2007 INFINITI QX56 air condition

EC-588
< SERVICE INFORMATION >
DTC P2A00, P2A03 A/F SENSOR 1
DTC P2A00, P2A03 A/F SENSOR 1
Component DescriptionINFOID:0000000003532141
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 measurement = 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).
CONSULT-II Reference Value in Data Monitor ModeINFOID:0000000003532142
Specification data are reference values.
On Board Diagnosis LogicINFOID:0000000003532143
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:0000000003532144
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.
TESTING CONDITION:
Before performing the following procedure, confirm that battery voltage is more than 11V at idle.
WITH CONSULT-II
1. Start engine and warm it up to normal operating temperature.
2. Turn ignition switch OFF and wait at least 10 seconds.
PBIB3353E
PBIB3354E
MONITOR ITEM CONDITION SPECIFICATION
A/F SEN1 (B1)
A/F SEN1 (B2)• Engine: After warming up Maintaining engine speed at 2,000 rpm Fluctuates around 2.2V
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)

DTC P2A00, P2A03 A/F SENSOR 1
EC-591
< SERVICE INFORMATION >
C
D
E
F
G
H
I
J
K
L
MA
EC
N
P O
Do not use ECM ground terminals when measuring input/output voltage. Doing so may result in dam-
age to the ECM's transistor. Use a ground other than ECM terminals, such as the ground.
: Average voltage for pulse signal (Actual pulse signal can be confirmed by oscilloscope.)TER-
MI-
NAL
NO.WIRE
COLORITEM CONDITION DATA (DC Voltage)
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
35 BR/R A/F sensor 1 (bank 1)[Engine is running]
•Warm-up condition
• Engine speed: 2,000 rpmApproximately 1.8V
Output voltage varies with air fuel
ratio.
56 BR/G A/F sensor 1 (bank 1)[Ignition switch: ON]Approximately 2.2V
PBIA8148J

DTC P2A00, P2A03 A/F SENSOR 1
EC-593
< SERVICE INFORMATION >
C
D
E
F
G
H
I
J
K
L
MA
EC
N
P O
: Average voltage for pulse signal (Actual pulse signal can be confirmed by oscilloscope.)
Diagnosis ProcedureINFOID:0000000003532146
1.CHECK GROUND CONNECTIONS
1. Turn ignition switch OFF.
2. Loosen and retighten two ground screws on the body.
Refer to EC-143, "
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.
>> GO TO 3.
3.CHECK FOR INTAKE AIR LEAK
1. Start engine and run it at idle.
TER-
MI-
NAL
NO.WIRE
COLORITEM CONDITION DATA (DC Voltage)
16 G/L A/F sensor 1 (bank 2)[Engine is running]
•Warm-up condition
• Engine speed: 2,000 rpmApproximately 1.8V
Output voltage varies with air fuel
ratio.
24
43GR/G
GR/GA/F sensor 1 heater (bank 2)[Engine is running]
•Warm-up condition
• Idle speed
(More than 140 seconds after starting en-
gine)Approximately 2.9 - 8.8V
75 L/P A/F sensor 1 (bank 2)[Ignition switch: ON]Approximately 2.2V
PBIA8148J
BBIA0354E
Tightening torque: 50 N-m (5.1 kg-m, 37 ft-lb)
BBIA0375E

EC-602
< SERVICE INFORMATION >
ASCD BRAKE SWITCH
>> Repair open circuit or short to ground or short to power in harness or connectors.
9.CHECK STOP LAMP SWITCH INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT
1. Disconnect ECM harness connector.
2. Check harness continuity between ECM terminal 101 and stop lamp switch terminal 4.
Refer to Wiring Diagram.
3. Also check harness for short to ground and short to power.
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 STOP LAMP SWITCH
Refer to EC-602, "
Component Inspection" .
OK or NG
OK >> GO TO 11.
NG >> Replace stop lamp switch.
11 .CHECK INTERMITTENT INCIDENT
Refer to EC-138
.
>>INSPECTION END
Component InspectionINFOID:0000000003532152
ASCD BRAKE SWITCH
1. Turn ignition switch OFF.
2. Disconnect ASCD brake switch harness connector.
3. Check harness continuity between ASCD brake switch terminals
1 and 2 under the following conditions.
If NG, adjust ASCD brake switch installation, refer to BR-5
, and
perform step 3 again.
STOP LAMP SWITCH
1. Turn ignition switch OFF.
2. Disconnect stop lamp switch harness connector.
3. Check harness continuity between stop lamp switch terminals 3
and 4 under the following conditions.
If NG, adjust stop lamp switch installation, refer to BR-5
, and
perform step 3 again.Continuity should exist.
Condition Continuity
Brake pedal: Fully released Should exist.
Brake pedal: Slightly depressed Should not exist.
PBIB1536E
Condition Continuity
Brake pedal: Fully released Should not exist.
Brake pedal: Slightly depressed Should exist.
PBIB2103E

EC-608
< SERVICE INFORMATION >
FUEL INJECTOR
FUEL INJECTOR
Component DescriptionINFOID:0000000003532160
The fuel injector is a small, precise solenoid valve. When the ECM
supplies a ground to the fuel injector circuit, the coil in the fuel injec-
tor is energized. The energized coil pulls the ball valve back and
allows fuel to flow through the fuel injector into the intake manifold.
The amount of fuel injected depends upon the injection pulse dura-
tion. Pulse duration is the length of time the fuel injector remains
open. The ECM controls the injection pulse duration based on
engine fuel needs.
CONSULT-II Reference Value in Data Monitor ModeINFOID:0000000003532161
Specification data are reference values.
SEF375Z
MONITOR ITEM CONDITION SPECIFICATION
B/FUEL SCHDL See EC-129
.
INJ PULSE-B1
INJ PULSE-B2• Engine: After warming up
• Air conditioner switch: OFF
• Selector lever: P or N
•No loadIdle 2.0 - 2.8 msec
2,000 rpm 1.9 - 2.9 msec

EC-622
< SERVICE INFORMATION >
ICC BRAKE SWITCH
Without CONSULT-II
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 ACS-34
.
OK or NG
OK >> GO TO 4.
NG >> Repair or replace.
4.CHECK ICC BRAKE HOLD RELAY 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-II 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.
CONDITION VOLTAGE
Brake pedal: Fully released Approximately 0V
Brake pedal: Slightly depressed Battery voltage
PBIB1537E
BBIA0471E
Voltage: Battery voltage
MBIB0059E

EC-638
< SERVICE INFORMATION >
REFRIGERANT PRESSURE SENSOR
REFRIGERANT PRESSURE SENSOR
Component DescriptionINFOID:0000000003532182
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.
BBIA0445E
PBIB2657E

EC-640
< SERVICE INFORMATION >
REFRIGERANT PRESSURE SENSOR
Diagnosis Procedure
INFOID:0000000003532184
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 switch ON.
3. Check voltage between ECM terminal 70 and ground with CON-
SULT-II or tester.
OK or NG
OK >>INSPECTION END
NG >> GO TO 2.
2.CHECK GROUND CONNECTIONS
1. Turn A/C switch and blower switch OFF.
2. Turn ignition switch OFF.
3. Loosen and retighten three ground screws on the body.
Refer to EC-143, "
Ground Inspection" .
OK or NG
OK >> GO TO 3.
NG >> Repair or replace ground connections.
3.CHECK REFRIGERANT PRESSURE SENSOR POWER SUPPLY CIRCUIT
TER-
MI-
NAL
NO.WIRE
COLORITEM CONDITION DATA (DC Voltage)
49 R/YSensor power supply
(Refrigerant pressure sen-
sor)[Ignition switch: ON]Approximately 5V
67 B Sensor ground[Engine is running]
•Warm-up condition
• Idle speedApproximately 0V
70 B/W Refrigerant pressure sensor[Engine is running]
•Warm-up condition
• Both A/C switch and blower switch: ON
(Compressor: Operates)1.0 - 4.0V
Voltage: 1.0 - 4.0V
PBIB1188E
BBIA0354E