2003 NISSAN TEANA Power

EC-428
[VQ]
TROUBLE DIAGNOSIS

DATA MONITOR MODE
Monitored Item
×: Applicable
Monitored item
[Unit]ECM
INPUT
SIGNALSMAIN
SIGNALSDescription Remarks
ENG SPEED [rpm]××

Indicates the engine speed computed from
the signal of the crankshaft position sensor
(POS) and camshaft position sensor
(PHASE).
Accuracy becomes poor if engine
speed drops below the idle rpm.

If the signal is interrupted while the
engine is running, an abnormal value
may be indicated.
MAS A/F SE-B1 [V]××

The signal voltage of the mass air flow sen-
sor is displayed.
When the engine is stopped, a cer-
tain value is indicated.
B/FUEL SCHDL
[msec]×

Base fuel schedule indicates the fuel injec-
tion pulse width programmed into ECM,
prior to any learned on board correction.
A/F ALPHA-B1 [%]×

The mean value of the air-fuel ratio feed-
back correction factor per cycle is indi-
cated.
When the engine is stopped, a cer-
tain value is indicated.

This data also includes the data for
the air-fuel ratio learning control. A/F ALPHA-B2 [%]×
COOLAN TEMP/S
[°C] or [°F]××

The engine coolant temperature (deter-
mined by the signal voltage of the engine
coolant temperature sensor) is displayed.

When the engine coolant tempera-
ture sensor is open or short-cir-
cuited, ECM enters fail-safe mode.
The engine coolant temperature
determined by the ECM is displayed.
HO2S1 (B1) [V]××

The signal voltage of the heated oxygen
sensor 1 is displayed.
HO2S1 (B2) [V]×
HO2S2 (B1) [V]×

The signal voltage of the heated oxygen
sensor 2 is displayed.
HO2S2 (B2) [V]×
HO2S1 MNTR (B1)
[RICH/LEAN]××

Display of heated oxygen sensor 1 signal
during air-fuel ratio feedback control:
RICH: means the mixture became “rich”,
and control is being affected toward a
leaner mixture.
LEAN: means the mixture became “lean”,
and control is being affected toward a rich
mixture.
After turning ON the ignition switch,
“RICH” is displayed until air-fuel mix-
ture ratio feedback control begins.

When the air-fuel ratio feedback is
clamped, the value just before the
clamping is displayed continuously. HO2S1 MNTR (B2)
[RICH/LEAN]×
HO2S2 MNTR (B1)
[RICH/LEAN]×

Display of heated oxygen sensor 2 signal:
RICH: means the amount of oxygen after
three way catalyst is relatively small.
LEAN: means the amount of oxygen after
three way catalyst is relatively large.

When the engine is stopped, a cer-
tain value is indicated.
HO2S2 MNTR (B2)
[RICH/LEAN]×
VHCL SPEED SE
[km/h] or [mph]××

The vehicle speed computed from the vehi-
cle speed signal sent from combination
meter is displayed.
BATTERY VOLT
[V]××

The power supply voltage of ECM is dis-
played.
ACCEL SEN 1 [V]××

The accelerator pedal position sensor sig-
nal voltage is displayed.
ACCEL SEN 2 signal is converted by
ECM internally. Thus, it differs from
ECM terminal voltage signal. ACCEL SEN 2 [V]×
THRTL SEN 1 [V]××

The throttle position sensor signal voltage
is displayed.
THRTL SEN 2 signal is converted by
ECM internally. Thus, it differs from
ECM terminal voltage signal. THRTL SEN 2 [V]×
INT/A TEMP SE
[°C] or [°F]××

The intake air temperature (determined by
the signal voltage of the intake air tempera-
ture sensor) is indicated.

TROUBLE DIAGNOSIS
EC-429
[VQ]
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START SIGNAL
[ON/OFF]××
Indicates start signal status [ON/OFF] com-
puted by the ECM according to the signals
of engine speed and battery voltage.
After starting the engine, [OFF] is
displayed regardless of the starter
signal.
CLSD THL POS
[ON/OFF]××

Indicates idle position [ON/OFF] computed
by ECM according to the accelerator pedal
position sensor signal.
AIR COND SIG
[ON/OFF]××

Indicates [ON/OFF] condition of the air
conditioner switch as determined by the air
conditioner signal.
P/N POSI SW
[ON/OFF]××

Indicates [ON/OFF] condition from the
park/neutral position (PNP) switch signal.
PW/ST SIGNAL
[ON/OFF]××

[ON/OFF] condition of the power steering
system (determined by the signal voltage
of the power steering pressure sensor sig-
nal) is indicated.
LOAD SIGNAL
[ON/OFF]××

Indicates [ON/OFF] condition from the
electrical load signal.
ON: Rear window defogger switch is ON
and/or lighting switch is in 2nd position.
OFF: Both rear window defogger switch
and lighting switch are OFF.
IGNITION SW
[ON/OFF]×

Indicates [ON/OFF] condition from ignition
switch signal.
HEATER FAN SW
[ON/OFF]×

Indicates [ON/OFF] condition from heater
fan switch signal.
BRAKE SW
[ON/OFF]×

Indicates [ON/OFF] condition from the stop
lamp switch signal.
INJ PULSE-B1
[msec]×

Indicates the actual fuel injection pulse
width compensated by ECM according to
the input signals.
When the engine is stopped, a cer-
tain computed value is indicated.
INJ PULSE-B2
[msec]
IGN TIMING
[BTDC]×

Indicates the ignition timing computed by
ECM according to the input signals.
When the engine is stopped, a cer-
tain value is indicated.
PURG VOL C/V
[%]

Indicates the EVAP canister purge volume
control solenoid valve control value com-
puted by the ECM according to the input
signals.

The opening becomes larger as the value
increases.
INT/V TIM (B1)
[°CA]

Indicates [°CA] of intake camshaft
advanced angle.
INT/V TIM (B2)
[°CA]
INT/V SOL (B1) [%]

The control condition of the intake valve
timing control solenoid valve (determined
by ECM according to the input signals) is
indicated.

The advance angle becomes larger as the
value increases. INT/V SOL (B2) [%]Monitored item
[Unit]ECM
INPUT
SIGNALSMAIN
SIGNALSDescription Remarks

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

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

EC-446
[VQ]
TROUBLE DIAGNOSIS - SPECIFICATION VALUE

15. DISCONNECT AND RECONNECT ECM HARNESS CONNECTOR
1. Stop the engine.
2. Disconnect ECM harness connector. Check pin terminal and connector for damage, and then reconnect it.
>> GO TO 16.
16. 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 >> Detect malfunctioning part according to EC-402, "
Symptom Matrix Chart" .
17. 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 >>INSPECTION END
NG (More than the SP value)>>GO TO 18.
NG (Less than the SP value)>>GO TO 25.
18. DETECT MALFUNCTIONING PART
1. Check for the cause of large engine friction. Refer to the following.
–Engine oil level is too high
–Engine oil viscosity
–Belt tension of power steering, alternator, A/C compressor, etc. is excessive
–Noise from engine
–Noise from transmission, etc.
2. Check for the cause of insufficient combustion. Refer to the following.
–Valve clearance malfunction
–Intake valve timing control function malfunction
–Camshaft sprocket installation malfunction, etc.
>> Repair or replace malfunctioning part, and then GO TO 30.
19. CHECK INTAKE SYSTEM
Check for the cause of uneven air flow through mass air flow sensor. Refer to the following.

Crushed air ducts

Malfunctioning seal of air cleaner element

Uneven dirt of air cleaner element

Improper specification of intake air system
OK or NG
OK >> GO TO 21.
NG >> Repair or replace malfunctioning part, and then GO TO 20.
PBIB2332E

POWER SUPPLY AND GROUND CIRCUIT
EC-451
[VQ]
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POWER SUPPLY AND GROUND CIRCUITPFP:24110
Wiring DiagramBBS004YO
TBWM1438E

EC-452
[VQ]
POWER SUPPLY AND GROUND CIRCUIT

Specification data are reference values and are measured between each terminal and ground.
CAUTION:
Do not use ECM ground terminals when measuring input/output voltage. Doing so may result in dam-
age to the ECM's transistor. Use a ground other than ECM terminals, such as the ground.
Diagnostic ProcedureBBS004YP
1. INSPECTION START
Start engine.
Is engine running?
Ye s o r N o
Yes >> GO TO 8.
No >> GO TO 2.
2. CHECK ECM POWER SUPPLY CIRCUIT-I
1. Turn ignition switch OFF and then ON.
2. Check voltage between ECM terminal 109 and ground with
CONSULT-II or tester.
OK or NG
OK >> GO TO 4.
NG >> GO TO 3.
3. DETECT MALFUNCTIONING PART
Check the following.

Fuse block (J/B) connector M1

10A fuse

Harness for open or short between ECM and fuse
>> Repair open circuit or short to ground or short to power in harness or connectors.
TER-
MINAL
NO.WIRE
COLORITEM CONDITION DATA (DC Voltage)
1 B ECM ground[Engine is running]

Idle speedBody ground
109 R Ignition switch[Ignition switch: OFF]0V
[Ignition switch: ON]BATTERY VOLTAGE
(11 - 14V)
111 W / BECM relay
(Self shut-off)[Engine is running]
[Ignition switch: OFF]

For a few seconds after turning ignition switch OFF0 - 1.0V
[Ignition switch: OFF]

More than a few seconds after turning ignition switch
OFFBATTERY VOLTAGE
(11 - 14V)
11 5
11 6B
BECM ground[Engine is running]

Idle speedBody ground
11 9
120R/G
R/GPower supply for
ECM[Ignition switch: ON]BATTERY VOLTAGE
(11 - 14V)
Voltage: Battery voltage
MBIB0015E

POWER SUPPLY AND GROUND CIRCUIT
EC-453
[VQ]
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4. CHECK GROUND CONNECTIONS
1. Turn ignition switch OFF.
2. Loosen and retighten two ground screws on the body.
Refer to EC-457, "
Ground Inspection" .
OK or NG
OK >> GO TO 5.
NG >> Repair or replace ground connections.
5. CHECK ECM GROUND CIRCUIT FOR OPEN AND SHORT-I
1. Disconnect ECM harness connector.
2. Check harness continuity between ECM terminals 1, 115, 116 and ground.
Refer to Wiring Diagram.
3. Also check harness for short to power.
OK or NG
OK >> GO TO 7.
NG >> GO TO 6.
6. DETECT MALFUNCTIONING PART
Check the following.

Harness connectors F103, M52

Harness for open or short between ECM and ground
>> Repair open circuit or short to power in harness or connectors.
7. CHECK ECM POWER SUPPLY CIRCUIT-II
1. Reconnect ECM harness connector.
2. Turn ignition switch ON.
3. Check voltage between IPDM E/R terminal 17 and ground with
CONSULT-II or tester.
OK or NG
OK >> Go to EC-735, "IGNITION SIGNAL" .
NG >> GO TO 8.
PBIB2160E
Continuity should exist.
Voltage: Battery voltage
PBIB1610E