EC-660
[YD]
ENGINE CONTROL SYSTEM
System Chart
EBS0037B
Fuel Injection Control SystemEBS0036G
SYSTEM DESCRIPTION
Three types of fuel injection control are provided to accommodate engine operating conditions; normal control,
idle control and start control. The ECM determines the appropriate fuel injection control. Under each control,
the amount of fuel injected is adjusted to improve engine performance.
Pulse signals are exchanged between ECM and Electronic Drive Unit (EDU). EDU controls fuel injectors
according to the input signals to adjust the amount of fuel injected to the preset value.
START CONTROL
Input/Output Signal Chart
When the ECM receives a start signal from the ignition switch, the
ECM adapts the fuel injection system for the start control. The
amount of fuel injected at engine starting is a preset program value
in the ECM. The program is determined by the engine speed, engine
coolant temperature and common rail fuel pressure.
For better startability under cool engine conditions, the lower the
coolant temperature becomes, the greater the amount of fuel
injected. The ECM ends the start control when the engine speed
reaches the specific value, and shifts the control to the normal or idle
control.
Input (Sensor) ECM Function Output (Actuator)
lAccelerator pedal position sensor
lAccelerator pedal released position switch
lCommon rail fuel pressure sensor
lFuel temperature sensor
lEngine coolant temperature sensor
lCrankshaft position sensor (TDC)
lCamshaft position sensor
lVehicle speed sensor
lIgnition switch
lStop Lamp switch
lAir conditioner switch
lMass air flow sensor
lPark/neutral position switch
lBattery voltage
lPower steering oil pressure switchFuel injection controlEDU, Fuel injectors and Suction control
valve
Fuel injection timing controlEDU, Fuel injectors and Suction control
valve
Fuel cut controlEDU, Fuel injectors and Suction control
valve
Glow control system Glow relay & glow indictor lamp
On board diagnostic system Malfunction indicator (MI)
EGR volume control EGR volume control valve
Cooling fan control Cooling fan relay
Air conditioning cut control Air conditioner relay
Sensor Input Signal to ECM ECM Function Actuator
Engine coolant temperature sensor Engine coolant temperature
Fuel injection
control (start
control)EDU
Fuel injectors
Suction control valve Crankshaft position sensor (TDC) Engine speed
Camshaft position sensor Piston position
Ignition switch Start signal
Common rail fuel pressure sensor Common rail fuel pressure
SEF648S
ENGINE CONTROL SYSTEM
EC-661
[YD]
C
D
E
F
G
H
I
J
K
L
MA
EC
IDLE CONTROL
Input/Output Signal Chart
When the ECM determines that the engine speed is at idle, the fuel injection system is adapted for the idle
control. The ECM regulates the amount of fuel injected corresponding to changes in load applied to the engine
to keep engine speed constant. The ECM also provides the system with a fast idle control in response to the
engine coolant temperature signal.
NORMAL CONTROL
Input/Output Signal Chart
The amount of fuel injected under normal driving conditions is deter-
mined according to sensor signals. The crankshaft position sensor
(TDC) detects engine speed, the accelerator pedal position sensor
detects accelerator pedal position and common rail fuel pressure
sensor detects common rail fuel pressure. These sensors send sig-
nals to the ECM.
The fuel injection data, predetermined by correlation between vari-
ous engine speeds, accelerator pedal positions and common rail fuel
pressure are stored in the ECM memory, forming a map. The ECM
determines the optimal amount of fuel to be injected using the sen-
sor signals in comparison with the map.
MAXIMUM AMOUNT CONTROL
Input/Output Signal Chart
The maximum injection amount is controlled to an optimum by the engine speed, intake air amount, engine
coolant temperature, and accelerator opening in accordance with the driving conditions.
This prevents the oversupply of the injection amount caused by decreased air density at a high altitude or dur-
ing a system failure.
Sensor Input Signal to ECM ECM Function Actuator
Engine coolant temperature sensor Engine coolant temperature
Fuel injection
control (Idle
control)EDU
Fuel injectors
Suction control valve Crankshaft position sensor (TDC) Engine speed
Battery Battery voltage
Accelerator pedal position sensor Accelerator pedal position
Accelerator pedal released position switch Accelerator pedal released position
Vehicle speed sensor Vehicle speed
Air conditioner switch Air conditioner signal
Common rail fuel pressure sensor Common rail fuel pressure
Sensor Input Signal to ECM ECM Function Actuator
Crankshaft position sensor (TDC) Engine speed
Fuel injection
control (Nor-
mal control)EDU
Fuel injectors
Suction control valve Accelerator pedal position sensor Accelerator position
Common rail fuel pressure sensor Common rail fuel pressure
SEF649S
Sensor Input Signal to ECM ECM Function Actuator
Mass air flow sensor Amount of intake air
Fuel injection
control (Maxi-
mum amount
control)EDU
Fuel Injectors Engine coolant temperature sensor Engine coolant temperature
Crankshaft position sensor (TDC) Engine speed
Accelerator pedal position sensor Accelerator position
EC-662
[YD]
ENGINE CONTROL SYSTEM
DECELERATION CONTROL
Input/Output Signal Chart
The ECM sends a fuel cut signal to the fuel injector and suction control valve during deceleration for better fuel
efficiency. The ECM determines the time of deceleration according to signals from the accelerator pedal
released position switch and crankshaft position sensor (TDC).
Fuel Injection Timing Control SystemEBS0036H
DESCRIPTION
The target fuel injection timing in accordance with the engine speed and the fuel injection amount are recorded
as a map in the ECM beforehand. The ECM determines the optimum injection timing using sensor signals
accordance with the map.
Air Conditioning Cut ControlEBS0036I
INPUT / OUTPUT SIGNAL CHART
SYSTEM DESCRIPTION
This system improves acceleration when the air conditioner is used.
When the accelerator pedal is fully depressed, the air conditioner is turned off for a few seconds.
When engine coolant temperature becomes excessively high, the air conditioner is turned off. This continues
until the engine coolant temperature returns to normal.
Fuel Cut Control (At No Load & High Engine Speed)EBS0036J
INPUT/OUTPUT SIGNAL CHART
If the engine speed is above 2,800 rpm with no load (for example, in neutral and engine speed over 2,800
rpm) fuel will be cut off after some time. The exact time when the fuel is cut off varies based on engine speed.
Fuel cut will operate until the engine speed reaches 1,500 rpm, then fuel cut is cancelled.
NOTE:
This function is different from deceleration control listed underEC-660, "
Fuel Injection Control Sys-
tem".
Sensor Input Signal to ECM ECM Function Actuator
Accelerator pedal released position switch Accelerator pedal position Fuel injection
control (Decel-
eration control)EDU
Fuel injectors
Crankshaft position sensor (TDC) Engine speed
Sensor Input Signal to ECM ECM Function Actuator
Air conditioner switch Air conditioner “ON” signal
Air conditioner
cut controlAir conditioner relay Accelerator pedal position sensor Accelerator pedal opening angle
Vehicle speed sensor Vehicle speed
Engine coolant temperature sensor Engine coolant temperature
Sensor Input Signal to ECM ECM Function Actuator
Vehicle speed sensor Vehicle speed
Fuel cut controlEDU
Fuel injectors Accelerator pedal released position switch Accelerator position
Crankshaft position sensor (TDC) Engine speed
EC-664
[YD]
BASIC SERVICE PROCEDURE
BASIC SERVICE PROCEDURE
PFP:00018
Fuel FilterEBS0036N
DESCRIPTION
A water draining cock is on the lower side and a priming pump for bleeding air is on the upper side.
AIR BLEEDING
Pump the priming pump to bleed air.
lWhen air is bled completely, the pumping of the priming pump
suddenly becomes heavy. Stop the operation at that time.
lIf it is difficult to bleed air by the pumping of the priming pump
(the pumping of the priming pump does not become heavy), dis-
connect the fuel supply hose between the fuel filter and the fuel
gallery. Then, perform the operation described above, and make
sure that fuel comes out. (Use a pan, etc. so as not to spill fuel.
Do not let fuel get on engine and other parts.) After that, connect
the hose, then bleed air again.
lStart engine and let it idle for at least one minute after perform-
ing air bleeding.
WATER DRAINING
1. Remove the fuel filter, filter bracket, protector assembly from the dash panel as follows.
a. Remove the air cleaner case (upper), air duct assembly, and vacuum hose for brake booster (between the
vacuum pump and vacuum pipe).
CAUTION:
After the duct is removed, cover the opening with gum tape, etc. to prevent foreign object from
getting into the engine during the operation.
b. Remove the mounting nuts on the dash panel, then remove the fuel filter, filter bracket, and protector
assembly from the dash panel.
lIt is not necessary to disconnect the fuel hose.
2. Using a tool such as a pliers, loosen the water draining cock at the bottom of the fuel filter.
Accelerator Pedal Released Position LearningEBS009NW
DESCRIPTION
"Accelerator Pedal Released Position Learning" is an operating to learn the fully released position of the
accelerator pedal by monitoring the accelerator pedal position sensor output signal. It must be performed
when accelerator work unit or ECM is replaced.
OPERATION PROCEDURE
1. Turn ignition switch "ON".
2. Select "OFF ACCEL PO SIG" in "ACTIVE TEST" mode with
CONSULT-II
3. Make sure that accelerator pedal is released.
SEF375Y
PBIB0411E
TROUBLE DIAGNOSIS
EC-669
[YD]
C
D
E
F
G
H
I
J
K
L
MA
EC
TROUBLE DIAGNOSISPFP:00004
Trouble Diagnosis IntroductionEBS0036Z
INTRODUCTION
The engine has an ECM to control major systems such as fuel injec-
tion control, fuel injection timing control, glow control system, etc.
The ECM accepts input signals from sensors and instantly actuators.
It is essential that both input and output signals are proper and sta-
ble. At the same time, it is important that there are no problems such
as vacuum leaks, or other problems with the engine.
It is much more difficult to diagnose a problem that occurs intermit-
tently rather than continuously. Most intermittent problems are
caused by poor electric connections or improper wiring. In this case,
careful checking of suspected circuits may help prevent the replace-
ment of good parts.
A visual check only may not find the cause of the problems. A road
test with CONSULT-II or a circuit tester connected should be per-
formed. Follow theEC-670, "
WORK FLOW".
Before undertaking actual checks, take a few minutes to talk with a
customer who approaches with a driveability complaint. The cus-
tomer can supply good information about such problems, especially
intermittent ones. Find out what symptoms are present and under
what conditions they occur. A “Diagnostic Worksheet” like the exam-
ple on next page should be used.
Start your diagnosis by looking for “conventional” problems first. This
will help troubleshoot driveability problems on an electronically con-
trolled engine vehicle.
MEF036D
SEF233G
SEF234G
TROUBLE DIAGNOSIS
EC-671
[YD]
C
D
E
F
G
H
I
J
K
L
MA
EC
Description for Work Flow
DIAGNOSTIC WORK SHEET
There are many operating conditions that lead to the malfunction of
engine components. A good grasp of such conditions can make trou-
bleshooting faster and more accurate.
In general, each customer feels differently about a problem. It is
important to fully understand the symptoms or conditions for a cus-
tomer complaint.
Utilize a diagnostic worksheet like the one shown below in order to
organize all the information for troubleshooting.
STEP DESCRIPTION
STEP IGet detailed information about the conditions and the environment when the incident/symptom occurred using the
EC-671, "
DIAGNOSTIC WORK SHEET".
STEP IIBefore confirming the concern, check and write down (print out using CONSULT-II) the DTC, then erase the DTC.
Refer toEC-666
.
If the incident cannot be verified, performEC-699, "
TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT".
Study the relationship between the cause, specified by DTC, and the symptom described by the customer. (The
“Symptom Matrix Chart” will be useful. Refer toEC-676
.) Also check related service bulletins for information.
STEP IIITry to confirm the symptom and under what conditions the incident occurs.
The “DIAGNOSTIC WORK SHEET” is useful to verify the incident. Connect CONSULT-II to the vehicle in DATA
MONITOR (AUTO TRIG) mode and check real time diagnosis results.
If the incident cannot be verified, performEC-699, "
TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT".
If the malfunction code is detected, skip STEP IV and perform STEP V.
STEP IVTry to detect the DTC by driving in (or performing) the “DTC Confirmation Procedure”. Check and read the DTC by
using CONSULT-II.
During the DTC verification, be sure to connect CONSULT-II to the vehicle in DATA MONITOR (AUTO TRIG) mode
and check real time diagnosis results.
If the incident cannot be verified, performEC-699, "
TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT".
In case the “DTC Confirmation Procedure” is not available, perform the “Overall Function Check” instead. The DTC
cannot be displayed by this check, however, this simplified “check” is an effective alternative.
The “NG” result of the “Overall Function Check” is the same as the DTC detection.
STEP VTake the appropriate action based on the results of STEP I through IV.
If the malfunction code is indicated, proceed to Trouble Diagnosis for DTC PXXXX.
If the normal code is indicated, proceed to the Basic Inspection,EC-672
. Then perform inspections according to the
Symptom Matrix Chart. Refer toEC-676
.
STEP VIIdentify where to begin diagnosis based on the relationship study between symptom and possible causes. Inspect the
system for mechanical binding, loose connectors or wiring damage using (tracing) “Harness Layouts”.
Gently shake the related connectors, components or wiring harness with CONSULT-II set in “DATA MONITOR (AUTO
TRIG)” mode.
Check the voltage of the related ECM terminals or monitor the output data from the related sensors with CONSULT-II.
Refer toEC-685
orEC-696.
The “Diagnostic Procedure” in EC section contains a description based on open circuit inspection. A short circuit
inspection is also required for the circuit check in the Diagnostic Procedure. For details, refer toGI-24, "
How to Per-
form Efficient Diagnosis for an Electrical Incident", “Circuit Inspection”.
Repair or replace the malfunction parts.
If the malfunctioning part cannot be detected, performEC-699, "
TROUBLE DIAGNOSIS FOR INTERMITTENT INCI-
DENT".
STEP VIIOnce you have repaired the circuit or replaced a component, you need to run the engine in the same conditions and
circumstances which resulted in the customer's initial complaint.
Perform the “DTC Confirmation Procedure” and confirm the normal code (DTC P0000) is detected. If the incident is
still detected in the final check, perform STEP VI by using a different method from the previous one.
Before returning the vehicle to the customer, be sure to erase the unnecessary (already fixed) DTC in ECM. (Refer to
EC-666
.)
SEF907L
TROUBLE DIAGNOSIS
EC-673
[YD]
C
D
E
F
G
H
I
J
K
L
MA
EC
1.INSPECTION START
1. Check service records for any recent repairs that may indicate a related problem.
2. Check the current need for scheduled maintenance, especially for fuel filter and air cleaner filter. Refer to
MA-7, "
PERIODIC MAINTENANCE".
3. Open engine hood and check the following:
–Harness connectors for improper connections
–Vacuum hoses for splits, kinks, or improper connections
–Wiring for improper connections, pinches, or cuts
4. Start engine and warm it up to the normal operating tempera-
ture.
>> GO TO 2.
2.PREPARATION FOR CHECKING IDLE SPEED
With CONSULT-II
Connect CONSULT-II to the data link connector.
>> GO TO 3.
3.CHECK IDLE SPEED
With CONSULT-II
1. Select “CKPS·RPM (TDC)” in “DATA MONITOR” mode with CONSULT-II.
2. Read idle speed.
OK or NG
OK >>INSPECTION END
NG >> GO TO 4.
4.CHECK FOR INTAKE AIR LEAK
Listen for an intake air leak after the mass air flow sensor.
OK or NG
OK >> GO TO 5.
NG >> Repair or replace.
SEF142I
725±25 rpm
SEF817Y
EC-676
[YD]
TROUBLE DIAGNOSIS
Symptom Matrix Chart
EBS0037F
SYSTEM — Basic engine control systemSYMPTOM
Reference page
HARD/NO START/RESTART (EXCP. HA) ENGINE STALL HESITATION/SURGING/FLAT SPOT KNOCK/DETONATION
LACK OF POWER POOR ACCELERATION
HI IDLE
LOW IDLE
NO START (with first firing) NO START (without first firing)
HARD TO START WHEN ENGINE IS COLD HARD TO START WHEN ENGINE IS HOT AT I D L E
DURING DRIVING WHEN DECELERATING
Warranty symptom code AA AB AC AD AE AF
Fuelsupplypump 55555555 55 5 —
Fuelinjector 333 333 3334433EC-727
EDU(Electronicdriveunit) 444 444 4445544EC-754
Glow control system 1 1 1 1 1EC-796
Engine body 3 3 3 3 3 3 3 3 4 4 3EM-102
EGR system33EC-803
Air cleaner and duct33MA-31
Fuel pressure relief valveEC-665
ENGINE CONTROL
Suction control valve circuit 4 4 4 4 4 4 4 4 4 4 4EC-772
Fuelinjectorcircuit 111 111 1111111EC-727
EDUcircuit 222 222 2222222EC-754
Mass air flow sensor circuit 1 1 1EC-706
Engine coolant temperature circuit 1 1 1 1EC-711
Vehicle speed sensor circuit 1EC-744
Accelerator pedal position sensor circuit 1 1 1EC-715
Accelerator pedal released position
switch circuit111111EC-783
Common rail fuel pressure sensor
circuitEC-723
Crankshaft position sensor (TDC)
circuit1111111111EC-734