2004 INFINITI FX35 electrical

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
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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
[VK45DE]
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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-772
[VK45DE]
TROUBLE DIAGNOSIS
Revision: 2004 November 2004 FX35/FX45
Operation
1. “AUTO TRIG”

While trying to detect the DTC/1st trip DTC by performing the “DTC Confirmation Procedure”, be sure
to select to “DATA MONITOR (AUTO TRIG)” mode. You can confirm the malfunction at the moment it is
detected.

While narrowing down the possible causes, CONSULT-II should be set in “DATA MONITOR (AUTO
TRIG)” mode, especially in case the incident is intermittent.
When you are inspecting the circuit by gently shaking (or twisting) the suspicious connectors, compo-
nents and harness in the “DTC Confirmation Procedure”, the moment a malfunction is found the DTC/
1st trip DTC will be displayed. (Refer to “INCIDENT SIMULATION TESTS” in GI-27, "
How to Perform
Efficient Diagnosis for an Electrical Incident" .)
2. “MANU TRIG”

If the malfunction is displayed as soon as “DATA MONITOR” is selected, reset CONSULT-II to “MANU
TRIG”. By selecting “MANU TRIG” you can monitor and store the data. The data can be utilized for fur-
ther diagnosis, such as a comparison with the value for the normal operating condition.
Generic Scan Tool (GST) FunctionABS00BZY
DESCRIPTION
Generic Scan Tool (OBDII scan tool) complying with SAE J1978 has
8 different functions explained below.
ISO9141 is used as the protocol.
The name “GST” or “Generic Scan Tool” is used in this service man-
ual.
PBIB0197E
SEF139P

EC-780
[VK45DE]
TROUBLE DIAGNOSIS - SPECIFICATION VALUE
Revision: 2004 November 2004 FX35/FX45
TROUBLE DIAGNOSIS - SPECIFICATION VALUEPFP:00031
DescriptionABS00C01
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 cor-
rection)

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 ConditionABS00C02

Vehicle driven distance: More than 5,000 km (3,017 miles)

Barometric pressure: 98.3 - 104.3 kPa (1.003 - 1.064 kg/cm2 , 14.25 - 15.12 psi)

Atmospheric temperature: 20 - 30°C (68 - 86°F)

Engine coolant temperature: 75 - 95°C (167 - 203°F)

Transmission: Warmed-up*1

Electrical load: Not applied*2

Engine speed: Idle
*1: After the engine is warmed up to normal operating temperature, drive vehicle until “FLUID TEMP SE” (A/T
fluid temperature sensor signal) indicates more than 60°C (140°F).
*2: Rear window defogger switch, air conditioner switch, lighting switch are OFF. Steering wheel is straight
ahead.
Inspection ProcedureABS00C03
NOTE:
Perform “DATA MONITOR (SPEC)” mode in maximum scale display.
1. Perform EC-733, "
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-781, "
Diagnostic Procedure" .
SEF601Z

EC-784
[VK45DE]
TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT
Revision: 2004 November 2004 FX35/FX45
TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENTPFP:00006
DescriptionABS00C05
Intermittent incidents (I/I) 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 I/I occur-
rences 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 I/I Report Situations
Diagnostic ProcedureABS00C06
1. INSPECTION START
Erase (1st trip) DTCs. Refer to EC-715, "
HOW TO ERASE EMISSION-RELATED DIAGNOSTIC INFORMA-
TION" .
>> GO TO 2.
2. CHECK GROUND TERMINALS
Check ground terminals for corroding or loose connection.
Refer to GI-27, "
How to Perform Efficient Diagnosis for an Electrical Incident" , "CIRCUIT INSPECTION",
"Ground Inspection".
OK or NG
OK >> GO TO 3.
NG >> Repair or replace.
3. SEARCH FOR ELECTRICAL INCIDENT
Perform GI-27, "
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-24, "
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
II The CONSULT-II is used. The SELF-DIAG RESULTS screen shows time data other than [0] or [1t].
III The symptom described by the customer does not recur.
IV (1st trip) DTC does not appear during the DTC Confirmation Procedure.
VI The Diagnostic Procedure for PXXXX does not indicate the malfunctioning area.

POWER SUPPLY AND GROUND CIRCUIT
EC-791
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Revision: 2004 November 2004 FX35/FX45
Ground Inspection ABS00C09
Ground connections are very important to the proper operation of electrical and electronic circuits. Ground
connections are often exposed to moisture, dirt and other corrosive elements. The corrosion (rust) can
become an unwanted resistance. This unwanted resistance can change the way a circuit works.
Electronically controlled circuits are very sensitive to proper grounding. A loose or corroded ground can drasti-
cally affect an electronically controlled circuit. A poor or corroded ground can easily affect the circuit. Even
when the ground connection looks clean, there can be a thin film of rust on the surface.
When inspecting a ground connection follow these rules:

Remove the ground bolt or screw.

Inspect all mating surfaces for tarnish, dirt, rust, etc.

Clean as required to assure good contact.

Reinstall bolt or screw securely.

Inspect for “add-on” accessories which may be interfering with the ground circuit.

If several wires are crimped into one ground eyelet terminal, check for proper crimps. Make sure all of the
wires are clean, securely fastened and providing a good ground path. If multiple wires are cased in one
eyelet make sure no ground wires have excess wire insulation.
For detailed ground distribution information, refer to PG-31, "
Ground Distribution" .
PBIB1870E

DTC P0112, P0113 IAT SENSOR
EC-837
[VK45DE]
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Revision: 2004 November 2004 FX35/FX45
DTC P0112, P0113 IAT SENSORPFP:22630
Component DescriptionABS00C1K
The intake air temperature sensor is built-into mass air flow sensor.
The sensor detects intake air temperature and transmits a signal to
the ECM.
The temperature sensing unit uses a thermistor which is sensitive to
the change in temperature. Electrical resistance of the thermistor
decreases in response to the temperature rise.

*: These data are reference values and are measured between ECM terminal 34
(Intake air temperature sensor) and ground.
CAUTION:
Do not use ECM ground terminals when measuring input/output
voltage. Doing so may result in damage to the ECM's transistor. Use a ground other than ECM termi-
nals, such as the ground.
On Board Diagnosis LogicABS00C1L
DTC Confirmation ProcedureABS00C1M
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.
WITH CONSULT-II
1. Turn ignition switch ON.
2. Select “DATA MONITOR” mode with CONSULT-II.
3. Wait at least 5 seconds.
4. If 1st trip DTC is detected, go to EC-840, "
Diagnostic Procedure"
.
SEC266C
Intake air temperature
°C (°F)Voltage* V Resistance kΩ
-10 (14) 4.43 7.9 - 9.3
25 (77) 3.32 1.9 - 2.1
80 (176) 1.23 0.31 - 0.37
SEF012P
DTC No.Trouble diagnosis
nameDTC detecting condition Possible cause
P0112
0112Intake air tempera-
ture sensor circuit
low inputAn excessively low voltage from the sensor is
sent to ECM.

Harness or connectors
(The sensor circuit is open or shorted.)

Intake air temperature sensor
P0113
0113Intake air tempera-
ture sensor circuit
high inputAn excessively high voltage from the sensor is
sent to ECM.
SEF058Y