2004 INFINITI FX35 air condition

EC-726
[VK45DE]
TROUBLE DIAGNOSIS
Revision: 2004 November 2004 FX35/FX45
TROUBLE DIAGNOSISPFP:00004
Trouble Diagnosis IntroductionABS00BZO
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-II (or GST) or a circuit tester connected should
be performed. Follow the Work Flow on EC-727
.
Before undertaking actual checks, take a few minutes to talk with a
customer who approaches with a driveability 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 Diagnostic Worksheet like the example
on EC-729
should be used.
Start your diagnosis by looking for conventional malfunctions first.
This will help troubleshoot driveability malfunctions on an electroni-
cally controlled engine vehicle.
MEF036D
SEF233G
SEF234G

EC-728
[VK45DE]
TROUBLE DIAGNOSIS
Revision: 2004 November 2004 FX35/FX45
Description for Work Flow
DIAGNOSTIC WORKSHEET
Description
There are many operating conditions that lead to the malfunction of
engine components. A good grasp of such conditions can make trou-
bleshooting faster and more accurate.
In general, each customer feels differently about an incident. It is
important to fully understand the symptoms or conditions for a cus-
tomer complaint.
Utilize a diagnostic worksheet like the one on the next page in order
to organize all the information for troubleshooting.
Some conditions may cause the MIL to come on steady or blink and
DTC to be detected. Examples:

Vehicle ran out of fuel, which caused the engine to misfire.
STEP DESCRIPTION
STEP IGet detailed information about the conditions and the environment when the incident/symptom occurred using the
EC-728, "
DIAGNOSTIC WORKSHEET" .
STEP IIBefore confirming the concern, check and write down (print out using CONSULT-II or GST) the (1st trip) DTC and the
(1st trip) freeze frame data, then erase the DTC and the data. (Refer to EC-715
.) The (1st trip) DTC and the (1st trip)
freeze frame data can be used when duplicating the incident at STEP III & IV.
If the incident cannot be verified, perform EC-784, "
TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT" .
Study the relationship between the cause, specified by (1st trip) DTC, and the symptom described by the customer.
(The Symptom Matrix Chart will be useful. See EC-738, "
Symptom Matrix Chart" .)
Also check related service bulletins for information.
STEP IIITry to confirm the symptom and under what conditions the incident occurs.
The DIAGNOSTIC WORK SHEET and the freeze frame data are useful to verify the incident. Connect CONSULT-II
to the vehicle in“ DATA MONITOR (AUTO TRIG)” mode and check real time diagnosis results.
If the incident cannot be verified, perform EC-784, "
TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT" .
If the malfunction code is detected, skip STEP IV and perform STEP V.
STEP IVTry to detect the (1st trip) DTC by driving in (or performing) the DTC Confirmation Procedure. Check and read the (1st
trip) DTC and (1st trip) freeze frame data by using CONSULT-II or GST.
During the (1st trip) DTC verification, be sure to connect CONSULT-II to the vehicle in “DATA MONITOR (AUTO
TRIG)” mode and check real time diagnosis results.
If the incident cannot be verified, perform EC-784, "
TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT" .
In case the DTC Confirmation Procedure is not available, perform the Overall Function Check instead. The (1st trip)
DTC cannot be displayed by this check, however, this simplified check is an effective alternative.
The NG result of the Overall Function Check is the same as the (1st trip) DTC detection.
STEP VTake the appropriate action based on the results of STEP I through IV.
If the malfunction code is indicated, proceed to TROUBLE DIAGNOSIS FOR DTC PXXXX.
If the normal code is indicated, proceed to the BASIC INSPECTION. (Refer to EC-733
.) Then perform inspections
according to the Symptom Matrix Chart. (Refer to EC-738
.)
STEP VIIdentify where to begin diagnosis based on the relationship study between symptom and possible causes. Inspect the
system for mechanical binding, loose connectors or wiring damage using (tracing) “Harness Layouts”.
Gently shake the related connectors, components or wiring harness with CONSULT-II set in “DATA MONITOR
(AUTO TRIG)” mode.
Check the voltage of the related ECM terminals or monitor the output data from the related sensors with CONSULT-II.
Refer to EC-750
, EC-775 .
The Diagnostic Procedure in EC section contains a description based on open circuit inspection. A short circuit
inspection is also required for the circuit check in the Diagnostic Procedure. For details, refer to “Circuit Inspection” in
GI-27, "
How to Perform Efficient Diagnosis for an Electrical Incident" .
Repair or replace the malfunction parts.
If malfunctioning part cannot be detected, perform EC-784, "
TROUBLE DIAGNOSIS FOR INTERMITTENT INCI-
DENT" .
STEP VIIOnce you have repaired the circuit or replaced a component, you need to run the engine in the same conditions and
circumstances which resulted in the customer's initial complaint.
Perform the DTC Confirmation Procedure and confirm the normal code [DTC No. P0000] is detected. If the incident is
still detected in the final check, perform STEP VI by using a method different from the previous one.
Before returning the vehicle to the customer, be sure to erase the unnecessary (already fixed) (1st trip) DTC in ECM
and TCM (Transmission control module). (Refer to EC-715, "
HOW TO ERASE EMISSION-RELATED DIAGNOSTIC
INFORMATION" and AT- 3 9 , "HOW TO ERASE DTC" .)
SEF907L

TROUBLE DIAGNOSIS
EC-731
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Revision: 2004 November 2004 FX35/FX45
Fail-safe ChartABS00BZQ
When the DTC listed below is detected, the ECM enters fail-safe mode and the MIL lights up.
2
P0031P0032 P0051 P0052 Heated oxygen sensor 1 heater

P0037 P0038 P0057 P0058 Heated oxygen sensor 2 heater

P0132 P0133 P0134 P0152 P0153 P0154 P1143 P1144 P1163 P1164 Heated oxygen sensor 1

P0138 P0139 P0158 P0159 P1146 P1147 P1166 P1167 Heated oxygen sensor 2

P0441 EVAP control system purge flow monitoring

P0444 P0445 P1444 EVAP canister purge volume control solenoid valve

P0447 P1446 EVAP canister vent control valve

P0451 P0452 P0453 EVAP control system pressure sensor

P0550 Power steering pressure sensor

P0710 P0720 P0740 P0744 P0745 P1716 P1720 P1730 P1752 P1754 P1757 P1759 P1762 P1764 P1767 P1769
P1772 P1774 A/T related sensors, solenoid valves and switches

P1065 ECM power supply

P 1111 P 1136 Intake valve timing control solenoid valve

P1122 Electric throttle control function

P1124 P1126 P1128 Electric throttle control actuator

P1140 P1145 Intake valve timing control position sensor

P1217 Engine over temperature (OVERHEAT)

P1805 Brake switch
3

P0011 P0021 Intake valve timing control

P0171 P0172 P0174 P0175 Fuel injection system function

P0300 - P0308 Misfire

P0420 P0430 Three way catalyst function

P0442 P0456 EVAP control system (SMALL LEAK, VERY SMALL LEAK)

P0455 EVAP control system (GROSS LEAK)

P0506 P0507 Idle speed control system

P1121 Electric throttle control actuator

P1148 P1168 Closed loop control

P1211 TCS control unit

P1212 TCS communication line

P1564 ICC steering switch/ASCD steering switch

P1568 ICC command value

P1572 ICC brake switch/ASCD brake switch

P1574 ICC vehicle speed sensor/ASCD vehicle speed sensor

P1780 Shift change signal Priority Detected items (DTC)
DTC No. Detected items Engine operating condition in fail-safe mode
P0102
P0103
P1102Mass air flow sensor circuit Engine speed will not rise more than 2,400 rpm due to the fuel cut.

EC-732
[VK45DE]
TROUBLE DIAGNOSIS
Revision: 2004 November 2004 FX35/FX45

When there is an open circuit on MIL circuit, the ECM cannot warn the driver by lighting up MIL when
there is malfunction on engine control system.
Therefore, when electrical controlled throttle and part of ECM related diagnoses are continuously detected
as NG for 5 trips, ECM warns the driver that engine control system malfunctions and MIL circuit is open by
means of operating fail-safe function.
The fail-safe function also operates when above diagnoses except MIL circuit are detected and demands
the driver to repair the malfunction.
P0117
P0118Engine coolant tempera-
ture sensor circuitEngine coolant temperature will be determined by ECM based on the time after turning
ignition switch ON or START.
CONSULT-II displays the engine coolant temperature decided by ECM.
ConditionEngine coolant temperature decided
(CONSULT-II display)
Just as ignition switch is turned
ON or START40°C (104°F)
More than approx. 4 minutes after
ignition ON or START80°C (176°F)
Except as shown above40 - 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
P2135Throttle 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.
P1121 Electric throttle control
actuator(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.
P1122 Electric throttle control
functionECM stops the electric throttle control actuator control, throttle valve is maintained at a
fixed opening (approx. 5 degrees) by the return spring.
P1124
P1126Throttle 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.
P1128 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.
P1229 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.
P2122
P2123
P2127
P2128
P2138Accelerator pedal position
sensorThe 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. DTC No. Detected items Engine operating condition in fail-safe mode
Engine operating condition in fail-safe mode Engine speed will not rise more than 2,500 rpm due to the fuel cut

TROUBLE DIAGNOSIS
EC-733
[VK45DE]
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Revision: 2004 November 2004 FX35/FX45
Basic InspectionABS00BZR
1. INSPECTION START
1. Check service records for any recent repairs that may indicate a related malfunction, or a current need for
scheduled maintenance.
2. Open engine hood and check the following:
–Harness connectors for improper connections
–Wiring harness for improper connections, pinches and cut
–Vacuum hoses for splits, kinks and improper connections
–Hoses and ducts for leaks
–Air cleaner clogging
–Gasket
3. Confirm that electrical or mechanical loads are not applied.
–Head lamp switch is OFF.
–Air conditioner switch is OFF.
–Rear window defogger switch is OFF.
–Steering wheel is in the straight-ahead position, etc.
4. Start engine and warm it up until engine coolant temperature
indicator points the middle of gauge.
Ensure engine stays below 1,000 rpm.
5. Run engine at about 2,000 rpm for about 2 minutes under no
load.
6. Make sure that no DTC is displayed with CONSULT-II or GST.
OK or NG
OK >> GO TO 3.
NG >> GO TO 2.
2. REPAIR OR REPLACE
Repair or replace components as necessary according to corresponding Diagnostic Procedure.
>> GO TO 3.
SEF983U
SEF976U
SEF977U

TROUBLE DIAGNOSIS
EC-739
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Revision: 2004 November 2004 FX35/FX45
1 - 6: The numbers refer to the order of inspection.
(continued on next page)Power steering pressure sensor circuit 2 3 3EC-1052
ECM 22333333333EC-1057,
EC-1060
Intake valve timing control solenoid valve cir-
cuit32 13223 3EC-1070
PNP switch circuit 3 3 3 3 3EC-1211
Refrigerant pressure sensor circuit 2 3 3 4EC-1287
Electrical load signal circuit 3EC-1292
Air conditioner circuit223333333 3 2AT C - 4 0
VIAS control solenoid valve circuit 1EC-1254
ABS actuator and electric unit (control unit) 4EC-1140
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

EC-754
[VK45DE]
TROUBLE DIAGNOSIS
Revision: 2004 November 2004 FX35/FX45
21
22
23
40
41
42
44
63W
R
P
PU
BR
B
OR
GInjector No. 5
Injector No. 3
Injector No. 1
Injector No. 6
Injector No. 4
Injector No. 2
Injector No. 7
Injector No. 8[Engine is running]

Warm-up condition

Idle speed
NOTE:
The pulse cycle changes depending on rpm
at idleBATTERY VOLTAGE
(11 - 14V)
[Engine is running]

Warm-up condition

Engine speed is 2,000 rpmBATTERY VOLTAGE
(11 - 14V)
24 BRHeated oxygen sensor 1
heater (bank 2)[Engine is running]

Warm-up condition

Engine speed is below 3,000 rpmApproximately 7V
[Engine is running]

Engine speed is above 3,000 rpmBATTERY VOLTAGE
(11 - 14V)
25 PHeated oxygen sensor 2
heater (bank 2)[Engine is running]

Engine speed is 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 load0 - 1.0V
[Ignition switch: ON]

Engine stopped
[Engine is running]

Engine speed is above 3,600 rpmBATTERY VOLTAGE
(11 - 14V)
29 GY VIAS control solenoid valve[Engine is running]

Shift lever position is P or N0 - 1.0V
[Engine is running]

Shift lever position is DBATTERY VOLTAGE
(11 - 14V)
[Engine is running]

Engine speed is above 5,000 rpm0 - 1.0V
32 OREVAP control system pres-
sure sensor[Ignition switch: ON]Approximately 1.8 - 4.8V
34 YIntake air temperature sen-
sor[Engine is running]Approximately 0 - 4.8V
Output voltage varies with intake
air temperature. TER-
MINAL
NO.WIRE
COLORITEM CONDITION DATA (DC Voltage)
PBIB0042E
PBIB0043E
PBIB0519E

TROUBLE DIAGNOSIS
EC-755
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Revision: 2004 November 2004 FX35/FX4535 BRHeated oxygen sensor 1
(bank 2)[Engine is running]
Warm-up condition

Engine speed is 2,000 rpm0 - Approximately 1.0V
(Periodically change)
36 W Knock sensor 2[Engine is running]

Idle speedApproximately 2.5V
45 WEVAP canister purge vol-
ume control solenoid valve[Engine is running]

Idle speedBATTERY VOLTAGE
(11 - 14V)
[Engine is running]

Engine speed is about 2,000 rpm (More
than 100 seconds after starting engine)11 - 1 4 V
46
60
61
62
65
79
80
81L
SB
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LG
GY
GIgnition signal No. 7
Ignition signal No. 5
Ignition signal No. 3
Ignition signal No. 1
Ignition signal No. 8
Ignition signal No. 6
Ignition signal No. 4
Ignition signal No. 2[Engine is running]

Warm-up condition

Idle speed
NOTE:
The pulse cycle changes depending on rpm
at idle0 - 0.2V
[Engine is running]

Warm-up condition

Engine speed is 2,000 rpm0.1 - 0.4V
47 LSensor power supply
(Throttle position sensor)[Ignition switch: ON]Approximately 5V
48 LSensor power supply
(Mass air flow sensor /
EVAP control system pres-
sure sensor)[Ignition switch: ON]Approximately 5V
49 PUSensor power supply
(Refrigerant pressure sen-
sor)[Ignition switch: ON]Approximately 5V TER-
MINAL
NO.WIRE
COLORITEM CONDITION DATA (DC Voltage)
PBIB0050E
PBIB0051E
PBIB0044E
PBIB0045E