
EC-28
< SERVICE INFORMATION >
AUTOMATIC SPEED CONTROL DEVICE (ASCD)
AUTOMATIC SPEED CONTROL DEVICE (ASCD)
System DescriptionINFOID:0000000001702560
INPUT/OUTPUT SIGNAL CHART
*: This signal is sent to the ECM through CAN communication line.
BASIC ASCD SYSTEM
Refer to Owner's Manual for ASCD operating instructions.
Automatic Speed Control Device (ASCD) allows a driver to keep vehicle at predetermined constant speed
without depressing accelerator pedal. Driver can set vehicle speed in advance between approximately 40 km/
h (25 MPH) and 144 km/h (89 MPH).
ECM controls throttle angle of electric throttle control actuator to regulate engine speed.
Operation status of ASCD is indicated by CRUISE indicator and SET indicator in combination meter. If any
malfunction occurs in ASCD system, it automatically deactivates control.
NOTE:
Always drive vehicle in safe manner according to traffic conditions and obey all traffic laws.
SET OPERATION
Press MAIN switch. (The CRUISE indicator in combination meter illuminates.)
When vehicle speed reaches a desired speed between approximately 40 km/h (25 MPH) and 144 km/h (89
MPH), press SET/COAST switch. (Then SET indicator in combination meter illuminates.)
ACCELERATE OPERATION
If the RESUME/ACCELERATE switch is depressed during cruise control driving, increase the vehicle speed
until the switch is released or vehicle speed reaches maximum speed controlled by the system.
And then ASCD will keep the new set speed.
CANCEL OPERATION
When any of following conditions exist, cruise operation will be canceled.
• CANCEL switch is pressed
• More than two switches at ASCD steering switch are pressed at the same time (Set speed will be cleared)
• Brake pedal is depressed
• Clutch pedal is depressed or gear position is changed to the neutral position (M/T models)
• Selector lever is changed to N, P, R position (A/T and CVT models)
• Vehicle speed decreased to 13 km/h (8 MPH) lower than the set speed
When the ECM detects any of the following conditions, the ECM will cancel the cruise operation and inform
the driver by blinking indicator lamp.
• Engine coolant temperature is slightly higher than the normal operating temperature, CRUISE lamp may
blink slowly.
When the engine coolant temperature decreases to the normal operating temperature, CRUISE lamp will
stop blinking and the cruise operation will be able to work by pressing SET/COAST switch or RESUME/
ACCELERATE switch.
• Malfunction for some self-diagnoses regarding ASCD control: SET lamp will blink quickly.
If MAIN switch is turned to OFF during ASCD is activated, all of ASCD operations will be canceled and vehicle
speed memory will be erased.
COAST OPERATION
When the SET/COAST switch is depressed during cruise control driving, decrease vehicle set speed until the
switch is released. And then ASCD will keep the new set speed.
Sensor Input signal to ECM ECM function Actuator
ASCD brake switch Brake pedal operation
ASCD vehicle speed controlElectric throttle control
actuator Stop lamp switch Brake pedal operation
ASCD clutch switch (M/T models) Clutch pedal operation
ASCD steering switch ASCD steering switch operation
Park/neutral position (PNP) switch Gear position
Combination meter Vehicle speed*
TCM (A/T and CVT models) Powertrain revolution*

EC-76
< SERVICE INFORMATION >
BASIC SERVICE PROCEDURE
Accelerator Pedal Released Position Learning
INFOID:0000000001702582
DESCRIPTION
Accelerator Pedal Released Position Learning is an operation to learn the fully released position of the accel-
erator pedal by monitoring the accelerator pedal position sensor output signal. It must be performed each time
harness connector of accelerator pedal position sensor or ECM is disconnected.
OPERATION PROCEDURE
1. Make sure that accelerator pedal is fully released.
2. Turn ignition switch ON and wait at least 2 seconds.
3. Turn ignition switch OFF and wait at least 10 seconds.
4. Turn ignition switch ON and wait at least 2 seconds.
5. Turn ignition switch OFF and wait at least 10 seconds.
Throttle Valve Closed Position LearningINFOID:0000000001702583
DESCRIPTION
Throttle Valve Closed Position Learning is an operation to learn the fully closed position of the throttle valve by
monitoring the throttle position sensor output signal. It must be performed each time harness connector of
electric throttle control actuator or ECM is disconnected.
OPERATION PROCEDURE
1. Make sure that accelerator pedal is fully released.
2. Turn ignition switch ON.
3. Turn ignition switch OFF and wait at least 10 seconds.
Make sure that throttle valve moves during above 10 seconds by confirming the operating sound.
Idle Air Volume LearningINFOID:0000000001702584
DESCRIPTION
Idle Air Volume Learning is an operation to learn the idle air volume that keeps each engine within the specific
range. It must be performed under any of the following conditions:
• Each time electric throttle control actuator or ECM is replaced.
• Idle speed or ignition timing is out of specification.
PREPARATION
Before performing Idle Air Volume Learning, make sure that all of the following conditions are satisfied.
Learning will be cancelled if any of the following conditions are missed for even a moment.
• Battery voltage: More than 12.9V (At idle)
• Engine coolant temperature: 70 - 95°C (158 - 203°F)
• Park/neutral position (PNP) switch: ON
• Electric load switch: OFF
[Air conditioner, headlamp, rear window defogger]
On vehicles equipped with daytime light systems, if the parking brake is applied before the engine is
started the headlamp will not be illuminated.
• Steering wheel: Neutral (Straight-ahead position)
• Vehicle speed: Stopped
• Transmission: Warmed-up
- Models with CONSULT-II (A/T and CVT models)
• Drive vehicle until “FLUID TEMP SE” in “DATA MONITOR” mode of “A/T” or “CVT” system indicates less
than 0.9V.
- Models without CONSULT-II (A/T and CVT models) and M/T models
• Drive vehicle for 10 minutes.
OPERATION PROCEDURE
With CONSULT-II
1. Perform EC-76, "Accelerator Pedal Released Position Learning".
2. Perform EC-76, "
Throttle Valve Closed Position Learning".

TROUBLE DIAGNOSIS
EC-89
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SYMPTOM
Reference
page
HARD/NO START/RESTART (EXCP. HA)
ENGINE STALL
HESITATION/SURGING/FLAT SPOT
SPARK KNOCK/DETONATION
LACK OF POWER/POOR ACCELERATION
HIGH IDLE/LOW IDLE
ROUGH IDLE/HUNTING
IDLING VIBRATION
SLOW/NO RETURN TO IDLE
OVERHEATS/WATER TEMPERATURE HIGH
EXCESSIVE FUEL CONSUMPTION
EXCESSIVE OIL CONSUMPTION
BATTERY DEAD (UNDER CHARGE)
Warranty symptom code AA AB AC AD AE AF AG AH AJ AK AL AM HA
Fuel Fuel pump circuit 11232 22 3 2EC-526
Fuel pressure regulator system 334444444 4EC-78
Fuel injector circuit 11232 22 2EC-521
Evaporative emission system 334444444 4EC-31
Air Positive crankcase ventilation sys-
tem
334444444 41EC-43
Incorrect idle speed adjustment 1 1 1 1 1EC-69
Electric throttle control actuator 112332222 2 2EC-461,
EC-472
IgnitionIncorrect ignition timing adjustment33111 11 1EC-69
Ignition circuit 11222 22 2EC-531
Main power supply and ground circuit 22333 33 23EC-137
Mass air flow sensor circuit
1
122
222 2EC-167,
EC-175
Engine coolant temperature sensor circuit
333EC-187,
EC-198
Air fuel ratio (A/F) sensor 1 circuitEC-206
,
EC-213
,
EC-219
,
EC-225
,
EC-500
Throttle position sensor circuit
22EC-192
,
EC-278
,
EC-426
,
EC-428
,
EC-487
Accelerator pedal position sensor circuit 3 2 1EC-400
,
EC-474
,
EC-480
,
EC-493
Knock sensor circuit 2 3EC-291
Crankshaft position sensor (POS) circuit 2 2EC-295
Camshaft position sensor (PHASE) circuit 3 2EC-302
Vehicle speed signal circuit 2 3 3 3EC-391
ECM 22333333333EC-397

EC-90
< SERVICE INFORMATION >
TROUBLE DIAGNOSIS
1 - 6: The numbers refer to the order of inspection.
(continued on next page)
SYSTEM — ENGINE MECHANICAL & OTHER
Intake valve timing control solenoid valve cir-
cuit32 13223 3EC-162
Park/neutral position (PNP) switch circuit 3 3 3 3 3EC-405
Refrigerant pressure sensor circuit 2 3 3 4EC-541
Electrical load signal circuit 3EC-519
Air conditioner circuit 223333333 3 2MTC-22
ABS actuator and electric unit (control unit) 4BRC-8
SYMPTOM
Reference
page
HARD/NO START/RESTART (EXCP. HA)
ENGINE STALL
HESITATION/SURGING/FLAT SPOT
SPARK KNOCK/DETONATION
LACK OF POWER/POOR ACCELERATION
HIGH IDLE/LOW IDLE
ROUGH IDLE/HUNTING
IDLING VIBRATION
SLOW/NO RETURN TO IDLE
OVERHEATS/WATER TEMPERATURE HIGH
EXCESSIVE FUEL CONSUMPTION
EXCESSIVE OIL CONSUMPTION
BATTERY DEAD (UNDER CHARGE)
Warranty symptom code AA AB AC AD AE AF AG AH AJ AK AL AM HA
SYMPTOM
Reference
page
HARD/NO START/RESTART (EXCP. HA)
ENGINE STALL
HESITATION/SURGING/FLAT SPOT
SPARK KNOCK/DETONATION
LACK OF POWER/POOR ACCELERATION
HIGH IDLE/LOW IDLE
ROUGH IDLE/HUNTING
IDLING VIBRATION
SLOW/NO RETURN TO IDLE
OVERHEATS/WATER TEMPERATURE HIGH
EXCESSIVE FUEL CONSUMPTION
EXCESSIVE OIL CONSUMPTION
BATTERY DEAD (UNDER CHARGE)
Warranty symptom code AA AB AC AD AE AF AG AH AJ AK AL AM HA
Fuel Fuel tank
5
5FL-9
Fuel piping 5 5 5 5 5 5EM-33
Va p o r l o c k—
Valve deposit
5 555 55 5—
Poor fuel (Heavy weight gasoline,
Low octane)—

TROUBLE DIAGNOSIS
EC-91
< SERVICE INFORMATION >
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Air Air duct
55555 5EM-16
Air cleanerEM-16
Air leakage from air duct
(Mass air flow sensor — electric
throttle control actuator)
5555EM-16
Electric throttle control actuatorEM-18
Air leakage from intake manifold/
Collector/GasketEM-18
Cranking Battery
111111
11SC-4
Generator circuitSC-20
Starter circuit 3SC-8
Signal plate 6EM-76
Park/neutral position (PNP)
switch4MT-12, AT-
86 or
CVT-65
Engine Cylinder head
55555 55 5EM-62
Cylinder head gasket 4 3
Cylinder block
66666 66 64
EM-76
Piston
Piston ring
Connecting rod
Bearing
Crankshaft
Va l v e
mecha-
nismTiming chain
55555 55 5EM-37
CamshaftEM-47
Intake valve timing controlEM-37
Intake valve
3EM-62
Exhaust valve
Exhaust Exhaust manifold/Tube/Muffler/
Gasket
55555 55 5EM-21
, EX-
4Three way catalyst
Lubrica-
tionOil pan/Oil strainer/Oil pump/Oil
filter/Oil gallery
55555 55 5EM-24
, LU-
9
Oil level (Low)/Filthy oilLU-6
SYMPTOM
Reference
page
HARD/NO START/RESTART (EXCP. HA)
ENGINE STALL
HESITATION/SURGING/FLAT SPOT
SPARK KNOCK/DETONATION
LACK OF POWER/POOR ACCELERATION
HIGH IDLE/LOW IDLE
ROUGH IDLE/HUNTING
IDLING VIBRATION
SLOW/NO RETURN TO IDLE
OVERHEATS/WATER TEMPERATURE HIGH
EXCESSIVE FUEL CONSUMPTION
EXCESSIVE OIL CONSUMPTION
BATTERY DEAD (UNDER CHARGE)
Warranty symptom code AA AB AC AD AE AF AG AH AJ AK AL AM HA
![NISSAN LATIO 2008 Service Repair Manual EC-104
< SERVICE INFORMATION >
TROUBLE DIAGNOSIS
15 Y Throttle control motor relay[Ignition switch: OFF]BATTERY VOLTAGE
(11 - 14V)
[Ignition switch: ON]0 - 1.0V
17
18
21
22R
LG
G
SBIgnition signal No NISSAN LATIO 2008 Service Repair Manual EC-104
< SERVICE INFORMATION >
TROUBLE DIAGNOSIS
15 Y Throttle control motor relay[Ignition switch: OFF]BATTERY VOLTAGE
(11 - 14V)
[Ignition switch: ON]0 - 1.0V
17
18
21
22R
LG
G
SBIgnition signal No](/manual-img/5/57360/w960_57360-1177.png)
EC-104
< SERVICE INFORMATION >
TROUBLE DIAGNOSIS
15 Y Throttle control motor relay[Ignition switch: OFF]BATTERY VOLTAGE
(11 - 14V)
[Ignition switch: ON]0 - 1.0V
17
18
21
22R
LG
G
SBIgnition signal No. 1
Ignition signal No. 2
Ignition signal No. 4
Ignition signal No. 3[Engine is running]
•Warm-up condition
• Idle speed
NOTE:
The pulse cycle changes depending on rpm
at idle.0 - 0.3V
[Engine is running]
• Warm-up condition
• Engine speed: 2,500 rpm.0.2 - 0.5V
23 GR Fuel pump relay[Ignition switch: ON]
• For 1 second after turning ignition switch
ON
[Engine is running]0 - 1.0V
[Ignition switch: ON]
• More than 1 second after turning ignition
switch ONBATTERY VOLTAGE
(11 - 14V)
25
29
30
31V
Y
O
LFuel injector No. 4
Fuel injector No. 3
Fuel injector No. 2
Fuel injector No. 1[Engine is running]
•Warm-up condition
• Idle speed
NOTE:
The pulse cycle changes depending on rpm
at idle.BATTERY VOLTAGE
(11 - 14V)
[Engine is running]
•Warm-up condition
• Engine speed: 2,000 rpmBATTERY VOLTAGE
(11 - 14V)
28 WEVAP canister vent control
valve[Ignition switch: ON]BATTERY VOLTAGE
(11 - 14V)
32 PECM relay
(Self shut-off)[Engine is running]
[Ignition switch: OFF]
• For a few seconds after turning ignition
switch OFF0 - 1.0V
[Ignition switch: OFF]
• More than a few seconds after turning igni-
tion switch OFFBATTERY VOLTAGE
(11 - 14V) TERMI-
NAL
NO.WIRE
COLORITEM CONDITION DATA (DC Voltage)
PBIA9265J
PBIA9266J
PBIB0529E
PBIA4943J

TROUBLE DIAGNOSIS
EC-117
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NOTE:
Any monitored item that does not match the vehicle being diagnosed is deleted from the display automatically.
ACTIVE TEST MODE
Test Item
Monitored item [Unit]ECM
input
signalsMain
signalsDescription Remarks
ENG SPEED [rpm]×ו Indicates the engine speed computed
from the signal of the crankshaft position
sensor (POS) and camshaft position
sensor (PHASE).
MAS A/F SE-B1 [V]×ו The signal voltage of the mass air flow
sensor specification is displayed.• When engine is running specification
range is indicated.
B/FUEL SCHDL
[msec]ו “Base fuel schedule” indicates the fuel in-
jection 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 [%]ו 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.
TEST ITEM CONDITION JUDGEMENT CHECK ITEM (REMEDY)
FUEL INJEC-
TION• Engine: Return to the original
trouble condition
• Change the amount of fuel injec-
tion using CONSULT-II.If trouble symptom disappears, see
CHECK ITEM.• Harness and connectors
• Fuel injector
• Air fuel ratio (A/F) sensor 1
IGNITION TIM-
ING• Engine: Return to the original
trouble condition
• Timing light: Set
• Retard the ignition timing using
CONSULT-II.If trouble symptom disappears, see
CHECK ITEM.• Perform Idle Air Volume Learning.
POWER BAL-
ANCE• Engine: After warming up, idle the
engine.
• A/C switch OFF
• Shift lever: P or N (A/T, CVT),
Neutral (M/T)
• Cut off each fuel injector signal
one at a time using CONSULT-II.Engine runs rough or dies.• Harness and connectors
• Compression
• Fuel injector
• Power transistor
•Spark plug
• Ignition coil
COOLING FAN*• Ignition switch: ON
• Turn the cooling fan “LOW”, “HI”
and “OFF” with CONSULT-II.Cooling fan moves and stops.• Harness and connectors
• Cooling fan relay
• Cooling fan motor
ENG COOLANT
TEMP• Engine: Return to the original
trouble condition
• Change the engine coolant tem-
perature using CONSULT-II.If trouble symptom disappears, see
CHECK ITEM.• Harness and connectors
• Engine coolant temperature sen-
sor
• Fuel injector
FUEL PUMP RE-
LAY• Ignition switch: ON
(Engine stopped)
• Turn the fuel pump relay ON and
OFF using CONSULT-II and lis-
ten to operating sound.Fuel pump relay makes the operat-
ing sound.• Harness and connectors
• Fuel pump relay
PURG VOL
CONT/V• Engine: After warming up, run en-
gine at 1,500 rpm.
• Change the EVAP canister purge
volume control solenoid valve
opening percent using CON-
SULT-II.Engine speed changes according to
the opening percent.• Harness and connectors
• EVAP canister purge volume con-
trol solenoid valve

TROUBLE DIAGNOSIS
EC-121
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3. Turn ignition switch ON.
4. Enter the program according to instruction on the screen or in
the operation manual.
(*: Regarding GST screens in this section, sample screens are
shown.)
5. Perform each diagnostic service according to each service pro-
cedure.
For further information, see the GST Operation Manual of
the tool maker.
CONSULT-II Reference Value in Data Monitor ModeINFOID:0000000001702597
Remarks:
● Specification data are reference values.
● Specification data are output/input values which are detected or supplied by the ECM at the connector.
* Specification data may not be directly related to their components signals/values/operations.
i.e. Adjust ignition timing with a timing light before monitoring IGN TIMING, because the monitor may show the specification data in spite of the
ignition timing not being adjusted to the specification data. This IGN TIMING monitors the data calculated by the ECM according to the signals
input from the camshaft position sensor and other ignition timing related sensors.
SEF398S
SEF416S
MONITOR ITEM CONDITION SPECIFICATION
ENG SPEED • Run engine and compare CONSULT-II value with the tachometer indication.Almost the same speed as the
tachometer indication.
MAS A/F SE-B1 See EC-127
.
B/FUEL SCHDL See EC-127
.
A/F ALPHA-B1 See EC-127
.
COOLAN TEMP/S • Engine: After warming up More than 70°C (158°F)
A/F SEN1 (B1) • Engine: After warming up Maintaining engine speed at 2,000 rpm Fluctuates around 2.2V
HO2S2 (B1)• Revving engine from idle to 3,000 rpm quickly after the following conditions
are met
- Engine: After warming up
- Keeping the engine speed between 3,500 and 4,000 rpm for 1 minute and
at idle for 1 minute under no load 0 - 0.3V ←→ Approx. 0.6 -
1.0V
HO2S2 MNTR (B1)LEAN ←→ RICH
VHCL SPEED SE• Turn drive wheels and compare CONSULT-II value with the speedometer
indication.Almost the same speed as the
speedometer indication.
BATTERY VOLT • Ignition switch: ON (Engine stopped) 11 - 14V
ACCEL SEN 1
ACCEL SEN 2*• Ignition switch: ON
(Engine stopped)Accelerator pedal: Fully released 0.6 - 0.9V
Accelerator pedal: Fully depressed 4.0 - 4.8V
EVAP SYS PRES • Ignition switch: ON Approx. 1.8 - 4.8V