EC-530
[QR (WITH EURO-OBD)]
AUTOMATIC SPEED CONTROL DEVICE (ASCD)
COAST OPERATION
When the SET/COAST switch is pressed during cruise control driving, decrease vehicle set speed until the
switch is released. And then ASCD will keep the new set speed.
RESUME OPERATION
When the RESUME/ACCELERATE switch is pressed after cancel operation other than pressing MAIN switch
is performed, vehicle speed will return to last set speed. To resume vehicle set speed, vehicle condition must
meet following conditions.
Brake pedal is fully released
Clutch pedal is fully released (M/T models)
A/T selector lever is in other than P and N position (A/T models)
Vehicle speed is greater than 40 km/h (25 MPH) and less than 144 km/h (89 MPH)
Component DescriptionEBS01FAY
ASCD STEERING SWITCH
Refer to EC-377 .
ASCD BRAKE SWITCH
Refer to EC-387 and EC-506 .
ASCD CLUTCH SWITCH
Refer to EC-387 and EC-506
STOP LAMP SWITCH
Refer to EC-387 , EC-405 and EC-506 .
ELECTRIC THROTTLE CONTROL ACTUATOR
Refer to EC-294 , EC-296 , EC-306 and EC-314 .
ASCD INDICATOR
Refer to EC-514 .
ENGINE CONTROL SYSTEM
EC-549
[QR (WITHOUT EURO-OBD)]
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MIXTURE RATIO FEEDBACK CONTROL (CLOSED LOOP CONTROL)
The mixture ratio feedback system provides the best air-fuel mixture ratio for driveability and emission control.
The three way catalyst (manifold) can then better reduce CO, HC and NOx emissions. This system uses
heated oxygen sensor 1 in the exhaust manifold to monitor whether the engine operation is rich or lean. The
ECM adjusts the injection pulse width according to the sensor voltage signal. For more information about
heated oxygen sensor 1, refer to EC-666, "
DTC P0132 HO2S1" . This maintains the mixture ratio within the
range of stoichiometric (ideal air-fuel mixture).
This stage is referred to as the closed loop control condition.
Heated oxygen sensor 2 is located downstream of the three way catalyst (manifold). Even if the switching
characteristics of heated oxygen sensor 1 shift, the air-fuel ratio is controlled to stoichiometric by the signal
from heated oxygen sensor 2.
Open Loop Control
The open loop system condition refers to when the ECM detects any of the following conditions. Feedback
control stops in order to maintain stabilized fuel combustion.
Deceleration and acceleration
High-load, high-speed operation
Malfunction of heated oxygen sensor 1 or its circuit
Insufficient activation of heated oxygen sensor 1 at low engine coolant temperature
High engine coolant temperature
During warm-up
After shifting from N to D (A/T models)
When starting the engine
MIXTURE RATIO SELF-LEARNING CONTROL
The mixture ratio feedback control system monitors the mixture ratio signal transmitted from heated oxygen
sensor 1. This feedback signal is then sent to the ECM. The ECM controls the basic mixture ratio as close to
the theoretical mixture ratio as possible. However, the basic mixture ratio is not necessarily controlled as orig-
inally designed. Both manufacturing differences (i.e., mass air flow sensor hot wire) and characteristic
changes during operation (i.e., injector clogging) directly affect mixture ratio.
Accordingly, the difference between the basic and theoretical mixture ratios is monitored in this system. This is
then computed in terms of “injection pulse duration” to automatically compensate for the difference between
the two ratios.
“Fuel trim” refers to the feedback compensation value compared against the basic injection duration. Fuel trim
includes short term fuel trim and long term fuel trim.
“Short term fuel trim” is the short-term fuel compensation used to maintain the mixture ratio at its theoretical
value. The signal from heated oxygen sensor 1 indicates whether the mixture ratio is RICH or LEAN compared
to the theoretical value. The signal then triggers a reduction in fuel volume if the mixture ratio is rich, and an
increase in fuel volume if it is lean.
“Long term fuel trim” is overall fuel compensation carried out long-term to compensate for continual deviation
of the short term fuel trim from the central value. Such deviation will occur due to individual engine differences,
wear over time and changes in the usage environment.
PBIB0121E
TROUBLE DIAGNOSIS
EC-611
[QR (WITHOUT EURO-OBD)]
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*: For QR25DE engine models
NOTE:
Any monitored item that does not match the vehicle being diagnosed is deleted from the display automatically.
DATA MONITOR (SPEC) MODE
Monitored Item
NOTE:
Any monitored item that does not match the vehicle being diagnosed is deleted from the display automatically.AT OD MONITOR*
[ON/OFF]
Indicates [ON/OFF] condition of A/T O/D
according to the input signal from the TCM.For M/T models, always “OFF” is
displayed.
AT OD CANCEL*
[ON/OFF]
Indicates [ON/OFF] condition of A/T O/D can-
cel signal sent from the TCM.For M/T models, always “OFF” is
displayed.
CRUISE LAMP*
[ON/OFF]
Indicates [ON/OFF] condition of CRUISE lamp
determined by the ECM according to the input
signals.
SET LAMP*
[ON/OFF]
Indicates [ON/OFF] condition of SET lamp
determined by the ECM according to the input
signals.
Voltage [V]
Voltage, frequency, duty cycle or pulse width
measured by the probe.
Only “#” is displayed if item is
unable to be measured.
Figures with “#”s are temporary
ones. They are the same figures
as an actual piece of data which
was just previously measured. Frequency
[msec], [Hz] or [%]
DUTY-HI
DUTY-LOW
PLS WIDTH-HI
PLS WIDTH-LOW Monitored item [Unit]ECM
INPUT
SIGNALSMAIN
SIG-
NALSDescription Remarks
Monitored item [Unit]ECM
INPUT
SIGNALSMAIN
SIGNALSDescription Remarks
ENG SPEED [rpm]×
Indicates the engine speed computed
from the signals of the crankshaft posi-
tion sensor (POS) and camshaft position
sensor (PHASE).
MAS A/F SE-B1 [V]××
The signal voltage of the mass air flow
sensor specification is displayed.When engine is running specification
range is indicated.
B/FUEL SCHDL
[msec]
“Base fuel schedule” indicates the fuel
injection pulse width programmed into
ECM, prior to any learned on board cor-
rection.
When engine is running specification
range is indicated.
A/F ALPHA-B1 [%]×
The mean value of the air-fuel ratio feed-
back correction factor per cycle is indi-
cated.When engine is running specification
range is indicated.
This data also includes the data for
the air-fuel ratio learning control.
TROUBLE DIAGNOSIS
EC-613
[QR (WITHOUT EURO-OBD)]
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EC
REAL TIME DIAGNOSIS IN DATA MONITOR MODE (RECORDING VEHICLE DATA)
Description
CONSULT-II has two kinds of triggers and they can be selected by touching “SETTING” in “DATA MONITOR”
mode.
1. “AUTO TRIG” (Automatic trigger):
The malfunction will be identified on the CONSULT-II screen
in real time.
In other words, DTC/1st trip DTC and malfunction item will be
displayed if the malfunction is detected by ECM.
At the moment a malfunction is detected by ECM, “MONI-
TOR” in “DATA MONITOR” screen is changed to “Recording
Data ... xx%” as shown at right, and the data after the mal-
function detection is recorded. Then when the percentage
reached 100%, “REAL-TIME DIAG” screen is displayed. If
“STOP” is touched on the screen during “Recording Data ...
xx%”, “REAL-TIME DIAG” screen is also displayed.
The recording time after the malfunction detection and the
recording speed can be changed by “TRIGGER POINT” and
“Recording Speed”. Refer to CONSULT-II Operation Manual.
2. “MANU TRIG” (Manual trigger):
DTC/1st trip DTC and malfunction item will not be displayed
automatically on CONSULT-II screen even though a malfunc-
tion is detected by ECM.
DATA MONITOR can be performed continuously even though
a malfunction is detected.
Operation
1. “AUTO TRIG”
While trying to detect the DTC/1st trip DTC by performing the DTC Confirmation Procedure, be sure to
select to “DATA MONITOR (AUTO TRIG)” mode. You can confirm the malfunction at the moment it is
detected.
While narrowing down the possible causes, CONSULT-II should be set in “DATA MONITOR (AUTO
TRIG)” mode, especially in case the incident is intermittent.
When you are inspecting the circuit by gently shaking (or twisting) the suspicious connectors, compo-
nents and harness in the “DTC Confirmation Procedure”, the moment a malfunction is found the DTC/
1st trip DTC will be displayed. (Refer to “Incident Simulation Tests” in GI-23, "
How to Perform Efficient
Diagnosis for an Electrical Incident" .)
2. “MANU TRIG”
If the malfunction is displayed as soon as “DATA MONITOR” is selected, reset CONSULT-II to “MANU
TRIG”. By selecting “MANU TRIG” you can monitor and store the data. The data can be utilized for fur-
ther diagnosis, such as a comparison with the value for the normal operating condition.
SEF705Y
SEF707X
EC-780
[QR (WITHOUT EURO-OBD)]
DTC P1564 ASCD STEERING SWITCH
DTC P1564 ASCD STEERING SWITCHPFP:25551
Component DescriptionEBS01FB3
ASCD steering switch has variant values of electrical resistance for each button. ECM reads voltage variation
of switch, and determines which button is operated.
Refer to EC-969, "
AUTOMATIC SPEED CONTROL DEVICE (ASCD)" for the ASCD function.
CONSULT-II Reference Value in Data Monitor ModeEBS01FB4
Specification data are reference values.
On Board Diagnosis LogicEBS01FB5
This self-diagnosis has the one trip detection logic.
The MI will not light up for this diagnosis.
NOTE:
If DTC P1564 is displayed with DTC P0605, first perform the trouble diagnosis for DTC P0605.
Refer to EC-716, "
DTC P0605 ECM".
1. ASCD steering switch 2. RESUME/ACCELERATE switch 3. CANCEL switch
4. SET/COAST switch 5. MAIN switch
PBIB2877E
MONITOR ITEM CONDITION SPECIFICATION
MAIN SW
Ignition switch: ONMAIN switch: Pressed ON
MAIN switch: Released OFF
CANCEL SW
Ignition switch: ONCANCEL switch: Pressed ON
CANCEL switch: Released OFF
RESUME/ACC SW
Ignition switch: ONRESUME/ACCELERATE switch:
PressedON
RESUME/ACCELERATE switch:
ReleasedOFF
SET SW
Ignition switch: ON SET/COAST switch: Pressed ON
SET/COAST switch: Released OFF
DTC No.Trouble Diagnosis
NameDTC Detecting Condition Possible Cause
P1564
1564ASCD steering
switch
An excessively high voltage signal from the ASCD
steering switch is sent to ECM.
ECM detects that input signal from the ASCD
steering switch is out of the specified range.
ECM detects that the ASCD steering switch is
stuck ON.
Harness or connectors
(The switch circuit is open or shorted.)
ASCD steering switch
ECM
EC-790
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DTC P1572 ASCD BRAKE SWITCH
DTC P1572 ASCD BRAKE SWITCHPFP:25320
Component DescriptionEBS01FBA
When the brake pedal is depressed, ASCD brake switch is turned
OFF and stop lamp switch is turned ON. ECM detects the state of
the brake pedal by this input of two kinds (ON/OFF signal).
Refer to EC-969, "
AUTOMATIC SPEED CONTROL DEVICE
(ASCD)" for the ASCD function.
CONSULT-II Reference Value in Data Monitor ModeEBS01FBB
Specification data are reference values.
On Board Diagnosis LogicEBS01FBC
This self-diagnosis has the one trip detection logic.
The MI will not light up for this diagnosis.
NOTE:
If DTC P1572 is displayed with DTC P0605, first perform the trouble diagnosis for DTC P0605.
Refer to EC-716, "
DTC P0605 ECM".
This self-diagnosis has the one trip detection logic. When malfunction A is detected, DTC is not
stored in ECM memory. And in that case, 1st trip DTC and 1st trip freeze frame data are displayed.
1st trip DTC is erased when ignition switch OFF. And even when malfunction A is detected in two
consecutive trips, DTC is not stored in ECM memory.
SEC009D
MONITOR ITEM CONDITION SPECIFICATION
BRAKE SW1
(ASCD brake switch)
Ignition switch: ONClutch pedal (M/T) and brake pedal:
Fully releasedON
Clutch pedal (M/T) and/or brake pedal:
Slightly depressedOFF
BRAKE SW2
(Stop lamp switch)
Ignition switch: ONBrake pedal: Fully released OFF
Brake pedal: Slightly depressed ON
DTC No.Trouble Diagnosis
NameDTC Detecting Condition Possible Cause
P1572
1572ASCD brake switchA)When the vehicle speed is above 30km/h
(19 MPH), ON signals from the stop lamp
switch and the ASCD brake switch are sent
to ECM at the same time.
Harness or connectors
(The stop lamp switch circuit is shorted.)
Harness or connectors
(The ASCD brake switch circuit is shorted.)
Harness or connectors
(The ASCD clutch switch circuit is shorted.)
(M/T models)
Stop lamp switch
ASCD brake switch
ASCD clutch switch
(M/T models)
Incorrect stop lamp switch installation
Incorrect ASCD brake switch installation
Incorrect ASCD clutch switch installation
(M/T models)
ECM B)ASCD brake switch signal is not sent to
ECM for extremely long time while the vehi-
cle is driving
EC-800
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DTC P1574 ASCD VEHICLE SPEED SENSOR
DTC P1574 ASCD VEHICLE SPEED SENSORPFP:31036
Component DescriptionEBS01FBI
ECM receives two vehicle speed sensor signals via CAN communication line. One is sent from ESP/TCS/ABS
control unit (models with ESP) or “ABS actuator and electric unit (control unit)”(models without ESP), and the
other is from TCM (Transmission control module).
The ECM uses these signals for ASCD control. Refer to EC-969, "
AUTOMATIC SPEED CONTROL DEVICE
(ASCD)" for ASCD functions.
On Board Diagnosis LogicEBS01FBJ
This self-diagnosis has the one trip detection logic.
The MI will not light up for this diagnosis.
NOTE:
If DTC P1574 is displayed with DTC U1000 or U1001, first perform the trouble diagnosis for DTC
U1000, U1001. Refer to EC-633, "
DTC U1000, U1001 CAN COMMUNICATION LINE" .
If DTC P1574 is displayed with DTC P0500, first perform the trouble diagnosis for DTC P0500.
Refer to EC-709, "
DTC P0500 VSS" .
If DTC P1574 is displayed with DTC P0605, first perform the trouble diagnosis for DTC P0605.
Refer to EC-716, "
DTC P0605 ECM" .
DTC Confirmation ProcedureEBS01FBK
CAUTION:
Always drive vehicle at a safe speed.
NOTE:
If DTC Confirmation Procedure has been previously conducted, always turn ignition switch OFF and wait at
least 10 seconds before conducting the next test.
TESTING CONDITION:
Step 3 may be conducted with the drive wheels lifted in the shop or by driving the vehicle. If a road test
is expected to be easier, it is unnecessary to lift the vehicle.
DTC No.Trouble Diagnosis
NameDTC Detecting Condition Possible Cause
P1574
1574ASCD vehicle speed
sensorECM detects a difference between two vehicle
speed signals is out of the specified range.
Harness or connectors
(The CAN communication line is open or
shorted)
Harness or connectors
(Revolution sensor circuit is open or shorted)
Harness or connectors
(Wheel sensor circuit is open or shorted.)
TCM
ESP/TCS/ABS control unit (models with ESP)
“ABS actuator and electric unit (control unit)”
(models without ESP)
Combination meter
Wheel sensor
Revolution sensor
ECM
EC-946
[QR (WITHOUT EURO-OBD)]
ASCD BRAKE SWITCH
ASCD BRAKE SWITCHPFP:25320
Component DescriptionEBS01FBP
When the brake pedal is depressed, ASCD brake switch is turned
OFF and stop lamp switch is turned ON. ECM detects the state of
the brake pedal by this input of two kinds (ON/OFF signal).
Refer to EC-969, "
AUTOMATIC SPEED CONTROL DEVICE
(ASCD)" for the ASCD function.
CONSULT-II Reference Value in Data Monitor ModeEBS01FBQ
Specification data are reference values.
SEC009D
MONITOR ITEM CONDITION SPECIFICATION
BRAKE SW1
(ASCD brake switch)
Ignition switch: ONClutch pedal (M/T) and brake pedal:
Fully releasedON
Clutch pedal (M/T) and/or brake pedal:
Slightly depressedOFF
BRAKE SW2
(Stop lamp switch)
Ignition switch: ONBrake pedal: Fully released OFF
Brake pedal: Slightly depressed ON