2009 NISSAN LATIO check engine light

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DTC P1805 BRAKE SWITCH
Description INFOID:0000000004537442
Brake switch signal is applied to the ECM through t he stop lamp switch when the brake pedal is depressed.
This signal is used mainly to decrease the engine speed when the vehicle is driving.
CONSULT-III Reference Val ue in Data Monitor Mode INFOID:0000000004537443
Specification data are reference values.
On Board Diagnosis Logic INFOID:0000000004537444
The MIL will not light up for this self-diagnosis.
FAIL-SAFE MODE When the malfunction is detected, the ECM enters in fail-safe mode.
DTC Confirmation Procedure INFOID:0000000004537445
1. Turn ignition switch ON.
2. Fully depress the brake pedal for at least 5 seconds.
3. Erase the DTC.
4. Check 1st trip DTC.
5. If 1st trip DTC is detected, go to EC-923, " Diagnosis Procedure " .
MONITOR ITEM CONDITION SPECIFICATION
BRAKE SW • Ignition switch: ON Brake pedal: Fully released OFF
Brake pedal: Slightly depressed ON DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P1805
1805 Brake switch A brake switch signal is not sent to ECM for
extremely long time while the vehicle is driv-
ing. • Harness or connectors
(Stop lamp switch circuit is open or shorted.)
• Stop lamp switch Engine operation condition in fail-fail safe mode
ECM controls the electric throttle control actuator by regulating the throttle opening to a small range. Therefore, acceleration will be poor.
Vehicle condition Driving condition Engine: Idling NormalAccelerating Poor acceleration

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DTC P2100, P2103 THROTTLE
CONTROL MOTOR RELAY
Component Description INFOID:0000000004537449
Power supply for the throttle control motor is provided to the ECM via throttle control motor relay. The throttle
control motor relay is ON/OFF controlled by the ECM. When the ignition switch is turned ON, the ECM sends
an ON signal to throttle control motor relay and batte ry voltage is provided to the ECM. When the ignition
switch is turned OFF, the ECM sends an OFF signal to throttle control motor relay and battery voltage is not
provided to the ECM.
CONSULT-III Reference Val ue in Data Monitor Mode INFOID:0000000004537450
Specification data are reference values.
On Board Diagnosis Logic INFOID:0000000004537451
These self-diagnoses have one trip detection logic.
FAIL-SAFE MODE When the malfunction is detected, ECM ent ers fail-safe mode and the MIL lights up.
DTC Confirmation Procedure INFOID:0000000004537452
NOTE:
If DTC Confirmation Procedure has been previously conduc ted, always turn ignition switch OFF and wait at
least 10 seconds before conducting the next test.
PROCEDURE FOR DTC P2100 1. Turn ignition switch ON and wait at least 2 seconds.
2. Start engine and let it idle for 5 seconds.
3. Check 1st trip DTC.
4. If DTC is detected, go to EC-927, " Diagnosis Procedure " .
PROCEDURE FOR DTC P2103 TESTING CONDITION:
Before performing the following procedure, confirm that battery voltage is more than 10V at idle.
1. Turn ignition switch ON and wait at least 1 second.
2. Check DTC.
3. If DTC is detected, go to EC-927, " Diagnosis Procedure " .
MONITOR ITEM CONDITION SPECIFICATION
THRTL RELAY • Ignition switch: ON ON DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P2100
2100 Throttle control motor
relay circuit open ECM detects a voltage of power source for
throttle control motor is excessively low. • Harness or connectors
(Throttle control motor relay circuit is
open)
• Throttle control motor relay
P2103
2103 Throttle control motor
relay circuit short ECM detects the throttle
control motor relay is
stuck ON. • Harness or connectors
(Throttle control motor relay circuit is
shorted)
• Throttle control motor relay Engine operating condition in fail-safe mode
ECM stops the electric throttle control actuator control, throttle valve is maintained at a fixed opening (approx. 5 degrees) b y the return
spring.

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DTC P2101 ELECTRIC THRO
TTLE CONTROL FUNCTION
Description INFOID:0000000004537455
NOTE:
If DTC P2101 is displayed with DTC P2100 or P2119, first perform the trouble diagnosis for DTC P2100
or P2119. Refer to EC-925 or
EC-940 .
Electric throttle control actuator consists of throttle control motor, throttle position sensor, etc.
The throttle control motor is operated by the ECM and it opens and closes the throttle valve.
The current opening angle of the throttle valve is detected by the throttle position sensor and it provides feed-
back to the ECM to control the throttle control motor to make the throttle valve opening angle properly in
response to driving condition.
On Board Diagnosis Logic INFOID:0000000004537456
This self-diagnosis has the on e trip detection logic.
FAIL-SAFE MODE When the malfunction is detec ted, the ECM enters fail-safe mode and the MIL lights up.
DTC Confirmation Procedure INFOID:0000000004537457
NOTE:
If DTC Confirmation Procedure has been previously conduc ted, always turn ignition switch OFF and wait at
least 10 seconds before conducting the next test.
TESTING CONDITION:
Before performing the follo wing procedure, confirm that battery vo ltage is more than 11V when engine
is running.
1. Turn ignition switch ON and wait at least 2 seconds.
2. Start engine and let it idle for 5 seconds.
3. Check DTC.
4. If DTC is detected, go to EC-931, " Diagnosis Procedure " .
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P2101
2101 Electric throttle control
performance Electric throttle control function does not oper-
ate properly. • Harness or connectors
(Throttle control motor circuit is open or
shorted)
• Electric throttle control actuator Engine operating condition in fail-safe mode
ECM stops the electric throttle control actuator control, throttle valve is maintained at a fixed opening (approx. 5 degrees) b y the return
spring.

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DTC P2118 THROTTLE CONTROL MOTOR
Component Description INFOID:0000000004537462
The throttle control motor is operated by the ECM and it opens and closes the throttle valve.
The current opening angle of the throttle valve is detected by the throttle position sensor and it provides feed-
back to the ECM to control the throttle control motor to make the throttle valve opening angle properly in
response to driving condition.
On Board Diagnosis Logic INFOID:0000000004537463
This self-diagnosis has the on e trip detection logic.
FAIL-SAFE MODE
When the malfunction is detected, ECM ent ers fail-safe mode and the MIL lights up.
DTC Confirmation Procedure INFOID:0000000004537464
NOTE:
If DTC Confirmation Procedure has been previously conduc ted, always turn ignition switch OFF and wait at
least 10 seconds before conducting the next test.
1. Turn ignition switch ON and wait at least 2 seconds.
2. Start engine and let it idle for 5 seconds.
3. Check DTC.
4. If DTC is detected, go to EC-937, " Diagnosis Procedure " .
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P2118
2118 Throttle control motor
circuit short ECM detects short in both circuits between
ECM and throttle control motor. • Harness or connectors
(Throttle control motor circuit is shorted.)
• Electric throttle control actuator
(Throttle control motor) Engine operating condition in fail-safe mode
ECM stops the electric throttle control actuator control, throttle valve is maintained at a fixed opening (approx. 5 degrees) b y the return
spring.

EC-954< SERVICE INFOMATION >
[MR TYPE 1]
DTC P2135 TP SENSOR
DTC P2135 TP SENSOR
Component Description INFOID:0000000004537489
Electric throttle control actuator consists of throttle control motor,
throttle position sensor, etc. The throttle position sensor responds to
the throttle valve movement.
The throttle position sensor has two sensors. These sensors are a
kind of potentiometers which transform the throttle valve position into
output voltage, and emit the voltage signal to the ECM. In addition,
these sensors detect the opening and closing speed of the throttle
valve and feed the voltage signals to the ECM. The ECM judges the
current opening angle of the throttle valve from these signals and the
ECM controls the throttle control motor to make the throttle valve
opening angle properly in response to driving condition.
CONSULT-III Reference Value in Data Monitor Mode INFOID:0000000004537490
Specification data are reference values.
*: Throttle position sensor 2 signal is converted by ECM internally. Thus, it differs from ECM terminal voltage signal.
On Board Diagn osis Logic INFOID:0000000004537491
This self-diagnosis has the one trip detection logic.
NOTE:
If DTC P2135 is displayed with DTC P0643, firs t perform the trouble diagnosis for DTC P0643.
Refer to EC-874 .
FAIL-SAFE MODE
When the malfunction is detected, the ECM enters fail-safe mode and the MIL lights up.
DTC Confirmation Procedure INFOID:0000000004537492
NOTE:
If DTC Confirmation Procedure has been previously conduc ted, always turn ignition switch OFF and wait at
least 10 seconds before conducting the next test.
TESTING CONDITION:
Before performing the following procedure, confirm that battery voltage is more than 8V at idle.
1. Start engine and let it idle for 1 second.
2. Check DTC.
3. If DTC is detected, go to EC-956, " Diagnosis Procedure " . PBIB0145E
MONITOR ITEM CONDITION SPECIFICATION
TP SEN 1-B1
TP SEN 2-B1* • Ignition switch: ON
(Engine stopped) Accelerator pedal: Fully released More than 0.36V
• Shift lever: D (A/T, CVT), 1st (M/T) Accelerator pedal: Fully depressed Less than 4.75V DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P2135
2135 Throttle position sensor
circuit range/performance Rationally incorrect voltage is sent to ECM
compared with the signals from TP sensor 1
and TP sensor 2. • Harness or connector
(TP sensor 1 and 2 circuit is open or short-
ed.)
• Electric throttle control actuator
(TP sensor 1 and 2) Engine operation condition in fail-safe mode
The ECM controls the electric throttle control actuator in regulating the throttle opening in order for the idle position to be within +10
degrees.
The ECM regulates the opening speed of the throttle valve to be slower than the normal condition.
So, the acceleration will be poor.

PRECAUTIONS
EC-1023
< SERVICE INFOMATION >
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Keep engine control system parts and harness dry.
• Before replacing ECM, perform “ECM Terminals and Refer-
ence Value” inspection and m ake sure ECM functions prop-
erly. Refer to EC-1109, " ECM Terminal and Reference Value " .
• Handle mass air flow sensor carefully to avoid damage.
• Do not disassemble mass air flow sensor.
• Do not clean mass air flow senso r with any type of detergent.
• Do not disassemble electric th rottle control actuator.
• Even a slight leak in the air intake system can cause serious
incidents.
• Do not shock or jar the camsh aft position sensor (PHASE),
crankshaft position sensor (POS).
• After performing each TROUBL E DIAGNOSIS, perform DTC
Confirmation Procedure or Overall Function Check.
The DTC should not be displ ayed in the DTC Confirmation
Procedure if the repair is completed. The Overall Function
Check should be a good result if the repair is completed.
• When measuring ECM signals with a circuit tester, never allow
the two tester probes to contact.
Accidental contact of probes will cause a short circuit and
damage the ECM power transistor.
• Do not use ECM ground termina ls when measuring input/out-
put voltage. Doing so may result in damage to the ECM's tran-
sistor. Use a ground other than ECM terminals, such as the
ground. MEF040D
SEF217U
SEF348N

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ON BOARD DIAGNOSTIC (OBD) SYSTEM
Introduction INFOID:0000000004499924
The ECM has an on board diagnostic system, which detects malfunctions related to engine sensors or actua-
tors. The ECM also records various emis sion-related diagnostic information including:
The above information can be checked using procedures listed in the table below. ×: Applicable —: Not applicable
*: When DTC and 1st trip DTC simultaneously appear on the display, they cannot be clearly distinguished from each other.
The malfunction indicator lamp (MIL) on the instrument panel lights up when the same malfunction is detected
in two consecutive trips (Two trip detection logic), or when the ECM enters fail-safe mode.
(Refer to EC-1094, " Fail-Safe Chart " .)
Two Trip Detection Logic INFOID:0000000004499925
When a malfunction is detected for the first time, 1st tr ip DTC and 1st trip Freeze Frame data are stored in the
ECM memory. The MIL will not light up at this stage. <1st trip>
If the same malfunction is detected again during the next drive, the DTC and Freeze Frame data are stored in
the ECM memory, and the MIL lights up. The MIL lights up at the same time when the DTC is stored. <2nd
trip> The “trip” in the “Two Trip Detection Logic” m eans a driving mode in which self-diagnosis is performed
during vehicle operation. Specific on board diagnostic item s will cause the ECM to light up or blink the MIL,
and store DTC and Freeze Frame data, even in the 1st trip, as shown below.
×: Applicable —: Not applicable
When there is an open circuit on MIL circuit, the ECM c annot warn the driver by MIL lighting up when there is
malfunction on engine control system. Emission-related diagnostic information Diagnostic service
Diagnostic Tr ouble Code (DTC) Service $03 of SAE J1979
Freeze Frame data Service $02 of SAE J1979
System Readiness Test (SRT) code Service $01 of SAE J1979
1st Trip Diagnostic Trou ble Code (1st Trip DTC) Service $07 of SAE J1979
1st Trip Freeze Frame data
Test values and Test limi ts Service $06 of SAE J1979
Calibration ID Servic e $09 of SAE J1979
DTC 1st trip DTC Freeze Frame
data 1st trip Freeze
Frame data SRT code SRT status Test value
CONSULT-III × × × × × × —
GST × × × —× × ×
ECM × ×* — — — ×— Items
MIL DTC 1st trip DTC
1st trip 2nd trip 1st trip
displaying 2nd trip
displaying 1st trip
displaying 2nd trip
display-
ing
Blinking Lighting
up Blinking
Lighting
up
Misfire (Possible three way catalyst
damage) — DTC: P0300 - P0304 is
being detected ×
— — — — — ×—
Misfire (Possible three way catalyst
damage) — DTC: P0300 - P0304 is
being detected — —
×— — ×— —
One trip detection diagnoses
(Refer to EC-1052, " Emission-relat-
ed Diagnostic Information " .)
—
×— — ×— — —
Except above — — — ×— × × —

ON BOARD DIAGNOSTIC (OBD) SYSTEM
EC-1069
< SERVICE INFOMATION >
[MR TYPE 2] C
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4. Touch "ERASE". (The DTC in the ECM will be erased.)
With GST
NOTE:
If the ignition switch stays ON after repair work, be sure to turn ignition switch OFF once. Wait at least 10 sec-
onds and then turn it ON (engine stopped) again.
1. Select Service $04 with GST.
No Tools
NOTE:
If the ignition switch stays ON after repair work, be sure to turn ignition switch OFF once. Wait at least 10 sec-
onds and then turn it ON (engine stopped) again.
1. Erase DTC in ECM. Refer to How to Erase Diagnostic Test Mode II (Self-diagnostic Results).
• If the battery is disconnected, the emission-relate d diagnostic information will be lost within 24
hours.
• The following data are cleared when the ECM memory is erased.
- Diagnostic trouble codes
- 1st trip diagnostic trouble codes
- Freeze frame data
- 1st trip freeze frame data
- System readiness test (SRT) codes
- Test values
Malfunction Indicator Lamp (MIL) INFOID:0000000004499927
DESCRIPTION The MIL is located on the instrument panel.
1. The MIL will light up when the ignition switch is turned ON with- out the engine running. This is a bulb check.
If the MIL does not light up, refer to DI-20 or see
EC-1532 .
2. When the engine is start ed, the MIL should go off.
If the MIL remains on, the on board diagnostic system has
detected an engine system malfunction.
ON BOARD DIAGNOSTIC SYSTEM FUNCTION The on board diagnostic system has the following three functions. SEF217U