRS UNIT· VSA MODULATOR-CONTROL UNIT*1· YAW RATE ACCELERATIONSENSOR*1· ABS MODULATOR-CONTROL UNIT*2· AUDIO-NAVIGATION UNIT*3· EPS CONTROL UNIT· TPMS CONTROL UNIT(B-CAN)MICUF-CANTRANSCEIVERB-CANTRANSCEIVERIMMOBILIZER-KEYLESS CONTROLUNITHANDSFREELINKCONTROL UNIT*4F-CAN LF-CAN HECM/PCM(F-CAN)GAUGE CONTROL MODULEUNDER-DASHFUSE/RELAY BOX*1 : With VSA*2 : With ABS*3 : ‘12-13 models with navigation*4 : ‘12-13 models without navigation: CAN line

Gateway Function

The gauge control module acts as a gateway to allow both systems to share information. The gauge control module translates and relays the information from B-CAN to F-CAN and from F-CAN to B-CAN.

BATIG1F-CANTRANSCEIVERF-CAN HF-CANF-CAN LB-CANB-CANTRANSCEIVERGAUGE CONTROL MODULECPU (Has a built-in CAN controller)B-CAN

Network ‘‘Loss of Communication'' Error Checking Function

The ECUs on the CAN circuit send messages to each other. If there are any malfunctions on the network, the LCD display on the gauge control module can indicate the error messages by entering the gauge control module self-diagnostic function.

Self-diagnostic Function

By connecting the HDS to the data link connector (DLC), the HDS can retrieve the diagnostic information from the MICU via a diagnostic line called K-LINE. The K-LINE is separate from the CAN lines, and is connected to the CAN related ECUs. The MICU is a gateway between the HDS and B-CAN related ECUs, and it sends B-CAN diagnostic information to the HDS. When doing a function test with the HDS, the HDS sends an output signal through the K-LINE to the MICU. The MICU either relays the request to another ECU or commands the function itself.

F-CAN HF-CAN LB-CANIMMOBILIZER-KEYLESSCONTROL UNITMICUHDSDATA LINKCONNECTOR (DLC)(K-LINE)(K-LINE)ECM/PCMVSA MODULATOR-CONTROL UNIT*1YAW RATEACCELERATIONSENSOR*1ABS MODULATOR-CONTROL UNIT*2*1 : With VSA*2 : With ABS*3 : ‘09-11 models with navigation*4 : ‘12-13 models with navigation*5 : Without navigation*6 : ‘12-13 models without navigation: CAN line: Other communication lineGAUGE CONTROL MODULEF-CAN (500 kbps)B-CAN (33.33 kbps)AUDIO-NAVIGATIONUNIT*3AUDIO-NAVIGATIONUNIT*4AUDIO UNIT*5HANDSFREELINKCONTROL UNIT*6SRS UNITEPS CONTROL UNITTPMS CONTROLUNIT

Wake-up and Sleep Function

The multiplex integrated control system has wake-up and sleep functions to decrease parasitic draw on the battery when the ignition switch is at LOCK (0).

  • In the sleep mode, the multiplex integrated control system stops functioning (communication and CPU control) when it is not necessary for the system to operate.

  • As soon as any operation is requested (for example, a door is unlocked), the related control units in the sleep mode immediately wake-up and begin to function.

  • When the ignition switch is turned to LOCK (0) with all the doors and the tailgate closed, and the driver's door is opened then closed, there is a delay of about 40 seconds   before the control unit goes from the wake-up mode to the sleep mode.

  • The sleep mode will not function if any door or the tailgate is open or if a key is in the ignition switch.

  • Electrical draw is reduced from 200 mA to less than 35 mA when in sleep mode.

NOTE: Sleep and Wake-Up Mode Test.

Fail-Safe Function

To prevent improper operation, the MICU has a fail-safe function. In the fail-safe mode, the output signal is fixed when any part of the system malfunctions (for example, a faulty control unit or communication line).

Each control unit has a hardware fail-safe function that fixes the output signal when there is a CPU malfunction and a software fail-safe function that ignores the signal from a malfunctioning control unit, which allows the system to continue operating normally.

Hardware Fail-Safe Control

Fail-safe function

When a CPU problem or an abnormal power supply voltage is detected, the MICU moves to the hardware fail-safe mode, and each system output load is set to the pre-programmed fail-safe value.

Software Fail-Safe Control

When any of the data from the B-CAN circuit cannot be received within a specified time, or an unusual combination of data is recognized, the MICU moves to the software fail-safe mode. The data that cannot be received is forced to a pre-programmed   value.


Power Supply Voltage Monitoring Function

The MICU monitors the power supply voltage (back-up voltage). If the voltage drops below 10 V, the MICU will not store DTCs.

Input

Output

MICU

Battery voltage (VBU)

B-CAN

MICU (UNDER 10 V) message


Combination Light Switch

The MICU controls the lighting system based on input from the combination light switch.

Input

Output

MICU

IG1 power supply

Combination light switch (OFF)

Combination light switch (ON)

Combination light switch (PARKING)

Combination light switch (PASSING)

Combination light switch (DIMMER)

Headlights (LO)

Headlights (HI)

Side marker lights

Parking lights

Taillights

B-CAN

Combination light switch (PARKING) message

Combination light switch (HLLO) message

Combination light switch (HLHI) message

Combination light switch (PASSING) message


Fog Lights

The MICU controls the fog lights based on input signal from the fog light switch.

Input

Output

MICU

IG1 power supply

Combination light switch (OFF)

Combination light switch (ON)

Combination light switch (FOG)

Fog light relay

B-CAN

Combination light switch (FRFOG) message

RM (FRFOGRLY) message


Turn Signal/Hazard Warning Lights

The MICU controls the turn signal/hazard warning lights based on input from the turn signal switch and the hazard warning switch.

Input

Output

MICU

IG1 power supply

Hazard warning switch

Turn signal switch (LEFT)

Turn signal switch (RIGHT)

Turn signal lights (LEFT)

Turn signal lights (RIGHT)

B-CAN

MICU (HAZARDSW) message

MICU (TURNRLY) message

Turn signal switch (TURNL) message

Turn signal switch (TURNR) message


Entry Light

The MICU controls the interior lights based on input signals of each switch and B-CAN signals.

Input

Output

MICU

IG1 power supply

Ignition key switch

Driver's door switch

Front passenger's door switch

Left rear door switch

Right rear door switch

Driver's door lock knob switch (LOCK/UNLOCK)

Ceiling light

B-CAN

Keyless door lock signal


Cargo Area Light

The MICU controls the cargo area light based on the tailgate latch switch.

Input

Output

MICU

Tailgate latch switch

Cargo area light


Daytime Running Lights

The MICU controls the headlights as daytime running lights based on input from each switch and B-CAN signals.

Input

Output

MICU

IG2 power supply

Combination light switch (OFF)

Combination light switch (ON)

Combination light switch (PASSING)

Combination light switch (DIMMER)

Headlights (LO)

Headlights (HI)

Side maker lights

Taillights

B-CAN

Parking brake switch signal

   IG1 METER signal

RM (DRLKC) message

RM (DRLWRN) message


Windshield Wiper/Washer

The MICU controls the windshield wiper motor and windshield washer motor based on input signals from each switch and B-CAN signals.

Input

Output

MICU

IG1 power supply

Windshield Wiper switch (INT)

Windshield Wiper switch (LO)

Windshield Wiper switch (HI)

Windshield Wiper switch (MIST)

Windshield Washer switch

Windshield Wiper motor (AUTO STOP)

Brake pedal position switch

Transmission range switch (P) position (A/T)

Windshield Wiper motor (INT)

Windshield Wiper motor (LO)

Windshield Wiper motor (HI)

Windshield Washer motor

B-CAN

IG1 METER signal

Parking brake switch signal

Vehicle speed pulse signal

Windshield wiper switch (FRINT) message

Windshield wiper switch (FRWIPLO) message

Windshield wiper switch (FRWIPHI) message

Windshield washer switch (FRWASH) message

Windshield wiper switch (FRMIST) message

Windshield wiper motor (FRWIPAS) message


Rear Window Wiper/Washer

The MICU controls the rear window wiper motor and rear window washer motor based on inputs from each switch.

Input

Output

MICU

IG1 power supply

Rear window wiper motor switch

Rear window washer motor switch

Windshield washer switch

Windshield wiper switch (INT)

Windshield wiper switch (LO)

Windshield wiper switch (HI)

Back-up light switch (M/T)

Transmission range switch (R) position (A/T)

Rear window wiper motor

Rear window washer motor

B-CAN

Windshield washer switch (FRWASH) message

Rear window washer switch (RRWASH) message


Windshield/Rear Window Washer

The MICU controls the windsheild washer and the rear window washer motor based on inputs from each switch.

Input

Output

MICU

IG1 power supply

Windshield washer motor switch

Rear window washer motor switch

Rear window washer motor

Windshield washer motor

B-CAN

Windshield washer switch (FRWASH) message

Rear window washer switch (RRWASH) message


Power Window Timer (Key-Off Operation)

The MICU controls the power window key-off operation based on inputs from each switch.

Input

Output

MICU

IG1 power supply

Ignition key switch

Driver's door switch

Front passenger's door switch

Power window timer


Collision Detection Signal (CDS)

The MICU controls the door lock actuators based on the IG1 and SRS (CDS) inputs.

Input

Output

MICU

IG1 power supply

Door/Tailgate lock actuators (UNLOCK)

B-CAN

SRS (CDSFR) message

SRS (CDSSD) message

SRS (CDSRR) message

SRS (CDSRO) message


Power Door Locks

The MICU controls the door lock actuators based on inputs from each switch.

Input

Output

MICU

IG1 power supply

Ignition key switch

Driver's door switch

Front passenger's door switch

Left rear door switch

Right rear door switch

Tailgate latch switch

Driver's door lock switch (LOCK/UNLOCK)

Driver's door key cylinder switch (LOCK/UNLOCK)

Driver's door lock knob switch (LOCK/UNLOCK)

Door/Tailgate lock actuators (LOCK)

Door/Tailgate lock actuators (UNLOCK)

Keyless Entry System

The MICU controls the door lock actuators based on inputs of each switch.

Input

Output

MICU

IG1 power supply

Ignition key switch

Driver's door switch

Front passenger's door switch

Left rear door switch

Right rear door switch

Tailgate latch switch

Driver's door lock knob switch (LOCK/UNLOCK)

Driver's door lock switch (LOCK/UNLOCK)

Driver's door key cylinder switch (LOCK/UNLOCK)

Driver's door lock actuator (UNLOCK)

Door/Tailgate lock actuators (LOCK)

Door/Tailgate lock actuators (UNLOCK)

B-CAN

Keyless door lock signal

Relock message


Key Interlock (A/T)

The MICU controls the key interlock solenoid based on inputs from each switch.

Input

Output

MICU

Ignition switch (I)

Transmission range switch (P) position

Park-pin switch

Key interlock solenoid


Security Alarm System

The MICU controls the exterior lights and the horn based on inputs of each switch.

Input

Output

MICU

IG1 power supply

Ignition key switch

Audio switch

Tailgate latch switch

Driver's door switch

Front passenger's door switch

Left rear door switch

Right rear door switch

Driver's door key cylinder switch (LOCK/UNLOCK)

Driver's door lock knob switch (UNLOCK)

Front passenger's door lock knob switch (UNLOCK)

Left rear door lock knob switch (UNLOCK)

Right rear door lock knob switch (UNLOCK)

Security hood switch

Headlights (LO)

Parking lights

Side marker lights

Taillights

Security horn

B-CAN

Keyless door lock signal

Door lock signal

VALID CODE message

MICU (SET1) message

MICU (SET2) message

ALARM (ACTION) message


Answer Back Response Operation

The MICU controls the lighting system and horn based on keyless signals sent by B-CAN.

Input

Output

MICU

Horn

Headlights (LO)

Taillights

Side marker lights

Parking lights

B-CAN

Answer back (PARKING) signal

Answer back (HLLO) signal

Answer back (HORN) signal


Auto Door Lock

The MICU controls the door lock actuators based on inputs from each switch and B-CAN signals.

Input

Output

MICU

IG1 power supply

Driver's door switch

Front passenger's door switch

Left rear door switch

Right rear door switch

Tailgate latch switch

Driver's door lock knob switch (UNLOCK)

Front passenger's door lock knob switch (UNLOCK)

Left rear door lock knob switch (UNLOCK)

Right rear door lock knob switch (UNLOCK)

Transmission range switch (P) position (A/T)

Brake pedal position switch

Door/Tailgate lock actuators (LOCK)

B-CAN

Vehicle speed signal

Engine speed signal

Auto Door Unlocks

The MICU controls the door lock actuators based on the inputs from each switch.

Input

Output

MICU

IG1 power supply

Ignition key switch

Driver's door switch

Front passenger's door switch

Left rear door switch

Right rear door switch

Tailgate latch switch

Driver's door lock knob switch (UNLOCK)

Front passenger's door lock knob switch (UNLOCK)

Left rear door lock knob switch (UNLOCK)

Right rear door lock knob switch (UNLOCK)

Transmission range switch (P) position

Brake pedal position switch

Door/Tailgate lock actuators (UNLOCK)

Driver's door lock actuator (UNLOCK)

Keyless Panic Function

The MICU controls the keyless PANIC function based on Panic signals sent by B-CAN.

Input

Output

MICU

Headlights (LO)

Parking lights

Side marker lights

Taillights

Horn

B-CAN

PANIC singals


HDS Inputs and Function Tests

Certain inputs happen so quickly that the HDS cannot update fast enough. Hold the switch that is being tested while monitoring the Data List. This should give the HDS time to update the signal on the Data List.

Because the HDS software is updated to support the release for newer vehicles, it is not uncommon to see system function tests that are not supported.

Make sure that the most current HDS software is loaded.

Input

System Menu

Data List

Data List Indication

Lighting

Driver's Door Switch

OFF/ON

Hazard Warning Switch

OFF/ON

Headlight Switch (OFF)

OFF/ON

Headlight Switch (PARKING)

OFF/ON

Headlight Switch (HEADLIGHT)

OFF/ON

Headlight Switch (High Beam)

OFF/ON

Headlight Switch (PASSING)

OFF/ON

Turn Signal Switch (LEFT)

OFF/ON

Turn Signal Switch (RIGHT)

OFF/ON

Fog Light Switch

OFF/ON

Left Turn Signal Command

OFF/ON

Right Turn Signal Command

OFF/ON

Cargo Light Command

OFF/ON

Headlight Command

OFF/ON

Headlight High Beam Command

OFF/ON

Parking Light Command

OFF/ON

Fog Light Command

OFF/ON

DRL Command

OFF/ON


Input

System Menu

Data List

Data List Indication

Gauges

Cruise Control Main Switch (ACC switch)

OFF/ON

Cruise Control Set Switch

OFF/ON

Cruise Control Resume Switch

OFF/ON

Washer Fluid Level Switch

OFF/ON

Gauge Select/Reset Switch

OFF/ON

VSA off Switch

OFF/ON

Parking Brake Switch

OFF/ON

Brake Fluid Level Switch

OFF/ON

Fuel Sending Unit Input 1

V

Fuel Sending Unit Input 2

V

ABS Indicator

OFF/ON

EBD Indicator (Electronic Brake Distribution)

OFF/ON

Cruise Control Main Switch Indicator

OFF/ON

MIL Indicator

OFF/ON

VSA Off Indicator

OFF/ON

VSA Indicator

OFF/ON

DRL Indicator

OFF/ON

Low Oil Pressure Indicator

OFF/ON

Charging System Indicator

OFF/ON

Maintenance Minder Indicator

OFF/ON

High Beam Indicator

OFF/ON

Parking Light ON Indicator

OFF/ON

Low Fuel Warning Indicator

OFF/ON

Security Indicator

OFF/ON

Fog Light Indicator

OFF/ON

Seatbelt Indicator

OFF/ON

SRS Indicator

OFF/ON

Speed Indicator (km/h) Command

km/h/Fail

Speed Indicator (mph) Command

mile/h/Fail

Driver's Seat Belt Buckle Switch

OFF/ON

A/T Gear Position Switch (R)

OFF/ON

A/T Gear Position Switch (P)

OFF/ON


Input

System Menu

Data List

Data List Indication

Door Locks

Driver's Door Switch

OFF/ON

Front Passenger's Door Switch

OFF/ON

Driver's Rear Door Switch

OFF/ON

Passenger's Rear Door Switch

OFF/ON

Driver's Rear Door Lock Knob Switch (UNLOCK)

OFF/ON

Passenger's Rear Door Lock Knob Sw. (UNLOCK)

OFF/ON

Driver's Door Key Cylinder Switch (LOCK)

OFF/ON

Driver's Door Key Cylinder Switch (UNLOCK)

OFF/ON

Driver's Door Lock Switch (LOCK)

OFF/ON

Driver's Door Lock Switch (UNLOCK)

OFF/ON

Driver's Door Lock Knob Switch (LOCK)

OFF/ON

Driver's Door Lock Knob Switch (UNLOCK)

OFF/ON

Front Passenger's Door Lock Knob Sw. (UNLOCK)

OFF/ON

Door LOCK Command

OFF/ON

Door UNLOCK Command

OFF/ON

Wiper

Brake Pedal Position Switch

OFF/ON

Rear Wiper Auto Stop Switch

ON/OFF

Windshield Wiper Switch (LOW)

OFF/ON

Windshield Wiper Switch (HIGH)

OFF/ON

Windshield Wiper Switch (MIST)

OFF/ON

Rear Wiper Switch

OFF/ON

Windshield Wiper Switch (INT)

OFF/ON

Windshield Washer Switch

OFF/ON

Rear Washer Switch

OFF/ON

Windshield Wiper Motor PARK Switch

OFF/ON

Rear Wiper Command

OFF/ON

Rear Washer Command

OFF/ON

Windshield Wiper Motor HI Command

OFF/ON

Windshield Wiper Motor LO Command

OFF/ON

Windshield Washer Motor Command

OFF/ON

Keyless Transmitter

Driver's Door Switch

OFF/ON

Front Passenger's Door Switch

OFF/ON

Driver's Rear Door Switch

OFF/ON

Passenger's Rear Door Switch

OFF/ON

Front Passenger's Door Lock Knob Sw. (UNLOCK)

OFF/ON

Driver's Rear Door Lock Knob Switch (UNLOCK)

OFF/ON

Passenger's Rear Door Lock Knob Sw. (UNLOCK)

OFF/ON

Trunk Knob Sw. (UNLOCK)

OFF/ON

Trunk Key Cylinder (UNLOCK)

OFF/ON

Trunk Handle Switch

OFF/ON

Driver's Door Key Cylinder Switch (LOCK)

OFF/ON

Driver's Door Key Cylinder Switch (UNLOCK)

OFF/ON

Driver's Door Lock Switch (LOCK)

OFF/ON

Driver's Door Lock Switch (UNLOCK)

OFF/ON

Driver's Door Lock Knob Switch (LOCK)

OFF/ON

Driver's Door Lock Knob Switch (UNLOCK)

OFF/ON

Door LOCK Command

OFF/ON

Door UNLOCK Command

OFF/ON

Driver's Door LOCK Command

OFF/ON

Trunk Lid Release Command

OFF/ON


Input

System Menu

Data List

Data List Indication

Security

Ignition Key Cylinder Switch

OFF/ON

Driver's Door Switch

OFF/ON

Front Passenger's Door Switch

OFF/ON

Driver's Rear Door Switch

OFF/ON

Passenger's Rear Door Switch

OFF/ON

Trunk Lid/Tailgate Switch

OFF/ON

Front Passenger's Door Lock Knob Sw. (UNLOCK)

OFF/ON

Driver's Rear Door Lock Knob Switch (UNLOCK)

OFF/ON

Passenger's Rear Door Lock Knob Sw. (UNLOCK)

OFF/ON

Trunk Knob Sw. (UNLOCK)

OFF/ON

Trunk Key Cylinder (UNLOCK)

OFF/ON

Trunk Handle Switch

OFF/ON

Hazard warning switch

OFF/ON

Security Hood Switch

OFF/ON

Driver's Door Key Cylinder Switch (LOCK)

OFF/ON

Driver's Door Key Cylinder Switch (UNLOCK)

OFF/ON

Driver's Door Lock Switch (LOCK)

OFF/ON

Driver's Door Lock Switch (UNLOCK)

OFF/ON

Driver's Door Lock Knob Switch (LOCK)

OFF/ON

Driver's Door Lock Knob Switch (UNLOCK)

OFF/ON

Door LOCK Command

OFF/ON

Door UNLOCK Command

OFF/ON

Driver's Door UNLOCK Command (Individual)

OFF/ON

Trunk Lid Release Command

OFF/ON

Headlight Command

OFF/ON

Headlight High Beam Command

OFF/ON

Parking Light Command

OFF/ON

Horn Command

OFF/ON


HDS Inputs and Function Tests

Function Test

System Menu

HDS Description

Note

Door Locks

LOCK all doors

Outputs LOCK signal 1 time (for 0.6 seconds) to all door

UNLOCK driver's side door

Outputs UNLOCK signal 1 time (for 0.6 seconds) to driver's side door

UNLOCK all doors

Outputs UNLOCK signal 1 time (for 0.6 seconds) to all door

Lighting

Interior Light Command

Illuminates for 30 seconds

Left Turn Signal Command

Blinks for 5 seconds

Right Turn Signal Command

Blinks for 5 seconds

Hazard Flasher

Blinks turn signal (left and right) for 15 seconds

Headlight Command

Operates headlight (low) for 15 seconds

Headlight High Beam Command

Operates headlight (high) for 15 seconds

Parking Lights Command

Operates Parking Light for 15 seconds

Fog Light

Operates fog light for 15 seconds

Cargo Area Light

Illuminates for 30 seconds

Security

Horn Command

Operates horn for 1 second

Wiper

Windshield Wiper Motor Low Command

Operates windshield wiper for 5 seconds (low speed)

Windshield Wiper Motor High Command

Operates windshield wiper for 5 seconds (high speed)

Windshield Washer Command

Operates windshield washer for 5 seconds

Rear Wiper Motor

Operates for 5 seconds

Rear Wiper Washer

Operates for 5 seconds

See also:

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