2003 NISSAN TEANA check 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

TROUBLE DIAGNOSIS
EC-421
[VQ]
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51 W Mass air flow sensor[Ignition switch: ON]Approximately 0.4V
[Engine is running]

Warm-up condition

Idle speed0.9 - 1.1V (VQ23DE engine)
1.0 - 1.3V (VQ35DE engine)
[Engine is running]

Warm-up condition

Engine is revving from idle to about 4,000
rpm0.9 - 1.1 to Approx. 2.4
(VQ23DE engine)
1.0 - 1.3 to Approx. 2.4
(VQ35DE engine)
(Check for linear voltage rise in
response to engine being
increased to about 4,000 rpm.)
55 WHeated oxygen sensor 2
(Bank 2)[Engine is running]

Revving engine from idle up to 3,000 rpm
quickly 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 - Approximately 1.0V
60
61
62P/W
L/R
Y/RIgnition signal No. 5
Ignition signal No. 3
Ignition signal No. 1[Engine is running]

Warm-up condition

Idle speed
NOTE:
The pulse cycle changes depending on rpm
at idle0 - 0.3V
[Engine is running]

Warm-up condition

Engine speed: 2,500 rpm0.1 - 0.6V
66 LSensor ground
(Throttle position sensor)[Engine is running]

Warm-up condition

Idle speedApproximately 0V
67 Y Sensor ground[Engine is running]

Warm-up condition

Idle speedApproximately 0V
68 LSensor power supply
(PSP sensor)[Ignition switch: ON]Approximately 5V
69 G Throttle position sensor 2[Ignition switch: ON]

Engine: Stopped

Shift lever: D

Accelerator pedal: Fully releasedLess than 4.75V
[Ignition switch: ON]

Engine: Stopped

Shift lever: D

Accelerator pedal: Fully depressedMore than 0.36V TER-
MINAL
NO.WIRE
COLORITEM CONDITION DATA (DC Voltage)
SEC986C
SEC987C

EC-432
[VQ]
TROUBLE DIAGNOSIS

DATA MONITOR (SPEC) MODE
Monitored Item
NOTE:
Any monitored item that does not match the vehicle being diagnosed is deleted from the display automatically.
ACTIVE TEST MODE
Test Item
Monitored item [Unit]ECM
INPUT
SIG-
NALSMAIN
SIG-
NALSDescription Remarks
ENG SPEED [rpm]××

Indicates the engine speed computed
from the signal of the crankshaft position
sensor (POS) and camshaft position
sensor (PHASE).
MAS A/F SE-B1 [V]××

The signal voltage of the mass air flow
sensor specification is displayed.
When engine is running specification
range is indicated.
B/FUEL SCHDL
[msec]×

Base fuel schedule indicates the fuel
injection pulse width programmed into
ECM, prior to any learned on board cor-
rection.

When engine is running specification
range is indicated.
A/F ALPHA-B1 [%]
A/F ALPHA-B2 [%]×

The mean value of the air-fuel ratio feed-
back correction factor per cycle is indi-
cated.
When engine is running specification
range is indicated.

This data also includes the data for the
air-fuel ratio learning control.
TEST ITEM CONDITION JUDGEMENT CHECK ITEM (REMEDY)
FUEL INJEC-
TION

Engine: Return to the original
trouble condition

Change the amount of fuel injec-
tion using CONSULT-II.If trouble symptom disappears, see
CHECK ITEM.

Harness and connectors

Fuel injector

Heated oxygen sensor 1
IGNITION TIM-
ING

Engine: Return to the original
trouble condition

Timing light: Set

Retard the ignition timing using
CONSULT-II.If trouble symptom disappears, see
CHECK ITEM.

Perform Idle Air Volume Learning.
POWER BAL-
ANCE

Engine: After warming up, idle
the engine.

A/C switch: OFF

Shift lever: P or N

Cut off each fuel injector signal
one at a time using CONSULT-II.Engine runs rough or dies.

Harness and connectors

Compression

Fuel injector

Power transistor

Spark plug

Ignition coil
COOLING FAN*

Ignition switch: ON

Turn the cooling fan “HI”, “MID”,
“LOW” and “OFF” using CON-
SULT-II.Cooling fan moves and stops.
Harness and connectors

Cooling fan motor

IPDM E/R
ENG COOLANT
TEMP

Engine: Return to the original
trouble condition

Change the engine coolant tem-
perature using CONSULT-II.If trouble symptom disappears, see
CHECK ITEM.

Harness and connectors

Engine coolant temperature sen-
sor

Fuel injector
FUEL PUMP
RELAY

Ignition switch: ON (Engine
stopped)

Turn the fuel pump relay “ON”
and “OFF” using CONSULT-II
and listen to operating sound.Fuel pump relay makes the operat-
ing sound.
Harness and connectors

Fuel pump relay

TROUBLE DIAGNOSIS
EC-433
[VQ]
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*: Leaving cooling fan OFF with CONSULT-II while engine is running may cause the engine to overheat.
REAL TIME DIAGNOSIS IN DATA MONITOR MODE (RECORDING VEHICLE DATA)
Description
CONSULT-II has two kinds of triggers and they can be selected by touching “SETTING” in “DATA MONITOR”
mode.
1. “AUTO TRIG” (Automatic trigger):

The malfunction will be identified on the CONSULT-II screen
in real time.
In other words, DTC/1st trip DTC and malfunction item will be
displayed if the malfunction is detected by ECM.
At the moment a malfunction is detected by ECM, “MONI-
TOR” in “DATA MONITOR” screen is changed to “Recording
Data ... xx%” as shown in the figure, and the data after the
malfunction detection is recorded. Then when the percentage
reached 100%, “REAL-TIME DIAG” screen is displayed. If
“STOP” is touched on the screen during “Recording Data ...
xx%”, “REAL-TIME DIAG” screen is also displayed.
The recording time after the malfunction detection and the
recording speed can be changed by “TRIGGER POINT” and
“Recording Speed”. Refer to CONSULT-II Operation Manual.
2. “MANU TRIG” (Manual trigger):

DTC/1st trip DTC and malfunction item will not be displayed
automatically on CONSULT-II screen even though a malfunc-
tion is detected by ECM.
DATA MONITOR can be performed continuously even though
a malfunction is detected.
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.
VIAS SOL VALVE

Ignition switch: ON

Turn solenoid valve “ON” and
“OFF” using CONSULT-II and lis-
ten to operating sound.Solenoid valve makes the operating
sound.
Harness and connectors

Solenoid valve
ENGINE
MOUNTING

Ignition switch: ON

Turn electronic controlled engine
mount “IDLE” and “TRVL” with
the CONSULT-II.Electronic controlled engine mount
makes the operating sound.
Harness and connectors

Electronic controlled engine
mount
PURG VOL
CONT/V

Engine: After warming up, run
engine at 1,500 rpm.

Change the EVAP canister purge
volume control solenoid valve
opening percent using CON-
SULT-II.Engine speed changes according to
the opening percent.
Harness and connectors

Solenoid valve
V/T ASSIGN
ANGLE

Engine: Return to the original
trouble condition

Change intake valve timing using
CONSULT-II.If trouble symptom disappears, see
CHECK ITEM.

Harness and connectors

Intake valve timing control sole-
noid valve TEST ITEM CONDITION JUDGEMENT CHECK ITEM (REMEDY)
PBIB1593E
SEF707X

TROUBLE DIAGNOSIS - SPECIFICATION VALUE
EC-443
[VQ]
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DETAILED PROCEDURE
1. CHECK “A/F ALPHA-B1”, “A/F ALPHA-B2”
1. Start engine.
2. Confirm that the testing conditions are met. Refer to EC-440, "
Testing Condition" .
3. Select “A/F ALPHA-B1”, “A/F ALPHA-B2” in “DATA MONITOR
(SPEC)” mode, and make sure that the each indication is within
the SP value.
NOTE:
Check “A/F ALPHA-B1”, “A/F ALPHA-B2” for approximately 1
minute because they may fluctuate. It is NG if the indication is
out of the SP value even a little.
OK or NG
OK >> GO TO 17.
NG (Less than the SP value)>>GO TO 2.
NG (More than the SP value)>>GO TO 3.
2. CHECK “B/FUEL SCHDL”
Select “B/FUEL SCHDL” in “DATA MONITOR (SPEC)” mode, and
make sure that the indication is within the SP value.
OK or NG
OK >> GO TO 4.
NG (More than the SP value)>>GO TO 19.
3. CHECK “B/FUEL SCHDL”
Select “B/FUEL SCHDL” in “DATA MONITOR (SPEC)” mode, and
make sure that the indication is within the SP value.
OK or NG
OK >> GO TO 6.
NG (More than the SP value)>>GO TO 6.
NG (Less than the SP value)>>GO TO 25.
4. CHECK “A/F ALPHA-B1”, “A/F ALPHA-B2”
1. Stop the engine.
2. Disconnect PCV hose, and then plug it.
3. Start engine.
4. Select “A/F ALPHA-B1”, “A/F ALPHA-B2” in “DATA MONITOR (SPEC)” mode, and make sure that the
each indication is within the SP value.
OK or NG
OK >> GO TO 5.
NG >> GO TO 6.
PBIB2369E
PBIB2332E
PBIB2332E

EC-444
[VQ]
TROUBLE DIAGNOSIS - SPECIFICATION VALUE

5. CHANGE ENGINE OIL
1. Stop the engine.
2. Change engine oil.
NOTE:
This symptom may occur when a large amount of gasoline is mixed with engine oil because of driving
conditions (such as when engine oil temperature does not rise enough since a journey distance is too
short during winter). The symptom will not be detected after changing engine oil or changing driving con-
dition.
>>INSPECTION END
6. CHECK FUEL PRESSURE
Check fuel pressure. (Refer to EC-392, "
FUEL PRESSURE CHECK" .)
OK or NG
OK >> GO TO 9.
NG (Fuel pressure is too high)>>Replace fuel pressure regulator, refer to EC-392, "
FUEL PRESSURE
CHECK" . GO TO 8.
NG (Fuel pressure is too low)>>GO TO 7.
7. DETECT MALFUNCTIONING PART
1. Check the following.
–Clogged and bent fuel hose and fuel tube
–Clogged fuel filter
–Fuel pump and its circuit (Refer to EC-690, "FUEL PUMP" .)
2. If NG, repair or replace the malfunctioning part. (Refer to EC-392, "
FUEL PRESSURE CHECK" .)
If OK, replace fuel pressure regulator.
>> GO TO 8.
8. CHECK “A/F ALPHA-B1”, “A/F ALPHA-B2”
1. Start engine.
2. Select “A/F ALPHA-B1”, “A/F ALPHA-B2” in “DATA MONITOR (SPEC)” mode, and make sure that the
each indication is within the SP value.
OK or NG
OK >>INSPECTION END
NG >> GO TO 9.
9. PERFORM POWER BALANCE TEST
1. Perform “POWER BALANCE” in “ACTIVE TEST” mode.
2. Make sure that the each cylinder produces a momentary engine
speed drop.
OK or NG
OK >> GO TO 12.
NG >> GO TO 10.
PBIB0133E

TROUBLE DIAGNOSIS - SPECIFICATION VALUE
EC-445
[VQ]
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10. DETECT MALFUNCTIONING PART
1. Check the following.
–Ignition coil and its circuit (Refer to EC-735, "IGNITION SIGNAL" .)
–Fuel injector and its circuit (Refer to EC-684, "FUEL INJECTOR" .)
–Intake air leakage
–Low compression pressure (Refer to EM-210, "CHECKING COMPRESSION PRESSURE" .)
2. If NG, repair or replace the malfunctioning part.
If OK, replace fuel injector. (It may be caused by leakage from fuel injector or clogging.)
>> GO TO 11.
11 . CHECK “A/F ALPHA-B1”, “A/F ALPHA-B2”
1. Start engine.
2. Select “A/F ALPHA-B1”, “A/F ALPHA-B2” in “DATA MONITOR (SPEC)” mode, and make sure that the
each indication is within the SP value.
OK or NG
OK >>INSPECTION END
NG >> GO TO 12.
12. CHECK HEATED OXYGEN SENSOR 1 FUNCTION
1. Run engine at about 2,000 rpm for about 2 minutes under no load.
2. Select “HO2S1 MNTR (B1)”, “HO2S1 MNTR (B2)” in “DATA
MONITOR” mode.
3. Running engine at 2,000 rpm under no load (The engine is
warmed up to normal operating temperature.), check that the
monitor fluctuates between LEAN and RICH more than 5 times
during 10 seconds.
OK or NG
OK >> GO TO 15.
NG >> GO TO 13.
13. CHECK HEATED OXYGEN SENSOR 1 CIRCUIT
Check heated oxygen sensor 1 and its circuit. Refer to EC-496
.
>> GO TO 14.
14. CHECK “A/F ALPHA-B1”, “A/F ALPHA-B2”
1. Start engine.
2. Select “A/F ALPHA-B1”, “A/F ALPHA-B2” in “DATA MONITOR (SPEC)” mode, and make sure that the
each indication is within the SP value.
OK or NG
OK >>INSPECTION END
NG >> GO TO 15.1 time: RICH → LEAN → RICH
2 time: RICH → LEAN → RICH → LEAN → RICH
PBIB0120E