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
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TROUBLE DIAGNOSISEC-671
< SERVICE INFORMATION > [VK45DE]
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Fail-Safe ChartINFOID:0000000001326525
When the DTC listed below is detected, the EC
M enters fail-safe mode and the MIL lights up.
Priority Detected items (DTC)
1 U1000 U1001 CAN communication line U1010 CAN communication
P0101 P0102 P0103 Mass air flow sensor
P0112 P0113 P0127 Intake air temperature sensor
P0117 P0118 P0125 Engine coolant temperature sensor
P0122 P0123 P0222 P0223 P1225 P1226 P2135 Throttle position sensor
P0128 Thermostat function
P0181 P0182 P0183 Fuel tank temperature sensor
P0327 P0328 P0332 P0333 Knock sensor
P0335 Crankshaft position sensor (POS)
P0340 Camshaft posi tion sensor (PHASE)
P0460 P0461 P0462 P0463 Fuel level sensor
P0500 Vehicle speed sensor
P0605 ECM
P0643 Sensor power supply
P0700 TCM
P0705 Park/neutral position (PNP) switch
P0850 Park/neutral position (PNP) switch
P1610 - P1615 NATS
P2122 P2123 P2127 P2128 P2138 Accelerator pedal position sensor
2 P0031 P0032 P0051 P0052 Air fuel ratio (A/F) sensor 1 heater P0037 P0038 P0057 P0058 Heated oxygen sensor 2 heater
P0075 P0081 Intake valve timing control solenoid valve
P0130 P0131 P0132 P0133 P0150 P0151 P0152 P0153 P2A00 P2A03 Air fuel ratio (A/F) sensor 1
P0137 P0138 P0139 P0157 P0158 P0159 Heated oxygen sensor 2
P0441 EVAP control system purge flow monitoring
P0443 P0444 P0445 EVAP canister purge volume control solenoid valve
P0447 P0448 EVAP canister vent control valve
P0451 P0452 P0453 EVAP control system pressure sensor
P0550 Power steering pressure sensor
P0603 ECM power supply
P0710 P0717 P0720 P0731 P0732 P0733 P0734 P0735 P0740 P0744 P0745 P1730 P1752 P1757 P1762 P1767
P1772 P1774 A/T related sensors, solenoid valves and switches
P1140 P1145 Intake valve timing control position sensor
P1217 Engine over temperature (OVERHEAT)
P1805 Brake switch
P2100 P2103 Throttle control motor relay
P2101 Electric throttle control function
P2118 Throttle control motor
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 co ntrol system (SMALL LEAK, VERY SMALL LEAK)
P0455 EVAP control system (GROSS LEAK)
P0506 P0507 Idle speed control system
P1148 P1168 Closed loop control
P1211 TCS control unit
P1212 TCS communication line
P1421 Cold start control
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
P1715 Turbine revolution sensor
P1800 VIAS control solenoid valve
P2119 Electric throttle control actuator
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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
TROUBLE DIAGNOSISEC-673
< SERVICE INFORMATION > [VK45DE]
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Symptom Matrix ChartINFOID:0000000001326526
SYSTEM — BASIC ENGINE CONTROL SYSTEM
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
Fuel Fuel pump circuit 11232 22 3 2 EC-1155
Fuel pressure regulator system 334444444 4EC-665
Fuel injector circuit 11232 22 2EM-190
Evaporative emission system 334444444 4EC-618
Air Positive crankcase ventilation sys-
tem 334444444 41
EC-629
Incorrect idle speed adjustment 1 1 1 1 1 EC-658
Electric throttle control actuator 112332222 2 2EC-1092,
EC-1102
IgnitionIncorrect ignition timing adjustment33111 11 1 EC-658
Ignition circuit 11222 22 2EC-1166
Main power supply and ground circuit 22333 33 23 EC-718
Mass air flow sensor circuit
1
12 2
222 2 EC-761,
EC-768
,
Engine coolant temperature sensor circuit
333
EC-779
,
EC-790
A/F sensor 1 circuit EC-798
,
EC-806
,
EC-814
,
EC-822
,
EC-1129
Throttle position sensor circuit
22EC-784
,
EC-889
,
EC-1041
,
EC-1043
,
E C - 111 6
Accelerator pedal position sensor circuit 3 2 1 EC-1009
,
EC-1104
,
E C - 111 0
,
EC-1122
Knock sensor circuit 2 3 EC-902
Crankshaft position sensor (POS) circuit 2 2EC-906
Camshaft position sensor (PHASE) circuit 3 2EC-911
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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
TROUBLE DIAGNOSISEC-675
< SERVICE INFORMATION > [VK45DE]
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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
Fuel Fuel tank 5
5 FL-10
Fuel piping 5 5 5 5 5 5
EM-190
Va p o r l o c k —
Valve deposit 5 555 55 5 —
Poor fuel (Heavy weight gasoline,
Low octane) —
Air Air duct
55555 5 EM-173
Air cleaner
EM-173
Air leakage from air duct
(Mass air flow sensor — electric
throttle control actuator)
5555 EM-173
Electric throttle control actuator
EM-175
Air leakage from intake manifold/
Collector/GasketEM-175
Cranking Battery
111111
11
SC-4
Generator circuit
SC-19
Starter circuit 3SC-8
Signal plate 6EM-241
PNP switch 4AT- 1 0 2
Engine Cylinder head
55555 55 5 EM-226
Cylinder head gasket 4 3
Cylinder block
66666 66 6 4
EM-241
Piston
Piston ring
Connecting rod
Bearing
Crankshaft
Va l v e
mecha-
nism Timing chain
55555 55 5 EM-199
Camshaft
EM-211
Intake valve timing controlEM-199
Intake valve
3EM-199
Exhaust valve
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EC-676
< SERVICE INFORMATION >[VK45DE]
TROUBLE DIAGNOSIS
1 - 6: The numbers refer to the order of inspection.Exhaust Exhaust manifold/Tube/Muffler/
Gasket 55555 55 5 EM-179
,
EX-3
Three way catalyst
Lubrica-
tion Oil pan/Oil strainer/Oil pump/Oil
filter/Oil gallery/Oil cooler
55555 55 5 EM-183
,
LU-29
, LU-
26, LU-27
Oil level (Low)/Filthy oil LU-23
Cooling
Radiator/Hose/Radiator filler cap
55555 55 45 CO-40,
CO-44
Thermostat 5 CO-52
Water pumpCO-50
Water galleryCO-36
Cooling fan
5CO-48
Coolant level (Low)/Contaminat-
ed coolant
CO-37
IVIS (INFINITI Vehicle Immobilizer System —
NATS)11 EC-631 or
BL-185
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
TROUBLE DIAGNOSISEC-691
< SERVICE INFORMATION > [VK45DE]
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45 W
EVAP canister purge volume
control solenoid valve [Engine is running]
Idle speed
BATTERY VOLTAGE
(11 - 14V)
[Engine is running]
Engine speed: About 2,000 rpm (More than 100 seconds after starting engine) 11 - 1 4 V
46
60
61
62
65
79
80
81 BR
SB
L
Y
P
LG
GY
G Ignition 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 idle 0 - 0.2V
[Engine is running]
Warm-up condition
Engine speed: 2,000 rpm 0.1 - 0.4V
47 L Sensor power supply (Throt-
tle position sensor) [Ignition switch: ON]
Approximately 5V
48 L Sensor power supply
(EVAP control system pres-
sure sensor) [Ignition switch: ON]
Approximately 5V
49 PU Sensor power supply
(Refrigerant pressure sen-
sor) [Ignition switch: ON]
Approximately 5V
50 W Throttle position sensor 1 [Ignition switch: ON]
Engine stopped
Selector lever: D
Accelerator pedal: Fully released
More than 0.36V
[Ignition switch: ON]
Engine stopped
Selector lever: D
Accelerator pedal: Fully depressed Less than 4.75V
TER-
MI-
NAL NO. WIRE
COLOR ITEM CONDITION DATA (DC Voltage)PBIB0050E
PBIB0051E
PBIB0044E
PBIB0045E
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