2008 INFINITI FX35 air condition

EC-666
< SERVICE INFORMATION >[VK45DE]
TROUBLE DIAGNOSIS
TROUBLE DIAGNOSIS
Trouble Diagnosis IntroductionINFOID:0000000001326523
INTRODUCTION
The engine has an ECM to control major systems such as fuel con-
trol, ignition control, idle air control system, etc. The ECM accepts
input signals from sensors and instantly drives actuators. It is essen-
tial that both input and output signals are proper and stable. At the
same time, it is important that there are no malfunctions such as vac-
uum leaks, fouled spark plugs, or
other malfunctions with the engine.
It is much more difficult to diagnose an incident that occurs intermit-
tently rather than continuously. Most intermittent incidents are
caused by poor electric connections or improper wiring. In this case,
careful checking of suspected circuits may help prevent the replace-
ment of good parts.
A visual check only may not find the cause of the incidents. A road
test with CONSULT-III (or GST) or a circuit tester connected should
be performed. Follow the Work Flow on "Work Flow".
Before undertaking actual checks, take a few minutes to talk with a
customer who approaches with a dr iveability complaint. The cus-
tomer can supply good information about such incidents, especially
intermittent ones. Find out what symptoms are present and under
what conditions they occur. A Di agnostic Worksheet like the example
on "Worksheet Sample" should be used.
Start your diagnosis by looking fo r conventional malfunctions first.
This will help troubleshoot driveability malfunctions on an electroni-
cally controlled engine vehicle.
WORK FLOW
MEF036D
SEF233G
SEF234G
3AA93ABC3ACD3AC03ACA3AC03AC63AC53A913A773A893A873A873A8E3A773A983AC73AC93AC03AC3
3A893A873A873A8F3A773A9D3AAF3A8A3A8C3A863A9D3AAF3A8B3A8C

EC-672
< SERVICE INFORMATION >[VK45DE]
TROUBLE DIAGNOSIS
 When there is an open circuit on MIL circuit, the ECM c
annot warn the driver by lighting up MIL when there
is malfunction on engine control system.
Therefore, when electrical controlled throttle and pa rt of ECM related diagnoses are continuously detected
as NG for 5 trips, ECM warns the driver that engi ne control system malfunctions and MIL circuit is open by
means of operating fail-safe function.
The fail-safe function also operates when above diagnos es except MIL circuit are detected and demands the
driver to repair the malfunction.
DTC No. Detected items Engine operating condition in fail-safe mode
P0102
P0103 Mass air flow sensor circuit Engine speed will not rise more than 2,400 rpm due to the fuel cut.
P0117
P0118 Engine coolant tempera-
ture sensor circuit Engine coolant temperature will be determined by ECM based on the following conditions.
CONSULT-III displays the engine coolant temperature decided by ECM.
Condition Engine coolant temperature decided
(CONSULT-III display)
Just as ignition switch is turned ON
or START 40
°C (104 °F)
Approx. 4 minutes or more after
engine starting. 80
°C (176 °F)
Except as shown above 40 - 80
°C (104 - 176 °F)
(Depends on the time)
When the fail-safe system for engine coolant temperature sensor is activated, the cooling
fan operates while engine is running.
P0122
P0123
P0222
P0223
P2135 Throttle position sensor 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.
P0643 Sensor power supply ECM stops the electric throttle control actuator control, throttle valve is maintained at a fixed opening (approx. 5 degrees) by the return spring.
P2100
P2103 Throttle control motor relay ECM stops the electric throttle control actuator control, throttle valve is maintained at a
fixed opening (approx. 5 degrees) by the return spring.
P2101 Electric throttle control function ECM stops the electric throttle control actuator control, throttle valve is maintained at a
fixed opening (approx. 5 degrees) by the return spring.
P2118 Throttle control motor ECM stops the electric throttle control actuator control, throttle valve is maintained at a fixed opening (approx. 5 degrees) by the return spring.
P2119 Electric thro ttle control ac-
tuator (When electric throttle control actuator does not function properly due to the return spring
malfunction:)
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.
(When throttle valve opening angle in fail-safe mode is not in specified range:)
ECM controls the electric throttle control actuator by regulating the throttle opening to 20
degrees or less.
(When ECM detects the throttle valve is stuck open:)
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.
P2122
P2123
P2127
P2128
P2138 Accelerator pedal position
sensor
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.
Engine operating condition in fail-safe mode Engine speed will not rise more than 2,500 rpm due to the fuel cut
3AA93ABC3ACD3AC03ACA3AC03AC63AC53A913A773A893A873A873A8E3A773A983AC73AC93AC03AC3
3A893A873A873A8F3A773A9D3AAF3A8A3A8C3A863A9D3AAF3A8B3A8C

EC-674
< SERVICE INFORMATION >[VK45DE]
TROUBLE DIAGNOSIS
1 - 6: The numbers refer to the order of inspection.
(continued on next page)
SYSTEM — ENGINE MECHANICAL & OTHER
Vehicle speed signal circuit 2 3 3 3
EC-992
Power steering pressure sensor circuit 2 3 3EC-998
ECM 22333333333EC-1003,
EC-1007
Intake valve timing control solenoid valve cir-
cuit 32 13223 3
EC-754
PNP switch circuit 3 3 3 3 3 EC-1014
Refrigerant pressure sensor circuit 2 3 3 4EC-1177
Electrical load signal circuit 3EC-1147
Air conditioner circuit 223333333 3 2AT C - 3 2
VIAS control solenoid valve circuit 1EC-1080
ABS actuator and electric unit (control unit) 4EC-1028
SYMPTOM
Reference
page
HARD/NO START/RESTART (EXCP. HA)
ENGINE STALL
HESITATION/SURGING/FLAT SPOT
SPARK KNOCK/DETONATION
LACK OF POWER/POOR ACCELERATION
HIGH IDLE/LOW IDLE
ROUGH IDLE/HUNTING
IDLING VIBRATION
SLOW/NO RETURN TO IDLE
OVERHEATS/WATER TEMPERATURE HIGH
EXCESSIVE FUEL CONSUMPTION
EXCESSIVE OIL CONSUMPTION
BATTERY DEAD (UNDER CHARGE)
Warranty symptom code AA AB AC AD AE AF AG AH AJ AK AL AM HA
3AA93ABC3ACD3AC03ACA3AC03AC63AC53A913A773A893A873A873A8E3A773A983AC73AC93AC03AC3
3A893A873A873A8F3A773A9D3AAF3A8A3A8C3A863A9D3AAF3A8B3A8C

EC-690
< SERVICE INFORMATION >[VK45DE]
TROUBLE DIAGNOSIS
21
22
23
40
41
42
44
63W
R
P
PU
BR
B
OR
G Fuel injector No. 5
Fuel injector No. 3
Fuel injector No. 1
Fuel injector No. 6
Fuel injector No. 4
Fuel injector No. 2
Fuel injector No. 7
Fuel injector No. 8 [Engine is running]

Warm-up condition
 Idle speed
NOTE:
The pulse cycle changes depending on rpm
at idle BATTERY VOLTAGE
(11 - 14V)
[Engine is running]
 Warm-up condition
 Engine speed: 2,000 rpm BATTERY VOLTAGE
(11 - 14V)
24 P A/F sensor 1 heater
(Bank 2) [Engine is running]

Warm-up condition
 Idle speed Approximately 5V
25 P Heated oxygen sensor 2
heater (Bank 2) [Engine is running]
 Engine speed: Below 3,600 rpm after the fol-
lowing 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 - 1.0V
[Ignition switch: ON]
 Engine stopped
[Engine is running]
 Engine speed: Above 3,600 rpm BATTERY VOLTAGE
(11 - 14V)
29 GY VIAS control solenoid valve [Engine is running]
 Selector lever: P or N
0 - 1.0V
[Engine is running]
 Selector lever: D
 Engine speed: Below 5,000 rpm BATTERY VOLTAGE
(11 - 14V)
[Engine is running]
 Engine speed: Above 5,000 rpm 0 - 1.0V
32 OR EVAP control system pres-
sure sensor
[Ignition switch: ON]
Approximately 1.8 - 4.8V
34 Y Intake air temperature sen-
sor
[Engine is running] Approximately 0 - 4.8V
Output voltage varies with intake
air temperature.
36 W Knock sensor (Bank 2) [Engine is running]
 Idle speed
Approximately 2.5V
TER-
MI-
NAL NO. WIRE
COLOR ITEM CONDITION DATA (DC Voltage)
PBIB0042E
PBIB0043E
PBIB1584E
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EC-692
< SERVICE INFORMATION >[VK45DE]
TROUBLE DIAGNOSIS
51 L/W Mass air flow sensor[Engine is running]

Warm-up condition
 Idle speed 1.0 - 1.3V
[Engine is running]
 Warm-up condition
 Engine speed: 2,500 rpm 1.6 - 2.0V
53 R/L Intake valve timing control
position sensor (Bank 2) [Engine is running]

Warm-up condition
 Idle speed 0 - 1.0V
[Engine is running]
 Engine speed: 2,000 rpm 0 - 1.0V
55 W/R Heated oxygen sensor 2
(Bank 1) [Engine is running]
 Revving engine from idle to 3,000 rpm quick-
ly after the following conditions are met
- Engine: After warming up
- After keeping the engine speed between
3,500 and 4,000 rpm for 1 minute and at idle
for 1 minute under no load 0 - Approximately 1.0V
57 G A/F sensor 1 (Bank 2) [Engine is running]

Warm-up condition
 Idle speed Approximately 2.6V
58 L Approximately 2.3V
76 R Approximately 3.1V
77 OR Approximately 2.3V
66 B Sensor ground
(Throttle position sensor) [Engine is running]

Warm-up condition
 Idle speed Approximately 0V
67 B/W Sensor ground [Engine is running]

Warm-up condition
 Idle speed Approximately 0V
68 SB Sensor power supply
(Power steering pressure
sensor) [Ignition switch: ON]
Approximately 5V
69 R Throttle position sensor 2 [Ignition switch: ON]
 Engine stopped
 Selector lever: D
 Accelerator pedal: Fully released
Less than 4.75V
[Ignition switch: ON]
 Engine stopped
 Selector lever: D
 Accelerator pedal: Fully depressed More than 0.36V
70 L/R Refrigerant pressure sensor [Engine is running]

Warm-up condition
 Both A/C switch and blower fan motor switch: ON (Compressor operates) 1.0 - 4.0V
TER-
MI-
NAL NO. WIRE
COLOR ITEM CONDITION DATA (DC Voltage)
PBIB2046E
3AA93ABC3ACD3AC03ACA3AC03AC63AC53A913A773A893A873A873A8E3A773A983AC73AC93AC03AC3
3A893A873A873A8F3A773A9D3AAF3A8A3A8C3A863A9D3AAF3A8B3A8C

EC-696
< SERVICE INFORMATION >[VK45DE]
TROUBLE DIAGNOSIS
ItemDIAGNOSTIC TEST MODE
WORK
SUPPORT SELF-DIAGNOSTIC
RESULTS DATA
MONI-
TOR ACTIVE
TEST DTC & SRT
CONFIRMATION
DTC*1 FREEZE
FRAME
DATA*2 SRT STA-
TUS DTC
WORK
SUP-
PORT
ENGINE CONTROL COMPONENT PARTS
INPUT
Crankshaft position sensor (POS) ×××
Camshaft position sensor (PHASE) ×××
Mass air flow sensor ××
Engine coolant temperature sensor ××××
Air fuel ratio sensor 1 ××××
Heated oxygen sensor 2 ××××
Wheel sensor ×××
Accelerator pedal position sensor ××
Throttle position sensor ×××
Fuel tank temperature sensor ×××
EVAP control system pressure sen-
sor ××
Intake air temperature sensor ×××
Knock sensor ×
Refrigerant pressure sensor ×
Closed throttle position switch (ac-
celerator pedal position sensor sig-
nal) ×
Air conditioner switch ×
Park/neutral position (PNP) switch ××
St op la mp sw i tc h ××
Power steering pressure sensor ××
Battery voltage ×
Load signal ×
Snow mode switch ×
Intake valve timing control position
sensor ××
Fuel level sensor ××
ICC steering switch ××
ASCD steering switch ××
ICC brake switch ××
ASCD brake switch ××
3AA93ABC3ACD3AC03ACA3AC03AC63AC53A913A773A893A873A873A8E3A773A983AC73AC93AC03AC3
3A893A873A873A8F3A773A9D3AAF3A8A3A8C3A863A9D3AAF3A8B3A8C

TROUBLE DIAGNOSISEC-697
< SERVICE INFORMATION > [VK45DE]
C
D
E
F
G H
I
J
K L
M A
EC
NP
O
X: Applicable
*1: This item includes 1st trip DTCs.
*2: This mode includes 1st trip freeze frame data or freeze fr
ame data. The items appear on CONSULT-III screen in freeze frame data
mode only if a 1st trip DTC or DTC is detected. For details, refer to EC-633
.
*3: Always “CMPLT ” is displayed.
WORK SUPPORT MODE
Work Item
ENGINE CONTROL COMPONENT PARTS
OUTPUT
Fuel injector ××
Power transistor (Ignition timing) ××
Throttle contro l motor relay ××
Throttle control motor ×
EVAP canister purge volume con-
trol solenoid valve ××××
Air conditioner relay ×
Fuel pump relay ×××
Cooling fan relay ×××
Air fuel ratio sensor 1 heater ××
×*
3
Heated oxygen sensor 2 heater ××
×*3
EVAP canister vent control valve ×× ××
Intake valve timing control solenoid
valve ×××
VIAS control solenoid valve ×××
Calculated load value ××
Item
DIAGNOSTIC TEST MODE
WORK
SUPPORT SELF-DIAGNOSTIC
RESULTS DATA
MONI- TOR ACTIVE
TEST DTC & SRT
CONFIRMATION
DTC*1 FREEZE
FRAME
DATA*2 SRT STA-
TUS DTC
WORK SUP-
PORT
WORK ITEM CONDITION USAGE
FUEL PRESSURE RELEASE  FUEL PUMP WILL STOP BY TOUCHING “START” DUR- ING IDLING.
CRANK A FEW TIMES AFTER ENGINE STALLS. When releasing fuel pressure from
fuel line
IDLE AIR VOL LEARN  THE IDLE AIR VOLUME THAT KEEPS THE ENGINE WITHIN THE SPECIFIED RANGE IS MEMORIZED IN
ECM. When learning the idle air volume
SELF-LEARNING CONT  THE COEFFICI ENT OF SELF-LEARNING CONTROL
MIXTURE RATIO RETURNS TO THE ORIGINAL COEF-
FICIENT. When clearing the coefficient of
self-learning control value
3AA93ABC3ACD3AC03ACA3AC03AC63AC53A913A773A893A873A873A8E3A773A983AC73AC93AC03AC3
3A893A873A873A8F3A773A9D3AAF3A8A3A8C3A863A9D3AAF3A8B3A8C

EC-700
< SERVICE INFORMATION >[VK45DE]
TROUBLE DIAGNOSIS
FUEL T/TMP SE
°C or °F  The fuel temperature (determined by the signal
voltage of the fuel tank temperature sensor) is
displayed.
INT/A TEMP SE °C or °F  The intake air temperature (determined by the
signal voltage of the intake air temperature sen-
sor) is indicated.
EVAP SYS PRES V  The signal voltage of EVAP control system pres-
sure sensor is displayed.
FUEL LEVEL SE V  The signal voltage of the fuel level sensor is dis-
played.
START SIGNAL ON/OFF  Indicates start signal status [ON/OFF] computed
by the ECM according to the signals of engine
speed and battery voltage.  After starting the engine, [OFF] is dis-
played regardless of the starter signal.
CLSD THL POS ON/OFF  Indicates idle position [ON/OFF] computed by
ECM according to the accelerator pedal position
sensor signal.
AIR COND SIG ON/OFF  Indicates [ON/OFF] condition of the air condi-
tioner switch as determined by the air condition-
er signal.
P/N POSI SW ON/OFF  Indicates [ON/OFF] condition from the park/neu-
tral position (PNP) switch signal.
PW/ST SIGNAL ON/OFF  [ON/OFF] condition of the power steering sys-
tem (determined by the signal voltage of the
power steering pressure sensor signal) is indi-
cated.
LOAD SIGNAL ON/OFF  Indicates [ON/OFF] condition from the electrical
load signal.
ON: Rear window defogger switch is ON and/or
lighting switch is in 2nd position.
OFF: Both rear window defogger switch and
lighting switch are OFF.
IGNITION SW ON/OFF  Indicates [ON/OFF] condition from ignition
switch signal.
HEATER FAN SW ON/OFF  Indicates [ON/OFF] condition from the heater
fan switch signal.
BRAKE SW ON/OFF  Indicates [ON/OFF] condition from the stop
lamp switch signal.
INJ PULSE-B1 msec  Indicates the actual fuel injection pulse width compensated by ECM according to the input
signals.  When the engine is stopped, a certain
computed value is indicated.
INJ PULSE-B2 msec
IGN TIMING BTDC  Indicates the ignition timing computed by ECM
according to the input signals.  When the engine is stopped, a certain
value is indicated.
CAL/LD VALUE [%] %  “Calculated load value” indicates the value of
the current air flow divided by peak air flow.
MASS AIRFLOW g·m/s  Indicates the mass air flow computed by ECM
according to the signal voltage of the mass air
flow sensor.
PURG VOL C/V %  Indicates the EVAP canister purge volume con-
trol solenoid valve control value computed by
the ECM according to the input signals.
 The opening becomes larger as the value in- creases.
INT/V TIM (B1) °CA
 Indicates [ °CA] of intake camshaft advanced an-
gle.
INT/V TIM (B2) °CA
Monitored item Unit Description Remarks
3AA93ABC3ACD3AC03ACA3AC03AC63AC53A913A773A893A873A873A8E3A773A983AC73AC93AC03AC3
3A893A873A873A8F3A773A9D3AAF3A8A3A8C3A863A9D3AAF3A8B3A8C