2003 NISSAN TEANA engine

EC-394
[VQ]
TROUBLE DIAGNOSIS

TROUBLE DIAGNOSISPFP:00004
Trouble Diagnosis IntroductionBBS004Y6
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 a circuit tester connected should be per-
formed. Follow the Work Flow on EC-395, "
WORK FLOW" .
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-399, "
Worksheet Sample" 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-398
[VQ]
TROUBLE DIAGNOSIS

10. DETECT MALFUNCTIONING PART BY DIAGNOSTIC PROCEDURE
Inspect according to Diagnostic Procedure of the system.
NOTE:
The Diagnostic Procedure in EC section described 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-
24, "How to Perform Efficient Diagnosis for an Electrical Incident" .
Is malfunctioning part detected?
Yes >> GO TO 11.
No >> Monitor input data from related sensors or check voltage of related ECM terminals using CON-
SULT-II. Refer to EC-434, "
CONSULT-II Reference Value in Data Monitor Mode" , EC-415, "ECM
Terminals and Reference Value" .
11 . REPAIR OR REPLACE THE MALFUNCTIONING PART
1. Repair or replace the malfunctioning part.
2. Reconnect parts or connectors disconnected during Diagnostic Procedure again after repair and replace-
ment.
3. Check DTC. If DTC is displayed, erase it, refer to EC-376, "
HOW TO ERASE EMISSION-RELATED
DIAGNOSTIC INFORMATION" .
>> GO TO 12.
12. FINAL CHECK
When DTC was detected in step 2, perform DTC Confirmation Procedure or Overall Function Check again,
and then make sure that the malfunction have been repaired securely.
When symptom was described from the customer, refer to confirmed symptom in step 3 or 4, and make sure
that the symptom is not detected.
OK or NG
NG (DTC*1 is detected)>>GO TO 10.
NG (Symptom remains)>>GO TO 6.
OK >> 1. Before returning the vehicle to the customer, make sure to erase unnecessary DTC*
1 in ECM.
(Refer to EC-376, "
HOW TO ERASE EMISSION-RELATED DIAGNOSTIC INFORMATION" .)
2.INSPECTION END
*1: Include 1st trip DTC.
*2: Include 1st trip freeze frame data.
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 a 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.
SEF907L

EC-400
[VQ]
TROUBLE DIAGNOSIS

DTC Inspection Priority ChartBBS004Y7
If some DTCs are displayed at the same time, perform inspections one by one based on the following priority
chart.
NOTE:
If DTC U1000 and/or U1001 is displayed with other DTC, first perform the trouble diagnosis for DTC
U1000, U1001. Refer to EC-458, "
DTC U1000, U1001 CAN COMMUNICATION LINE" .
Priority Detected items (DTC)
1

U1000 U1001 CAN communication line

P0102 P0103 Mass air flow sensor

P0117 P0118 Engine coolant temperature sensor

P0122 P0123 P0222 P0223 P1225 P1226 P2135 Throttle position sensor

P0327 P0328 Knock sensor

P0335 Crankshaft position sensor (POS)

P0340 P0345 Camshaft position sensor (PHASE)

P0605 ECM

P1229 Sensor power supply

P1610 - P1615 NATS

P1700 CVT control system

P1706 Park/Neutral position (PNP) switch

P2122 P2123 P2127 P2128 P2138 Accelerator pedal position sensor
2

P0132 P0134 P0152 P0154 Heated oxygen sensor 1

P0550 Power steering pressure sensor

P1065 ECM power supply

P 1111 P 11 3 6 I n ta k e v a l v e t i m i n g c o n t r o l s o l e n o i d v a l v e

P1122 Electric throttle control function

P1124 P1126 P1128 Electric throttle control actuator

P1217 Engine over temperature (OVERHEAT)

P1720 Vehicle speed sensor

P1805 Brake switch
3

P0011 P0021 Intake valve timing control

P1121 Electric throttle control actuator

P1211 TCS control unit

P1212 TCS communication line

P1564 ASCD steering switch

P1572 ASCD brake switch

P1574 ASCD vehicle speed sensor

P1715 Primary speed sensor

TROUBLE DIAGNOSIS
EC-401
[VQ]
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EC

Fail-Safe ChartBBS004Y8
When the DTC listed below is detected, the ECM enters fail-safe mode and the MI lights up.

When there is an open circuit on MI circuit, the ECM cannot warn the driver by lighting up MI 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 MI circuit is open by
means of operating fail-safe function.
The fail-safe function also operates when above diagnoses except MI circuit are detected and demands
the driver to repair the malfunction.
DTC No. Detected items Engine operating condition in fail-safe mode
P0102
P0103Mass air flow sensor circuit Engine speed will not rise more than 2,400 rpm due to the fuel cut.
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 P or N 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.
P1805 Brake switch ECM controls the electric throttle control actuator by regulating the throttle opening to a
small range.
Therefore, acceleration will be poor.
Vehicle condition Driving condition
When engine is idling Normal
When accelerating Poor acceleration
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.
Engine operating condition in fail-safe mode Engine speed will not rise more than 2,500 rpm due to the fuel cut

EC-402
[VQ]
TROUBLE DIAGNOSIS

Symptom Matrix ChartBBS004Y9
SYSTEM — BASIC ENGINE CONTROL SYSTEM
SYMPTOM
Refer-
ence 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 2EC-690
Fuel pressure regulator system334444444 4EC-392
Fuel injector circuit 11232 22 2EC-684
Evaporative emission system 334444444 4EC-366
Air Positive crankcase ventilation sys-
tem
334444444 41EC-370
Incorrect idle speed adjustment 1 1 1 1 1EC-381
Electric throttle control actuator 112332222 2 2EC-552,
EC-555
IgnitionIncorrect ignition timing adjustment 33111 11 1EC-381
Ignition circuit 11222 22 2EC-735
Main power supply and ground circuit22333 33 23EC-451
Mass air flow sensor circuit
1
122
222 2EC-466
Engine coolant temperature sensor circuit
333EC-474
Heated oxygen sensor 1 circuitEC-486
,
EC-496
,
EC-696
Throttle position sensor circuit
22EC-479
,
EC-505
,
EC-586
,
EC-588
,
EC-645
Accelerator pedal position sensor circuit 3 2 1EC-590
,
EC-631
,
EC-638
,
EC-652
Knock sensor circuit 2 3EC-512
Crankshaft position sensor (POS) circuit 2 2EC-517
Camshaft position sensor (PHASE) circuit 3 2EC-524
Vehicle speed signal circuit 2 3 3 3EC-762
Power steering pressure sensor circuit 2 3 3EC-533
ECM 22333333333EC-538,
EC-541

TROUBLE DIAGNOSIS
EC-403
[VQ]
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EC

1 - 6: The numbers refer to the order of inspection.
(continued on next page)
SYSTEM — ENGINE MECHANICAL & OTHER
Intake valve timing control solenoid valve cir-
cuit32 13223 3EC-545
PNP switch circuit 3 3 3 3 3EC-614
VIAS control solenoid valve circuit 1EC-753
Refrigerant pressure sensor circuit 2 3 3 4EC-748
Electrical load signal circuit 3EC-670
Air conditioner circuit 223333333 3 2AT C - 3 4
ABS actuator and electric unit (control unit) 4BRC-8 or
BRC-44
SYMPTOM
Refer-
ence 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
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
5FL-8
Fuel piping 5 5 5 5 5 5FL-3
Vapor lock—
Valve deposit
5 555 55 5—
Poor fuel (Heavy weight gaso-
line, Low octane)—

EC-404
[VQ]
TROUBLE DIAGNOSIS

Air Air duct
55555 5EM-131
Air cleanerEM-131
Air leakage from air duct
(Mass air flow sensor — electric
throttle control actuator)
5555EM-131
Electric throttle control actuatorEM-133
Air leakage from intake manifold/
Collector/GasketEM-133,
EM-138
Cranking Battery
111111
11SC-4
Generator circuitSC-27
Starter circuit 3EM-228
Signal plate 6EM-228
PNP switch 4AT- 2 3 0,
CVT-62
Engine Cylinder head
55555 55 5EM-210
Cylinder head gasket 4 3
Cylinder block
66666 66 64
EM-228
Piston
Piston ring
Connecting rod
Bearing
Crankshaft
Va l v e
mecha-
nismTiming chain
55555 55 5EM-173
CamshaftEM-192
Intake valve timing controlEM-173
Intake valve
3EM-210
Exhaust valve
Exhaust Exhaust manifold/Tube/Muffler/
Gasket
55555 55 5EM-140
,
EX-2
Three way catalyst
Lubrica-
tionOil pan/Oil strainer/Oil pump/Oil
filter/Oil gallery/Oil cooler
55555 55 5EM-145
,
LU-22
, LU-
23 , LU-25
Oil level (Low)/Filthy oilLU-19
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

TROUBLE DIAGNOSIS
EC-405
[VQ]
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1 - 6: The numbers refer to the order of inspection.Cooling Radiator/Hose/Radiator filler cap
55555 55 45CO-37
Thermostat 5CO-50
Water pumpCO-46
Water galleryCO-32
Cooling fan
5CO-44
Coolant level (Low)/Contami-
nated coolantCO-34
NATS (NISSAN Anti-theft System) 1 1BL-139
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