2008 INFINITI QX56 stop start

EC-366
< COMPONENT DIAGNOSIS >[VK56DE]
P2118 THROTTLE CONTROL MOTOR
P2118 THROTTLE CONTROL MOTOR
Component DescriptionINFOID:0000000001528866
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 mo tor to make the throttle valve opening angle properly in
response to driving condition.
On Board Diagn osis LogicINFOID:0000000001528867
This self-diagnosis has the one trip detection logic.
FA I L - S A F E M O D E
When the malfunction is detected, the ECM enters fail-safe mode and the MIL lights up.
DTC Confirmation ProcedureINFOID:0000000001528868
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.
WITH CONSULT-III
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-366, "
Diagnosis Procedure".
WITH GST
Follow the procedure “WITH CONSULT-III” above.
Diagnosis ProcedureINFOID:0000000001528870
1.CHECK GROUND CONNECTIONS
1. Turn ignition switch OFF.
2. Loosen and retighten three ground screws on the body. Refer to EC-86, "
Ground Inspection".
OK or NG
OK >> GO TO 2.
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.
BBIA0354E
Revision: March 2010 2008 QX56

EC-368
< COMPONENT DIAGNOSIS >[VK56DE]
P2119 ELECTRIC THROTTLE CONTROL ACTUATOR
P2119 ELECTRIC THROTTLE CONTROL ACTUATOR
Component DescriptionINFOID:0000000001528873
Electric throttle control actuator consists of th
rottle control motor, throttle position sensor, etc.
The throttle control motor is operated by the ECM and it opens and closes the throttle valve.
The throttle position sensor detects the throttle va lve position, and the opening and closing speed of the throt-
tle valve and feeds 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 thrott le control motor to make the throttle valve opening
angle properly in response to driving condition.
On Board Diagn osis LogicINFOID:0000000001528874
This self-diagnosis has one trip detection logic.
FA I L - S A F E M O D E
When the malfunction is detected, ECM enters fail-safe mode and the MIL lights up.
DTC Confirmation ProcedureINFOID:0000000001528875
NOTE:
•Perform PROCEDURE FOR MALFUNCTION A AND B first. If the DTC cannot be confirmed, perform
PROCEDURE FOR MALFUNCTION C.
• If DTC Confirmation Procedure has been previously conducted, always turn ignition switch OFF and wait at least 10 seconds before conducting the next test.
PROCEDURE FOR MALFUNCTION A AND B
With CONSULT-III
1. Turn ignition switch ON and wait at least 1 second.
2. Shift selector lever to D position and wait at least 3 seconds.
3. Shift selector lever to P or N position.
4. Turn ignition switch OFF and wait at least 10 seconds.
5. Turn ignition switch ON and wait at least 1 second.
6. Shift selector lever to D position and wait at least 3 seconds.
7. Shift selector lever to P or N position.
8. Turn ignition switch OFF, wait at least 10 seconds and then turn ON.
9. Check DTC.
10. If DTC is detected, go to EC-369, "
Diagnosis Procedure".
With GST
Follow the procedure “With CONSULT-III” above.
DTC No. Trouble diagnosis name DTC detecting conditionPossible cause
P2119
2119 Electric throttle control
actuator A)
Electric throttle control
actuator does not func-
tion properly due to the return spring malfunc-
tion. • Electric throttle control actuator
B) Throttle valve opening angle in fail-safe mode is
not in specified range.
C) ECM detect the throttle valve is stuck open.
Detected items Engine operating condition in fail-safe mode
Malfunction A The ECM controls the electric throttle actuator by regulating the throttle opening around the idle position.
The engine speed will not rise more than 2,000 rpm.
Malfunction B ECM controls the electric throttle control actuator by regulating the throttle opening to 20 degrees or less.
Malfunction C While the vehicle is driving, it slows down gradually by fuel cut. After the vehicle stops, the engine stalls.
The engine can restart in N or P position, and engine speed will not exceed 1,000 rpm or more.
Revision: March 2010
2008 QX56

EC-386
< COMPONENT DIAGNOSIS >[VK56DE]
P2A00, P2A03 A/F SENSOR 1
8. Keep engine speed between 2,500 and 3,000 rpm for 20 minutes.
9. Check 1st trip DTC.
10. If 1st trip DTC is detected, go to
EC-386, "
Diagnosis Procedure".
WITH GST
1. Start engine and warm it up to normal operating temperature.
2. Turn ignition switch OFF and wait at least 10 seconds.
3. Disconnect mass air flow sensor harness connector.
4. Start engine and let it idle for at least 5 seconds.
5. Stop engine and reconnect mass air flow sensor harness con-
nector.
6. Select Service $03 with GST and make sure that DTC P0102 is detected.
7. Select Service $04 with GST and erase the DTC P0102.
8. Start engine and keep the engine speed between 3,500 and 4,000 rpm for 1 minute under no load.
9. Let engine idle for 1 minute.
10. Keep engine speed between 2,500 and 3,000 rpm for 20 min- utes.
11. Select Service $07 with GST. If 1st trip DTC is detected, go to EC-386, "
Diagnosis Procedure".
Diagnosis ProcedureINFOID:0000000001365861
1.CHECK GROUND CONNECTIONS
1. Turn ignition switch OFF.
2. Loosen and retighten two ground screws on the body. Refer to EC-86, "
Ground Inspection".
OK or NG
OK >> GO TO 2.
NG >> Repair or replace ground connections.
2.RETIGHTEN A/F SENSOR 1
1. Loosen and retighten the A/F sensor 1.
BBIA0368E
BBIA0354E
Tightening torque: 50 N-m (5.1 kg-m, 37 ft-lb)
BBIA0375E
Revision: March 2010 2008 QX56

P2A00, P2A03 A/F SENSOR 1EC-387
< COMPONENT DIAGNOSIS > [VK56DE]
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>> GO TO 3.
3.CHECK FOR INTAKE AIR LEAK
1. Start engine and run it at idle.
2. Listen for an intake air leak after the mass air flow sensor.
OK or NG
OK >> GO TO 4.
NG >> Repair or replace.
4.CLEAR THE SELF-LEARNING DATA
With CONSULT-IIl
1. Start engine and warm it up to normal operating temperature.
2. Select “SELF-LEARNING CONT” in “W ORK SUPPORT” mode with CONSULT-IIl.
3. Clear the self-learning control coefficient by touching “CLEAR”.
4. Run engine for at least 10 minutes at idle speed. Is the 1st trip DTC P0171, P0172, P0174 or P0175 detected?
Is it difficult to start engine?
Without CONSULT-IIl
1. Start engine and warm it up to normal operating temperature.
2. Turn ignition switch OFF.
3. Disconnect mass air flow sensor harness connector.
4. Restart engine and let it idle for at least 5 seconds.
5. Stop engine and reconnect mass air flow sensor harness con-
nector.
6. Make sure DTC P0102 is displayed.
7. Erase the DTC memory. Refer to EC-462, "
DTC Index".
8. Make sure DTC P0000 is displayed.
9. Run engine for at least 10 minutes at idle speed. Is the 1st trip DTC P0171, P0172, P0174 or P0175 detected?
Is it difficult to start engine?
Ye s o r N o
Yes >> Perform trouble diagnos is for DTC P0171, P0174 or
P0172, P0175. Refer to EC-176
or EC-182.
No >> GO TO 5.
5.CHECK HARNESS CONNECTOR
1. Turn ignition switch OFF.
2. Disconnect A/F sensor 1 harness connector.
3. Check harness connector for water.
OK or NG
OK >> GO TO 6.
NG >> Repair or replace harness connector.
6.CHECK A/F SENSOR 1 POWER SUPPLY CIRCUIT
BBIA0368E
Water should not exit.
BBIA0376E
Revision: March 2010 2008 QX56

P2A00, P2A03 A/F SENSOR 1EC-389
< COMPONENT DIAGNOSIS > [VK56DE]
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10.CHECK INTERMITTENT INCIDENT
Perform GI-35, "
How to Check Terminal" and GI-38, "Intermittent Incident".
OK or NG
OK >> GO TO 11.
NG >> Repair or replace.
11 .REPLACE AIR FUEL RATIO (A/F) SENSOR 1
Replace malfunctioning air f uel ratio (A/F) sensor 1.
CAUTION:
• Discard any A/F sensor which has been dropped from a height of more than 0.5 m (19.7 in) onto a
hard surface such as a concrete floor; use a new one.
• Before installing new A/F senso r, clean exhaust system threads using Oxygen Sensor Thread
Cleaner tool J-43897-18 or J-43897-12 and approved anti-seize lubricant.
>> GO TO 12.
12.CONFIRM A/F ADJUSTMENT DATA
1. Turn ignition switch OFF and then ON.
2. Select “A/F ADJ-B1” and “” in “DATA MONITOR” mode with CONSULT-lll.
3. Make sure that “0.000” is displayed on CONSULT-lll screen.
OK or NG
OK >> INSPECTION END
NG >> GO TO 13.
13.CLEAR THE SELF-LEARNING DATA
With CONSULT-lll
1. Start engine and warm it up to normal operating temperature.
2. Select “SELF-LEARNING CONT” in “WORK SUPPORT” mode with CONSULT-lll.
3. Clear the self-learning control coefficient by touching “CLEAR”.
Without CONSULT-lll
1. Start engine and warm it up to normal operating temperature.
2. Turn ignition switch OFF.
3. Disconnect mass air flow sensor harness connector.
4. Restart engine and let it idle for at least 5 seconds.
5. Stop engine and reconnect mass air flow sensor harness con- nector.
6. Make sure DTC P0102 is displayed.
7. Erase the DTC memory. Refer to EC-55, "
Malfunction Indicator
Lamp (MIL)".
8. Make sure DTC P0000 is displayed.
>> GO TO 14.
14.CONFIRM A/F ADJUSTMENT DATA
1. Turn ignition switch OFF and then ON.
2. Select “A/F ADJ-B1” and “A/F ADJ-B2” in “DATA MONITOR” mode with CONSULT-IIl.
3. Make sure that “0.000” is displayed on CONSULT-IIl screen.
>>INSPECTION END
BBIA0368E
Revision: March 2010 2008 QX56

EC-402
< COMPONENT DIAGNOSIS >[VK56DE]
FUEL PUMP
FUEL PUMP
DescriptionINFOID:0000000001365881
SYSTEM DESCRIPTION
*: ECM determines the start signal status by the signals of engine speed and battery voltage.
The ECM activates the fuel pump for several seconds after the ignition switch is turned ON to improve engine
startability. If the ECM receives a engine speed signal
from the camshaft position sensor (PHASE), it knows
that the engine is rotating, and causes the pump to operate. If the engine speed signal is not received when
the ignition switch is ON, the engine stalls. The EC M stops pump operation and prevents battery discharging,
thereby improving safety. The ECM does not directly drive the fuel pump. It controls the ON/OFF fuel pump
relay, which in turn controls the fuel pump.
COMPONENT DESCRIPTION
A turbine type design fuel pump is used in the fuel tank.
Diagnosis ProcedureINFOID:0000000001365884
1.CHECK OVERALL FUNCTION
1. Turn ignition switch ON.
2. Pinch fuel feed hose with two fingers.
OK or NG
OK >> INSPECTION END
NG >> GO TO 2.
2.CHECK FUEL PUMP POWER SUPPLY CIRCUIT-I
1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Turn ignition switch ON.
Sensor Input signal to ECMECM FunctionActuator
Crankshaft position sensor (POS)
Camshaft position sensor (PHASE) Engine speed*
Fuel pump control Fuel pump relay
Battery Battery voltage*
Condition Fuel pump operation
Ignition switch is turned to ON. Operates for 1 second.
Engine running and cranking Operates.
When engine is stopped Stops in 1.5 seconds.
Except as shown above Stops.
BBIA0402E
Fuel pressure pulsation should be felt on the fuel feed
hose for 1 second after igniti on switch is turned ON.
BBIA0357E
Revision: March 2010 2008 QX56

EC-426
< ECU DIAGNOSIS >[VK56DE]
ECM
ECU DIAGNOSIS
ECM
CONSULT-lll Reference Valu
e in Data Monitor ModeINFOID:0000000001351350
Remarks:
z Specification data are reference values.
z Specification data are output/input values which are detected or supplied by the ECM at the connector.
* Specification data may not be directly relate d 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 moni tors the data calculated by the ECM according to the signals
input from the camshaft position sensor and other ignition timing related sensors.
MONITOR ITEM CONDITION SPECIFICATION
ENG SPEED • Run engine and compare CONSULT-IIl value with the tachometer indica-
tion. Almost the same speed as the
tachometer indication.
MAS A/F SE-B1 See EC-75
.
B/FUEL SCHDL See EC-75
.
A/F ALPHA-B1
A/F ALPHA-B2 See
EC-75
.
COOLAN TEMP/S • Engine: After warming up More than 70°C (158 °F)
A/F SEN1 (B1)
A/F SEN1 (B2) • Engine: After warming up Maintaining engine speed at 2,000 rpm Fluctuates around 2.2 V
HO2S2 (B1)
HO2S2 (B2) • 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)
HO2S2 MNTR (B2) • 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 LEAN
←→ RICH
VHCL SPEED SE • Turn drive wheels and compare CONSULT-IIl 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 • Ignition switch: ON
(Engine stopped) Accelerator pedal: Fully released 0.5 - 1.0V
Accelerator pedal: Fully depressed 4.2 - 4.8V
ACCEL SEN 2*
1• Ignition switch: ON (Engine stopped) Accelerator pedal: Fully released 0.5 - 1.0V
Accelerator pedal: Fully depressed 4.2 - 4.8V
TP SEN 1-B1
TP SEN 2-B1 • Ignition switch: ON
(Engine stopped)
• Selector lever: D Accelerator pedal:
Fully released More than 0.36V
Accelerator pedal: Fully depressed Less than 4.75V
EVAP SYS PRES • Ignition switch: ON Approx. 1.8 - 4.8V
START SIGNAL • Ignition switch: ON → START → ON OFF → ON → OFF
CLSD THL POS • Ignition switch: ON
(Engine stopped) Accelerator pedal: Fully released ON
Accelerator pedal: Slightly depressed OFF
AIR COND SIG • Engine: After warming up, idle the
engine Air conditioner switch: OFF
OFF
Air conditioner switch: ON
(Compressor operates.) ON
P/N POSI SW • Ignition switch: ON Selector lever: P or N
ON
Selector lever: Except above OFF
PW/ST SIGNAL • Engine: After warming up, idle the
engine Steering wheel: Not being turned
(Forward direction)
OFF
Steering wheel: Being turned ON
Revision: March 2010 2008 QX56

ECM
EC-429
< ECU DIAGNOSIS > [VK56DE]
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ECM Harness Connector Terminal LayoutINFOID:0000000001351346
ECM Terminal and Reference ValueINFOID:0000000001351347
PREPARATION
ECM is located in the engine room passenger side behind battery.
ECM INSPECTION TABLE
Specification data are reference values and are measured between each terminal and ground.
Pulse signal is measured by CONSULT-IIl.
CAUTION:
Do not use ECM ground terminals wh
en measuring input/output voltage. Doing so may result in dam-
age to the ECMs transistor. Use a ground ot her than ECM terminals, such as the ground.
PBIB3368E
BBIA0386E
TER-
MI-
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NO. WIRE
COLOR ITEM
CONDITION DATA (DC Voltage)
1 B ECM ground [Engine is running]
• Idle speedBody ground
2 LG/B A/F sensor 1 heater (bank 1) [Engine is running]
•
Warm-up condition
• Idle speed (More than 140 seconds after starting en-
gine) Approximately 2.9 - 8.8V
3L Throttle contro
l motor relay
power supply [Ignition switch: ON] BATTERY VOLTAGE
(11 - 14V)
4 L/W Throttle cont rol motor (Close)[Ignition switch: ON]
• Engine: Stopped
• Selector lever: D
• Accelerator pedal: Fully released 0 - 14V
PBIA8148J
PBIB1104E
Revision: March 2010
2008 QX56