air condition INFINITI QX56 2009 Factory Service Manual

EC-368
< COMPONENT DIAGNOSIS >[VK56DE]
P2127, P2128 APP SENSOR
>>
INSPECTION END
Component InspectionINFOID:0000000003771688
ACCELERATOR PEDAL POSITION SENSOR
1. Reconnect all harness connectors disconnected.
2. Turn ignition switch ON.
3. Check voltage between ECM terminals 106 (APP sensor 1 sig-
nal), 98 (APP sensor 2 signal) and ground under the following
conditions.
4. If NG, replace accelerator pedal assembly and go to next step.
5. Perform EC-18, "Accelerator Pedal Released Position Learning"
.
6. Perform EC-18, "Throttle Valve Closed Position Learning"
.
7. Perform EC-18, "Idle Air Volume Learning"
.
Terminal Accelerator pedal Voltage
106
(Accelerator pedal position
sensor 1) Fully released 0.5 - 1.0V
Fully depressed 4.2 - 4.8V
98
(Accelerator pedal position
sensor 2) Fully released 0.25 - 0.5V
Fully depressed 2.0 - 2.5V
MBIB0023E
Revision: December 20092009 QX56

EC-376
< COMPONENT DIAGNOSIS >[VK56DE]
P2138 APP SENSOR
OK or NG
OK >> GO TO 10.
NG >> Repair open circuit or short to ground or short to power in harness or connectors.
10.CHECK ACCELERATOR PEDAL POSITION SENSOR
Refer to EC-376, "Component Inspection"
.
OK or NG
OK >> GO TO 12.
NG >> GO TO 11.
11 .REPLACE ACCELERATOR PEDAL ASSEMBLY
1. Replace the accelerator pedal assembly.
2. Perform EC-18, "Accelerator Pedal Released Position Learning"
.
3. Perform EC-18, "Throttle Valve Closed Position Learning"
.
4. Perform EC-18, "Idle Air Volume Learning"
.
>> INSPECTION END
12.CHECK INTERMITTENT INCIDENT
Refer to GI-35, "How to Check Terminal"
and GI-38, "Intermittent Incident".
>> INSPECTION END
Component InspectionINFOID:0000000003771698
ACCELERATOR PEDAL POSITION SENSOR
1. Reconnect all harness connectors disconnected.
2. Turn ignition switch ON.
3. Check voltage between ECM terminals 106 (APP sensor 1 sig-
nal), 98 (APP sensor 2 signal) and ground under the following
conditions.
4. If NG, replace accelerator pedal assembly and go to next step.
5. Perform EC-18, "Accelerator Pedal Released Position Learning"
.
6. Perform EC-18, "Throttle Valve Closed Position Learning"
.
7. Perform EC-18, "Idle Air Volume Learning"
.
Terminal Accelerator pedal Voltage
106
(Accelerator pedal position
sensor 1) Fully released 0.5 - 1.0V
Fully depressed 4.2 - 4.8V
98
(Accelerator pedal position
sensor 2) Fully released 0.25 - 0.5V
Fully depressed 2.0 - 2.5V
MBIB0023E
Revision: December 20092009 QX56

P2A00, P2A03 A/F SENSOR 1EC-377
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P2A00, P2A03 A/F SENSOR 1
Component DescriptionINFOID:0000000003771699
The air fuel ratio (A/F) sensor 1 is a planar one-cell limit current sen-
sor. The sensor element of the A/F sensor 1 is composed an elec-
trode layer, which transports ions. It has a heater in the element.
The sensor is capable of precise m
easurement = 1, but also in the
lean and rich range. Together with its control electronics, the sensor
outputs a clear, continuous signal throughout a wide range.
The exhaust gas components diffuse through the diffusion layer at
the sensor cell. An electrode layer is applied voltage, and this current
relative oxygen density in lean. Also this current relative hydrocar-
bon density in rich.
Therefore, the A/F sensor 1 is able to indicate air fuel ratio by this
electrode layer of current. In addition, a heater is integrated in the
sensor to ensure the required operating temperature of about 800 °C
(1,472 °F).
On Board Diagnosis LogicINFOID:0000000003771700
To judge the malfunction, the A/F signal computed by ECM from the A/F sensor 1 signal is monitored not to be
shifted to LEAN side or RICH side.
DTC Confirmation ProcedureINFOID:0000000003771701
NOTE:
If DTC Confirmation Procedure has been previously conduc ted, always perform the following before conduct-
ing the next step.
1. Turn ignition swich OFF and wait at least 10 seconds.
2. Turn ignition swich ON.
3. Turn ignition swich OFF and wait at least 10 seconds.
TESTING CONDITION:
Before performing the following procedure, confirm that battery voltage is more than 11V at idle.
WITH CONSULT-IIl
1. Start engine and warm it up to normal operating temperature.
2. Turn ignition switch OFF and wait at least 10 seconds.
3. Turn ignition switch ON and select “SELF-LEARNING CONT” in “WORK SUPPORT” mode with CON-
SULT-IIl.
4. Clear the self-learning coefficient by touching “CLEAR”.
PBIB3353E
PBIB3354E
DTC No. Trouble diagnosis name DTC detecting condition Possible Cause
P2A00
2A00
(Bank 1) Air fuel ratio (A/F) sensor 1
circuit range/performance  The output voltage computed by ECM from the
A/F sensor 1 signal is shifted to the lean side for
a specified period.
 The A/F signal computed by ECM from the A/F
sensor 1 signal is shifted to the rich side for a
specified period.  A/F sensor 1
 A/F sensor 1 heater
 Fuel pressure
 Fuel injector
 Intake air leaks
P2A03
2A03
(Bank 2)
Revision: December 20092009 QX56

EC-384
< COMPONENT DIAGNOSIS >[VK56DE]
ASCD BRAKE SWITCH
OK or NG
OK >>
INSPECTION END
NG >> GO TO 7.
3.CHECK ASCD BRAKE SWITCH POWER SUPPLY CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect ASCD brake switch harness connector.
3. Turn ignition switch ON.
4. Check voltage between ASCD brake switch terminal 1 and ground with CONSULT-IIl or tester.
OK or NG
OK >> GO TO 5.
NG >> GO TO 4.
4.DETECT MALFUNCTIONING PART
Check the following.
 Harness connectors M31, E152
 Fuse block (J/B) connector M4
 10A fuse
 Harness for open or short between ASCD brake switch and fuse
>> Repair open circuit or short to ground or short to power in harness or connectors.
5.CHECK ASCD BRAKE SWITCH INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Check harness continuity between ECM terminal 108 and ASCD brake switch terminal 2. Refer to Wiring Diagram.
CONDITION VOLTAGE
Brake pedal: Fully released Approximately 0V
Brake pedal: Slightly depressed Battery voltage
PBIB1537E
BBIA0373E
Voltage: Battery voltage
PBIB0857E
Continuity should exist.
Revision: December 20092009 QX56

EC-400
< COMPONENT DIAGNOSIS >[VK56DE]
ICC BRAKE SWITCH
Check voltage between ECM terminal 101 and ground under the fol-
lowing conditions.
OK or NG
OK >>
INSPECTION END
NG >> GO TO 10.
3.CHECK DTC WITH ICC UNIT
Refer to CCS-18
.
OK or NG
OK >> GO TO 4.
NG >> Repair or replace.
4.CHECK ICC BRAKE HOLD RE LAY POWER SUPPLY CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect ICC brake hold relay.
3. Turn ignition switch ON.
4. Check voltage between ICC brake hold relay terminal 4 and ground with CONSULT-IIl or tester.
OK or NG
OK >> GO TO 6.
NG >> GO TO 5.
5.DETECT MALFUNCTIONING PART
Check the following.
 Harness connectors M31, E152
 Fuse block (J/B) connector M4
 10A fuse
 Harness for open or short between ICC brake hold relay and fuse
>> Repair open circuit or short to ground or short to power in harness or connectors.
6.CHECK ICC BRAKE SWITCH POWER SUPPLY CIRCUIT
CONDITION VOLTAGE
Brake pedal: Fully released Approximately 0V
Brake pedal: Slightly depressed Battery voltage
PBIB1537E
BBIA0471E
Voltage: Battery voltage
MBIB0059E
Revision: December 20092009 QX56

EC-414
< COMPONENT DIAGNOSIS >[VK56DE]
POSITIVE CRANKCASE VENTILATION
POSITIVE CRANKCASE VENTILATION
DescriptionINFOID:0000000003771727
SYSTEM DESCRIPTION
This system returns blow-by gas to the intake manifold.
The positive crankcase ventilation (PCV) valve is prov
ided to conduct crankcase blow-by gas to the intake
manifold. During partial throttle operation of the engine, the intake manifold sucks the blow-by gas through the
PCV valve. Normally, the capacity of the valve is suff icient to handle any blow-by and a small amount of venti-
lating air. The ventilating air is drawn from the air inle t tubes into the crankcase. In this process the air passes
through the hose connecting air inlet tubes to rocker cover. Under full-throttle condition, the manifold vacuum
is insufficient to draw the blow-by flow through t he valve. The flow goes through the hose connection in the
reverse direction.
On vehicles with an excessively high blow-by, the valve does not
meet the requirement. This is because some of the flow will go
through the hose connection to the air inlet tubes under all condi-
tions.
Component InspectionINFOID:0000000003771728
PCV (POSITIVE CRANKCASE VENTILATION) VALVE
With engine running at idle, remove PCV valve from rocker cover. A
properly working valve makes a hissing noise as air passes through
it. A strong vacuum should be felt immediately when a finger is
placed over valve inlet.
PCV VALVE VENTILATION HOSE
PBIB0062E
PBIB1588E
PBIB1589E
Revision: December 20092009 QX56

EC-416
< COMPONENT DIAGNOSIS >[VK56DE]
REFRIGERANT PRESSURE SENSOR
REFRIGERANT PRESSURE SENSOR
Component DescriptionINFOID:0000000003771729
The refrigerant pressure sensor is
installed at the condenser of the
air conditioner system. The sensor uses an electrostatic volume
pressure transducer to convert refrigerant pressure to voltage. The
voltage signal is sent to ECM, and ECM controls cooling fan system.
Diagnosis ProcedureINFOID:0000000003771730
1.CHECK REFRIGERANT PRESSURE SENSOR OVERALL FUNCTION
1. Start engine and warm it up to normal operating temperature.
2. Turn A/C switch and blower fan switch ON.
3. Check voltage between ECM terminal 70 and ground with CON- SULT-IIl or tester.
OK or NG
OK >> INSPECTION END
NG >> GO TO 2.
2.CHECK GROUND CONNECTIONS
1. Turn A/C switch and blower fan switch OFF.
2. Turn ignition switch OFF.
3. Loosen and retighten three ground screws on the body.
BBIA0445E
PBIB2657E
Voltage: 1.0 - 4.0V
PBIB1188E
Revision: December 20092009 QX56

ECM
EC-419
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ECU DIAGNOSIS
ECM
CONSULT-lll Reference Valu
e in Data Monitor ModeINFOID:0000000003771731
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 relat ed to their components signals/values/operations.
i.e. Adjust ignition timing with a timi ng light before monitoring IGN TIMING, because the monitor may show the specification data in spite of the
ignition timing not being adjusted to the s pecification data. This IGN TIMING monitors the data calculated by the ECM according to the signals
input from the camshaft position sensor an d 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-74
.
B/FUEL SCHDL See EC-74
.
A/F ALPHA-B1
A/F ALPHA-B2 See
EC-74
.
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*
1Ignition 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: December 20092009 QX56

EC-420
< ECU DIAGNOSIS >[VK56DE]
ECM
LOAD SIGNAL  Ignition switch: ONRear window defogger switch is ON
and/or lighting switch is in 2nd.
ON
Rear window defogger switch is OFF
and lighting switch is OFF. OFF
IGNITION SW  Ignition switch: ON → OFF → ON ON → OFF → ON
HEATER FAN SW  Engine: After warming up, idle the
engine Heater fan control switch: ON ON
Heater fan control switch: OFF OFF
BRAKE SW  Ignition switch: ON Brake pedal: Fully released OFF
Brake pedal: Slightly depressed ON
INJ PULSE-B1
INJ PULSE-B2  Engine: After warming up
 Selector lever: P or N
 Air conditioner switch: OFF
No load Idle 2.0 - 2.8 msec
2,000 rpm 1.9 - 2.9 msec
IGN TIMING  Engine: After warming up
 Selector lever: P or N
 Air conditioner switch: OFF
No load Idle 10
° - 20 ° BTDC
2,000 rpm 25 ° - 45 ° BTDC
CAL/LD VALUE  Engine: After warming up
 Selector lever: P or N
 Air conditioner switch: OFF
No load Idle 14% - 33%
2,500 rpm 12% - 25%
MASS AIRFLOW  Engine: After warming up
 Selector lever: P or N
 Air conditioner switch: OFF
No load Idle 3.0 - 9.0 g·m/s
2,500 rpm 9.0 - 28.0 g·m/s
PURG VOL C/V  Engine: After warming up
 Selector lever: P or N
 Air conditioner switch: OFF
No load Idle
(Accelerator pedal: Not depressed
even slightly, after engine starting.)
0%
2,000 rpm —
INT/V TIM (B1)
INT/V TIM (B2)  Engine: After warming up
 Selector lever: P or N
 Air conditioner switch: OFF
No load Idle
−5 ° - 5 °CA
2,000 rpm Approx. 0 ° - 20 °CA
INT/V SOL (B1)
INT/V SOL (B2)  Engine: After warming up
 Selector lever: P or N
 Air conditioner switch: OFF
No load Idle 0% - 2%
2,000 rpm Approx. 25% - 50%
AIR COND RLY  Engine: After warming up, idle the
engine Air conditioner switch: OFF OFF
Air conditioner switch: ON
(Compressor: Operates)
ON
FUEL PUMP RLY
 For 1 second after turning ignition switch ON
 Engine running or cranking ON
 Except above conditions OFF
VENT CONT/V  Ignition switch: ON OFF
THRTL RELAY  Ignition switch: ON ON
COOLING FAN  Engine: After warming up, idle the
engine
 Air conditioner switch: OFF Engine coolant temperature: 99
°C
(210 °F) or less OFF
Engine coolant temperature: 100 °C
(212 °F) or more HI
HO2S2 HTR (B1)
HO2S2 HTR (B2)  Engine speed: Below 3,600 rpm 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 ON
 Engine speed: Above 3,600 rpm OFF
MONITOR ITEM CONDITION SPECIFICATION
Revision: December 20092009 QX56

ECM
EC-421
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*1: Accelerator pedal position sensor 2 signal and throttle position sensor 2 signal are converted by ECM internally. Thus, the
y differ
from ECM terminals voltage signal.
*2: Before measuring the terminal voltage, confirm the battery is fully charged. Refer to PG-77
.
I/P PULLY SPD  Vehicle speed: More than 20 km/h (12 MPH)
Almost the same speed as the
tachometer indication
VEHICLE SPEED  Turn drive wheels and compare CONSULT-IIl value with the speedometer
indication. Almost the same speed as the
speedometer indication
TRVL AFTER MIL  Ignition switch: ON Vehicle has traveled after MIL has
turned ON.0 - 65,535 km
(0 - 40,7
23 mile)
A/F S1 HTR (B1)
A/F S1 HTR (B2)  Engine: After warming up, idle the engine 4 - 100%
AC PRESS SEN Engine: Idle
 Both A/C switch and blower fan switch: ON (Compressor operates.)
1.0 - 4.0V
VHCL SPEED SE  Turn drive wheels and compare CONSULT-IIl value with the speedometer
indication. Almost the same speed as the
speedometer indication
SET VHCL SPD  Engine: Running ASCD: Operating. The preset vehicle speed is dis-
played.
MAIN SW  Ignition switch: ON MAIN switch: Pressed ON
MAIN switch: Released OFF
CANCEL SW  Ignition switch: ON CANCEL switch: Pressed ON
CANCEL switch: Released OFF
RESUME/ACC SW  Ignition switch: ON RESUME/ACCELERATE switch:
Pressed
ON
RESUME/ACCELERATE switch: Re-
leased OFF
SET SW  Ignition switch: ON SET/COAST switch: Pressed ON
SET/COAST switch: Released OFF
DIST SW  Ignition switch: ON DISTANCE switch: Pressed ON
DISTANCE switch: Released OFF
BRAKE SW1  Ignition switch: ON Brake pedal: Fully released ON
Brake pedal: Slightly depressed OFF
BRAKE SW2  Ignition switch: ON Brake pedal: Fully released OFF
Brake pedal: Slightly depressed ON
CRUISE LAMP  Ignition switch: ON MAIN switch: Pressed at the 1st time
→
at the 2nd time ON
→ OFF
SET LAMP  MAIN switch: ON
 Vehicle speed: Between 40 km/h
(25 MPH) and 144 km/h (89
MPH) ASCD: Operating ON
ASCD: Not operating OFF
ALT DUTY  Engine: Idle 0 - 80%
BAT CUR SEN  Engine speed: Idle
 Battery: Fully charged*
2
 Selector lever: P or N
 Air conditioner switch: OFF
 No load Approx. 2,600 - 3,500mV
ALT DUTY SIG  Power generation voltage variable control: Operating ON
 Power generation voltage variable control: Not operating OFF
MONITOR ITEM CONDITION SPECIFICATION
Revision: December 20092009 QX56