A/C-ECU
HEATER, AIR CONDITIONING AND VENTILATION55-8
COMMUNICATION
A/C-ECU performs the signal transmission and
reception with each ECU via CAN (Controller Area
Network)*
1. Also, with the heater control panel, it
transmits and receives signals via serial communica
-
tion.
NOTE: : For details of CAN communication, refer to
GROUP 54C
− Controller Area Network P.54C-2.
CAN COMMUNICATION INPUT SIGNALS TABLE
DIAGNOSTIC FUNCTION
A/C-ECU has the following functions for easier sys-
tem checks.
•DIAGNOSTIC FUNCTION
•Service data output
•Actuator test
NOTE: For each item, refer to the Workshop Manual.
AC506202
ETACS-ECU Heater control panelSRS-ECU
Engine-ECU
Combination meter A/C-ECU
: Interactive communicationCAN communication
SERIAL communication
AC
SignalTransmitter ECU
Engine coolant temperature signalENGINE-ECU
Vehicle speed signal
Engine speed signal
Ambient temperature signalETACS-ECU
Wiper signal
Ignition key signal
Average ambient temperature signalCOMBINATION METER
BASE ENGINE
ENGINE MECHANICAL11A-10
CRANKSHAFT PULLEY
The pulley is made of cast iron.
The pulley portion has grooves for the V-ribbed belt
(with 6 crests).
The flange portion of the pulley has a timing mark
notch for checking the ignition timing.
A torsion damper has been adopted to reduce the
torsional vibration of the crankshaft, as well as to
dramatically reduce noise and vibration in the
high-speed range.
DRIVE PLATE
The drive plate is made of sheet metal.The drive plate is mounted with 7 bolts.
AK604551Timing markRubberAB
AK502496
Ring gear Drive plate
AD
AUTO-CRUISE CONTROL SYSTEM
ENGINE AND EMISSION CONTROL17-4
COMPONENTS AND FUNCTIONS
ComponentFunction
Accelerator pedal position sensor (APP sensor)Informs the ECM of the accelerator pedal
depression.
Auto-cruise control switch"ON/OFF" switchPower switch for auto-cruise control system.
"ACC/RES" switchVehicle speed is set with the "ACC/RES" switch and
"COAST/SET" switch.
"COAST/SET" switch
"CANCEL" switchCancels the cruise speed setting.
Cancel systemClutch switch
the clutch operation, the clutch pedal status is
detected.
Stoplight switch•Because the constant speed driving is canceled
by the brake operation, it detects the brake pedal
status.
•As for the stoplight switch, two built-in switches,
the stoplight switch which is also used for the
stoplight illumination and the brake switch which
is used exclusively for the auto-cruise control, are
integrated, and thus the reliability is enhanced.
Transmission range
switch
the selector lever operation, it detects the "N"
position.
"CRUISE" indicator lightThe light is included in the combination meter and
illuminates when the "ON/OFF" switch is pressed
(auto-cruise control system: ON).
Data link connectorIf the M.U.T.-III scan tool is connected, the input
check code from the ECM can be read.
Engine control module (ECM)•Based on the input signal from each sensor and
switch, it outputs the throttle opening instruction
signal to the TAC motor.
•Based on the input signal from each sensor and
switch, it outputs the transaxle control signal to
the TCM
•Based on the vehicle speed signal from the
vehicle speed sensor, it calculates the vehicle
speed
•Based on the secondary pulley speed sensor
signal from the TCM, it calculates the vehicle
speed
•Based on the selector lever "N" position signal of
the transmission range switch from the ECM, it
cancels constant speed driving.
•Outputs the ON/OFF signals of "CRUISE"
indicator light and auto-cruise control system.
•The diagnostic trouble code signal is sent to the
"CRUISE" indicator light.
•The input check code is sent to the data link
connector.
Throttle actuator control motor (TAC motor)The throttle valve opens and closes in response to
the throttle angle signal from the ECM.
AUTO-CRUISE CONTROL SYSTEM
ENGINE AND EMISSION CONTROL17-7
FAIL-SAFE FUNCTION
When any of the following conditions are satisfied,
the auto-cruise control system function is stopped
until the system returns to normal. Also, when any of
the conditions are satisfied during the constant
speed driving, the constant speed driving is can
-
celled immediately.
•An abnormality occurs to the auto-cruise control
switch.
•An abnormality occurs to the stoplight switch.
When any of the following conditions are satisfied,
stop the vehicle once and turn the ignition switch to
"LOCK" (OFF). Otherwise, even when the system
returns to normal, the auto-cruise control system
function will continue to be stopped. Also, when any
of the conditions are satisfied during the constant
speed driving, the constant speed driving is can
-
celled immediately.
•ECM abnormality
•TP sensor abnormality
•APP sensor abnormality
.
DIAGNOSIS FUNCTION
•The diagnostic trouble code check is possible
with the "CRUISE" indicator light.
•To facilitate the system check, check the service
data output with the M.U.T.-III.
NOTE: For diagnostic items, service data output
items, and check method, refer to the Service Man
-
ual.
IGNITION TIMING AND CONTROL FOR CURRENT CARRYING TIME
MULTIPORT FUEL SYSTEM (MFI)13A-37
2. Spark-advance control and current carrying
time control
.
[During start]
ECM initiates ignition at fixed ignition timing (5° BTDC) syn-
chronized with the crankshaft position sensor signal.
.
[During normal operation]
After determining the basic spark-advance based on the intake
air volume and engine speed, ECM makes compensations
based on input from various sensors to control the optimum
spark-advance and current carrying time.
List of main compensations for spark-advance control and current carrying time control
.
[Control for checking ignition timing]
During basic ignition timing set mode for M.U.T.-III actuator test
function, sparking is done with fixed ignition timing (5
° BTDC)
synchronized with crankshaft position sensor signal.
CompensationsContent
Intake air temperature compensationCompensation is made according to intake air
temperature. The higher the intake air temperature
the greater the delay in ignition timing.
Engine coolant temperature compensationCompensation is made according to engine coolant
temperature. The lower the engine coolant
temperature the greater the advance in ignition
timing.
Knocking compensationCompensation is made according to generation of
knocking. The greater the knocking the greater the
delay in ignition timing.
Stable idle compensationCompensation is made according to change in idle
speed. In case engine speed becomes lower than
target speed, ignition timing is advanced.
Delay compensation when changing shiftDuring change of shift, sparking is delayed
compared to normal ignition timing to reduce
engine output torque and absorb the shock of the
shift change.
Battery voltage compensationCompensation is made depending on battery
voltage. The lower the battery voltage the greater
the current carrying time and when battery voltage
is high current carrying time is shortened.
CONSTRUCTION DESCRIPTION
FOUR-WHEEL ANTI-LOCK BRAKE SYSTEM (4ABS)35B-11
NOTE: .
•*1 This diagnostic trouble code is not set within
the vehicle speed of 20 km/h (12 mph) or less.
•*2 Turns ON when two or more wheels are faulty.
•*3 Stays ON until the vehicle speed reaches 10
km/h (6 mph) when the ignition switch is turned to
ON next time.
DIAGNOSTIC FUNCTION
ABS-ECU has the following functions for easier sys-
tem checks. The following items can be diagnosed
using scan tool.
•Diagnostic trouble code set
•Service data output
•Actuator test.
DIAGNOSTIC TROUBLE CODE SET
There are 43 diagnosis items. Since all the diagnos-
tic results are recorded in volatile memory
(EEPROM*), they are stored in the memory even
though the battery terminals are disconnected.
NOTE: .
•*EEPROM (Electrical Erasable & Programmable
ROM): Special type of memory that can be pro
-
grammed or erased electrically
•For each diagnosis item, refer to Service Manual.
.
SERVICE DATA OUTPUT
Using scan tool, the input data sent from the sensors
and switches can be read.
NOTE: For service data items, refer to Service Man-
ual.
.
C2116Abnormality in pump motor
power supply voltageExecutedProhibitedExtinguishedIlluminated*3
C1000Abnormality in stop light switch
circuitExecutedExecutedExtinguishedExtinguished
C2200Abnormality in ABS-ECUProhibitedProhibitedIlluminatesIlluminates
C2100Battery
voltage
problem (low
voltage)9.7 ± 0.3 V or
less
*1
ExecutedProhibitedExtinguishedIlluminates
8.0 ± 0.5 V or
less
*1
ProhibitedProhibitedIlluminatesIlluminates
C2101Battery
voltage
problem (high
voltage)18.0 ± 1.0 V or
moreProhibitedProhibitedIlluminatesIlluminates
C1395Brake fluid filling not completedExecutedExecutedExtinguishedFlashes (1 Hz)
C2203VIN not writtenExecutedExecutedExtinguishedIlluminates
C1608Implausible diagnosis dataExecutedExecutedExtinguishedExtinguished
U0001Bus offExecutedExecutedExtinguishedExtinguished
U0100Engine time-out errorExecutedExecutedExtinguishedExtinguished
U0141ETACS time-out errorExecutedExecutedExtinguishedExtinguished
U1415Variant coding not implementedExecutedProhibitedExtinguishedIlluminates
U1417Invalid variant coding value
(including wrong assembly)ExecutedProhibitedExtinguishedIlluminates
DTC
No.Item Countermeasures for failure
EBD control ABS control Brake
warning lightABS warning
light