EC-36
[QR]
ON BOARD DIAGNOSTIC (OBD) SYSTEM
1. If the ignition switch stays ON after repair work, be sure to turn ignition switch OFF once. Wait at least 10
seconds and then turn it ON (engine stopped) again.
2. Touch “ENGINE”.
3. Touch “SELF-DIAG RESULTS”.
4. Touch “ERASE”. (The DTC in the ECM will be erased.)
Without CONSULT-II
1. If the ignition switch stays ON after repair work, be sure to turn ignition switch OFF once.
2. Wait at least 10 seconds and then turn it ON (engine stopped) again.
3. Change the diagnostic test mode from Mode II to Mode I by depressing the accelerator pedal.
If the battery is disconnected, the emission-related diagnostic information will be lost within 24
hours.
The following data are cleared when the ECM memory is erased.
–Diagnostic trouble codes
–1st trip diagnostic trouble codes
–Freeze frame data
–1st trip freeze frame data
Actual work procedures are explained using a DTC as an example. Be careful so that not only the DTC, but all
of the data listed above, are cleared from the ECM memory during work procedures.
Malfunction Indicator (MI)BBS005BS
DESCRIPTION
The MI is located on the instrument panel.
1. The MI will light up when the ignition switch is turned ON without
the engine running. This is a bulb check.
If the MI does not light up, refer to DI-35, "
WARNING LAMPS"
or see EC-344, "MI & DATA LINK CONNECTORS" .
2. When the engine is started, the MI should go off.
If the MI remains on, the on board diagnostic system has
detected an engine system malfunction.
ON BOARD DIAGNOSTIC SYSTEM FUNCTION
The on board diagnostic system has the following four functions.
PBIB2496E
SAT652J
ON BOARD DIAGNOSTIC (OBD) SYSTEM
EC-37
[QR]
C
D
E
F
G
H
I
J
K
L
MA
EC
When there is an open circuit on MI circuit, the ECM can not warn the driver by lighting up MI when there is
trouble on engine control system.
Therefore, when Electrical controlled throttle and part of the ECM related diagnoses are continuously detected
as NG for 5-trips, ECM warns the driver that engine control system has trouble 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 trouble.
MI Flashing without DTC
If the ECM is in Diagnostic Test Mode II, MI may flash when engine is running. In this case, check ECM diag-
nostic test mode. EC-37, "
HOW TO SWITCH DIAGNOSTIC TEST MODE" .
How to switch the diagnostic test (function) modes, and details of the above functions are described later, EC-
37 .
The following emission-related diagnostic information is cleared when the ECM memory is erased.
Diagnostic trouble codes
1st trip diagnostic trouble codes
Freeze frame data
1st trip freeze frame data
Others
HOW TO SWITCH DIAGNOSTIC TEST MODE
NOTE:
It is better to count the time accurately with a clock.
It is impossible to switch the diagnostic mode when an accelerator pedal position sensor circuit
has a malfunction.
Diagnostic Test
ModeKEY and ENG.
StatusFunction Explanation of Function
Mode I Ignition switch in
ON position
Engine stoppedBULB CHECK This function checks the MI bulb for damage (blown, open
circuit, etc.).
If the MI does not come on, check MI circuit.
Engine running MALFUNCTION
WARNINGThis is a usual driving condition. When a malfunction is
detected twice in two consecutive driving cycles (two trip
detection logic), the MI will light up to inform the driver that
a malfunction has been detected.
The following malfunctions will light up or blink the MI in
the 1st trip.
One trip detection diagnoses
Mode II Ignition switch in
ON position
Engine stoppedSELF-DIAGNOSTIC
RESULTSThis function allows DTCs and 1st trip DTCs to be read.
Engine running HEATED OXYGEN SENSOR 1
MONITORThis function allows the fuel mixture condition (lean or
rich), monitored by heated oxygen sensor 1, to be read.
Engine operating condition in fail-safe mode Engine speed will not rise more than 2,500 rpm due to the fuel cut
BASIC SERVICE PROCEDURE
EC-43
[QR]
C
D
E
F
G
H
I
J
K
L
MA
EC
10. CHECK IGNITION TIMING
1. Run engine at idle.
2. Check ignition timing with a timing light.
Refer to EC-45, "
IGNITION TIMING" .
OK or NG
OK >>INSPECTION END
NG >> GO TO 11.
11 . PERFORM ACCELERATOR PEDAL RELEASED POSITION LEARNING
1. Stop engine.
2. Perform EC-47, "
Accelerator Pedal Released Position Learning" .
>> GO TO 12.
12. PERFORM THROTTLE VALVE CLOSED POSITION LEARNING
Perform EC-47, "
Throttle Valve Closed Position Learning" .
>> GO TO 13.
13. PERFORM IDLE AIR VOLUME LEARNING
Refer to EC-47, "
Idle Air Volume Learning" .
Is Idle Air Volume Learning carried out successfully?
Ye s o r N o
Ye s > > G O T O 1 4 .
No >> 1. Follow the instruction of Idle Air Volume Learning.
2. GO TO 4. 15 ± 5° BTDC (in P or N position)
PBIB2177E
EC-44
[QR]
BASIC SERVICE PROCEDURE
14. CHECK TARGET IDLE SPEED AGAIN
With CONSULT-II
1. Start engine and warm it up to normal operating temperature.
2. Read idle speed in “DATA MONITOR” mode with CONSULT-II.
Refer to EC-45, "
IDLE SPEED" .
Without CONSULT-II
1. Start engine and warm it up to normal operating temperature.
2. Check idle speed.
Refer to EC-45, "
IDLE SPEED" .
OK or NG
OK >> GO TO 15.
NG >> GO TO 17.
15. CHECK IGNITION TIMING AGAIN
1. Run engine at idle.
2. Check ignition timing with a timing light.
Refer to EC-45, "
IGNITION TIMING" .
OK or NG
OK >>INSPECTION END
NG >> GO TO 16.
16. CHECK TIMING CHAIN INSTALLATION
Check timing chain installation. Refer to EM-53, "
TIMING CHAIN" .
OK or NG
OK >> GO TO 17.
NG >> 1. Repair the timing chain installation.
2. GO TO 4. 700 ± 50 rpm (in P or N position)
700 ± 50 rpm (in P or N position)
15 ± 5° BTDC (in P or N position)
PBIB2177E
BASIC SERVICE PROCEDURE
EC-45
[QR]
C
D
E
F
G
H
I
J
K
L
MA
EC
17. DETECT MALFUNCTIONING PART
Check the following.
Check camshaft position sensor (PHASE) and circuit. Refer to EC-176 .
Check crankshaft position sensor (POS) and circuit. Refer to EC-169 .
OK or NG
OK >> GO TO 18.
NG >> 1. Repair or replace.
2. GO TO 4.
18. CHECK ECM FUNCTION
1. Substitute another known-good ECM to check ECM function. (ECM may be the cause of an incident, but
this is a rare case.)
2. Perform initialization of NATS system and registration of all NATS ignition key IDs. Refer to BL-139,
"NATS(Nissan Anti-Theft System)" .
>> GO TO 4.
Idle Speed and Ignition Timing CheckBBS005BU
IDLE SPEED
With CONSULT-II
Check idle speed in “DATA MONITOR” mode with CONSULT-II.
Without CONSULT-II
Check the idle speed by installing the pulse type tachometer clamp on the loop wire or on suitable high-tension
wire which installed between No.1 ignition coil and No.1 spark plug.
NOTE:
For the method of installing the tachometer, refer to EC-45, "
IGNITION TIMING" .
IGNITION TIMING
Any of following two methods may be used.
Method A
1. Slide the harness protector of ignition coil No.1 to clear the
wires.
2. Attach timing light to the wire as shown in the figure.
SEF058Y
PBIB2137E
EC-46
[QR]
BASIC SERVICE PROCEDURE
3. Check ignition timing.
Method B
1. Remove ignition coil No. 1.
2. Connect No. 1 ignition coil and No. 1 spark plug with suitable
high-tension wire as shown, and attach timing light clamp to this
wire.
PBIB2177E
PBIB2132E
PBIB2138E
SEF166Y
TROUBLE DIAGNOSIS
EC-59
[QR]
C
D
E
F
G
H
I
J
K
L
MA
EC
Fail-Safe ChartBBS005C1
When the DTC listed bellow is detected, the ECM enters fail-safe mode and the MI lights up.
When there is an open circuit on MI circuit, the ECM can not warn the driver by lighting up MI when there is
trouble on engine control system. Therefore, when Electrical controlled throttle and part of the ECM related
diagnoses are continuously detected as NG for 5-trips, ECM warns the driver that engine control system has
trouble 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 trouble.
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
P0221
P0222
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.
(ECM detect 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.
P1805 Brake switchECM controls the electric throttle control actuator by regulating the throttle opening to a
small range.
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-78
[QR]
TROUBLE DIAGNOSIS
98 LGAccelerator pedal position
sensor 2[Ignition switch: ON]
Engine stopped
Accelerator pedal: Fully released0.28 - 0.48V
[Ignition switch: ON]
Engine stopped
Accelerator pedal: Fully depressedMore than 2.0V
101 R/G Stop lamp switch[Ignition switch: OFF]
Brake pedal: Fully releasedApproximately 0V
[Ignition switch: OFF]
Brake pedal: Slightly depressedBATTERY VOLTAGE
(11 - 14V)
102 G/W PNP switch[Ignition switch: ON]
Shift lever: P or NApproximately 0V
[Ignition switch: ON]
Except above positionBATTERY VOLTAGE
(11 - 14V)
103 W/LTachometer signal
output[Engine is running]
Warm-up condition
Idle speed
NOTE:
The pulse cycle changes depending on
rpm at idle.10 - 11V
[Engine is running]
Engine speed is 2,000 rpm10 - 11V
104 O Throttle control motor relay[Ignition switch: OFF]BATTERY VOLTAGE
(11 - 14V)
[Ignition switch: ON]0 - 1.0V
106 WAccelerator pedal position
sensor 1[Ignition switch: ON]
Engine stopped
Accelerator pedal: Fully released0.65 - 0.87V
[Ignition switch: ON]
Engine stopped
Accelerator pedal: Fully depressedMore than 4.3V
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 igni-
tion switch OFFBATTERY VOLTAGE
(11 - 14V) TERMI-
NAL
NO.WIRE
COLORITEM CONDITION DATA (DC Voltage)
MBIB0053E
MBIB0054E