2007 INFINITI QX56 air condition

TROUBLE DIAGNOSIS - SPECIFICATION VALUE
EC-129
< SERVICE INFORMATION >
C
D
E
F
G
H
I
J
K
L
MA
EC
N
P O
TROUBLE DIAGNOSIS - SPECIFICATION VALUE
DescriptionINFOID:0000000003531630
The specification (SP) value indicates the tolerance of the value that is displayed in “DATA MONITOR (SPEC)”
mode of CONSULT-II during normal operation of the Engine Control System. When the value in “DATA MONI-
TOR (SPEC)” mode is within the SP value, the Engine Control System is confirmed OK. When the value in
“DATA MONITOR (SPEC)” mode is NOT within the SP value, the Engine Control System may have one or
more malfunctions.
The SP value is used to detect malfunctions that may affect the Engine Control System, but will not light the
MIL.
The SP value will be displayed for the following three items:
• B/FUEL SCHDL (The fuel injection pulse width programmed into ECM prior to any learned on board correc-
tion)
• A/F ALPHA-B1/B2 (The mean value of air-fuel ratio feedback correction factor per cycle)
• MAS A/F SE-B1 (The signal voltage of the mass air flow sensor)
Testing ConditionINFOID:0000000003531631
• Vehicle driven distance: More than 5,000 km (3,107 miles)
• Barometric pressure: 98.3 - 104.3 kPa (1.003 - 1.064 kg/cm
2 , 14.25 - 15.12 psi)
• Atmospheric temperature: 20 - 30°C (68 - 86°F)
• Engine coolant temperature: 75 - 95°C (167 - 203°F)
• Engine speed: Idle
• Transmission: Warmed-up
- After the engine is warmed up to normal operating temperature, drive vehicle until “ATF TEMP SE 1” (A/T
fluid temperature sensor signal) indicates more than 60°C (140°F).
• Electrical load: Not applied
- Rear window defogger switch, air conditioner switch, lighting switch are OFF. Steering wheel is straight
ahead.
Inspection ProcedureINFOID:0000000003531632
NOTE:
Perform “DATA MONITOR (SPEC)” mode in maximum scale display.
1. Perform EC-71, "
Basic Inspection" .
2. Confirm that the testing conditions indicated above are met.
3. Select “B/FUEL SCHDL”, “A/F ALPHA-B1”, “A/F ALPHA-B2”
and “MAS A/F SE-B1” in “DATA MONITOR (SPEC)” mode with
CONSULT-II.
4. Make sure that monitor items are within the SP value.
5. If NG, go to EC-130, "
Diagnosis Procedure" .
SEF601Z

EC-138
< SERVICE INFORMATION >
TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT
TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT
DescriptionINFOID:0000000003531634
Intermittent incidents may occur. In many cases, the malfunction resolves itself (the part or circuit function
returns to normal without intervention). It is important to realize that the symptoms described in the customer's
complaint often do not recur on (1st trip) DTC visits. Realize also that the most frequent cause of intermittent
incidents occurrences is poor electrical connections. Because of this, the conditions under which the incident
occurred may not be clear. Therefore, circuit checks made as part of the standard diagnostic procedure may
not indicate the specific malfunctioning area.
Common Intermittent Incidents Report Situations
Diagnosis ProcedureINFOID:0000000003531635
1.INSPECTION START
Erase (1st trip) DTCs. Refer to EC-49, "
Emission-related Diagnostic Information" .
>> GO TO 2.
2.CHECK GROUND TERMINALS
Check ground terminals for corroding or loose connection.
Refer to EC-143, "
Ground Inspection" .
OK or NG
OK >> GO TO 3.
NG >> Repair or replace.
3.SEARCH FOR ELECTRICAL INCIDENT
Perform GI-25, "
How to Perform Efficient Diagnosis for an Electrical Incident", “INCIDENT SIMULATION
TESTS”.
OK or NG
OK >> GO TO 4.
NG >> Repair or replace.
4.CHECK CONNECTOR TERMINALS
Refer to GI-22, "
How to Check Terminal", “HOW TO PROBE CONNECTORS”, “How to Check Enlarged Con-
tact Spring of Terminal”.
OK or NG
OK >>INSPECTION END
NG >> Repair or replace connector.
STEP in Work Flow Situation
2 The CONSULT-II is used. The SELF-DIAG RESULTS screen shows time data other than [0] or [1t].
3 or 4 The symptom described by the customer does not recur.
5 (1st trip) DTC does not appear during the DTC Confirmation Procedure.
10 The Diagnostic Procedure for PXXXX does not indicate the malfunctioning area.

EC-140
< SERVICE INFORMATION >
POWER SUPPLY AND GROUND CIRCUIT
Diagnosis Procedure
INFOID:0000000003531637
1.INSPECTION START
Start engine.
Is engine running?
Ye s o r N o
Ye s > > G O T O 8 .
No >> GO TO 2.
2.CHECK ECM POWER SUPPLY CIRCUIT-I
1. Turn ignition switch OFF and then ON.
2. Check voltage between ECM terminal 109 and ground with
CONSULT-II or tester.
OK or NG
OK >> GO TO 4.
NG >> GO TO 3.
3.DETECT MALFUNCTIONING PART
Check the following.
• 10A fuse
• Harness for open or short between ECM and fuse
>> Repair harness or connectors.
4.CHECK GROUND CONNECTIONS
1. Turn ignition switch OFF.
2. Loosen and retighten three ground screws on the body.
TER-
MI-
NAL
NO.WIRE
COLORITEM CONDITION DATA (DC Voltage)
1 B ECM ground[Engine is running]
• Idle speedBody ground
109 L/W Ignition switch[Ignition switch: OFF]0V
[Ignition switch: ON]BATTERY VOLTAGE
(11 - 14V)
111 W / BECM relay
(Self shut-off)[Engine is running]
[Ignition switch: OFF]
• For a few seconds after turning ignition
switch OFF0 - 1.5V
[Ignition switch: OFF]
• More than a few seconds after turning igni-
tion switch OFFBATTERY VOLTAGE
(11 - 14V)
11 5
11 6B
B/WECM ground[Engine is running]
• Idle speedBody ground
11 9
120BR
BRPower supply for ECM[Ignition switch: ON]BATTERY VOLTAGE
(11 - 14V)
Voltage: Battery voltage
MBIB0015E

EC-150
< SERVICE INFORMATION >
DTC P0011, P0021 IVT CONTROL
Intake valve timing control position sensors are located in the front of
cylinder heads in both bank 1 and bank 2.
This sensor uses a Hall IC.
The cam position is determined by the intake camshaft sprocket con-
cave (in three places). The ECM provides feedback to the intake
valve timing control for appropriate target valve open-close timing
according to drive conditions based on detected cam position.
CONSULT-II Reference Value in Data Monitor ModeINFOID:0000000003531649
Specification data are reference values.
On Board Diagnosis LogicINFOID:0000000003531650
FA I L - S A F E M O D E
When the malfunction is detected, the ECM enters fail-safe mode.
DTC Confirmation ProcedureINFOID:0000000003531651
CAUTION:
Always drive at a safe speed.
NOTE:
•If DTC P0011 or P0021 is displayed with DTC P0075, P0081, P1140 or P1145, first perform the trouble
diagnosis for EC-178
or EC-457.
SEF359Z
MONITOR ITEM CONDITION SPECIFICATION
INT/V TIM (B1)
INT/V TIM (B2)• Engine: After warming up
• Selector lever: P or N
• Air conditioner switch: OFF
•No loadIdle−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 loadIdle 0% - 2%
2,000 rpm Approx. 25% - 50%
DTC No. Trouble diagnosis name Detecting condition Possible cause
P0011
0011
(Bank 1)
Intake valve timing control
performanceAThe alignment of the intake valve timing
control has been misresistered.• Harness or connectors
(Intake valve timing control solenoid
valve circuit is open or shorted.)
• Harness or connectors
(Intake valve timing control position
sensor circuit is open or shorted.)
• Intake valve timing control solenoid
valve
• Intake valve timing control position
sensor
• Crankshaft position sensor (POS)
• Camshaft position sensor (PHASE)
• Accumulation of debris to the signal
pick-up portion of the camshaft
sprocket
• Timing chain installation
• Foreign matter caught in the oil
groove for intake valve timing control P0021
0021
(Bank 2)BThere is a gap between angle of target and
phase-control angle degree.
Detected items Engine operating condition in fail-safe mode
Intake valve timing control The signal is not energized to the solenoid valve and the valve control does not function

DTC P0031, P0032, P0051, P0052 A/F SENSOR 1 HEATER
EC-163
< SERVICE INFORMATION >
C
D
E
F
G
H
I
J
K
L
MA
EC
N
P O
DTC P0031, P0032, P0051, P0052 A/F SENSOR 1 HEATER
DescriptionINFOID:0000000003531656
SYSTEM DESCRIPTION
The ECM performs ON/OFF duty control of the A/F sensor 1 heater corresponding to the engine operating
condition to keep the temperature of A/F sensor 1 element at the specified range.
CONSULT-II Reference Value in Data Monitor ModeINFOID:0000000003531657
Specification data are reference values.
On Board Diagnosis LogicINFOID:0000000003531658
DTC Confirmation ProcedureINFOID:0000000003531659
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 between 10.5V and 16V at
idle.
WITH CONSULT-II
1. Turn ignition switch ON and select “DATA MONITOR” mode with
CONSULT-II.
2. Start engine and let it idle for at least 10 seconds.
3. If 1st trip DTC is detected, go to EC-167, "
Diagnosis Procedure".
Sensor Input Signal to ECM ECM function Actuator
Camshaft position sensor (PHASE)
Crankshaft position sensor (POS)Engine speed
Air fuel ratio (A/F) sensor 1
heater controlAir fuel ratio (A/F) sensor 1
heater
Mass air flow sensor Amount of intake air
MONITOR ITEM CONDITION SPECIFICATION
A/F S1 HTR (B1)
A/F S1 HTR (B2)• Engine: After warming up, idle the engine 4 - 100%
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P0031
0031
(Bank 1)
Air fuel ratio (A/F) sensor
1 heater control circuit lowThe current amperage in the air fuel ratio (A/F) sen-
sor 1 heater circuit is out of the normal range.
(An excessively low voltage signal is sent to ECM
through the air fuel ratio (A/F) sensor 1 heater.)• Harness or connectors
(The A/F sensor 1 heater circuit is
open or shorted.)
• A/F sensor 1 heater P0051
0051
(Bank 2)
P0032
0032
(Bank 1)Air fuel ratio (A/F) sensor
1 heater control circuit
highThe current amperage in the air fuel ratio (A/F) sen-
sor 1 heater circuit is out of the normal range.
(An excessively high voltage signal is sent to ECM
through the air fuel ratio (A/F) sensor 1 heater.)• Harness or connectors
(The A/F sensor 1 heater circuit is
shorted.)
• A/F sensor 1 heater P0052
0052
(Bank 2)
SEF058Y

DTC P0031, P0032, P0051, P0052 A/F SENSOR 1 HEATER
EC-165
< SERVICE INFORMATION >
C
D
E
F
G
H
I
J
K
L
MA
EC
N
P O
Pulse signal is measured by CONSULT-II.
CAUTION:
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 P0031, P0032, P0051, P0052 A/F SENSOR 1 HEATER
EC-167
< 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:0000000003531661
1.CHECK GROUND CONNECTIONS
1. Turn ignition switch OFF.
2. Loosen and retighten three 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.CHECK AIR FUEL RATIO (A/F) SENSOR 1 POWER SUPPLY CIRCUIT
1. Disconnect air fuel ratio (A/F) sensor 1 harness connector.
2. Turn ignition switch ON.
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
BBIA0376E

EC-170
< SERVICE INFORMATION >
DTC P0037, P0038, P0057, P0058 HO2S2 HEATER
DTC P0037, P0038, P0057, P0058 HO2S2 HEATER
DescriptionINFOID:0000000003531664
SYSTEM DESCRIPTION
The ECM performs ON/OFF control of the heated oxygen sensor 2 heater corresponding to the engine speed,
amount of intake air and engine coolant temperature.
OPERATION
CONSULT-II Reference Value in Data Monitor ModeINFOID:0000000003531665
Specification data are reference values.
On Board Diagnosis LogicINFOID:0000000003531666
DTC Confirmation ProcedureINFOID:0000000003531667
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:
Sensor Input signal to ECM ECM function Actuator
Camshaft position sensor (PHASE)
Crankshaft position sensor (POS)Engine speed
Heated oxygen sensor 2
heater controlHeated oxygen sensor 2 heater
Engine coolant temperature sensor Engine coolant temperature
Mass air flow sensor Amount of intake air
Engine speed rpm Heated oxygen sensor 2 heater
Above 3,600OFF
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 loadON
MONITOR ITEM CONDITION SPECIFICATION
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 loadON
• Engine speed: Above 3,600 rpm OFF
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P0037
0037
(Bank 1)
Heated oxygen sensor 2
heater control circuit lowThe current amperage in the heated oxygen sen-
sor 2 heater circuit is out of the normal range.
(An excessively low voltage signal is sent to ECM
through the heated oxygen sensor 2 heater.)• Harness or connectors
(The heated oxygen sensor 2 heater
circuit is open or shorted.)
• Heated oxygen sensor 2 heater P0057
0057
(Bank 2)
P0038
0038
(Bank 1)
Heated oxygen sensor 2
heater control circuit highThe current amperage in the heated oxygen sen-
sor 2 heater circuit is out of the normal range.
(An excessively high voltage signal is sent to ECM
through the heated oxygen sensor 2 heater.)• Harness or connectors
(The heated oxygen sensor 2 heater
circuit is shorted.)
• Heated oxygen sensor 2 heater P0058
0058
(Bank 2)