DIAGNOSIS AND REPAIR WORKFLOW
EC-687
< BASIC INSPECTION >[MR18DE]
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YES >> GO TO 7.
NO >> GO TO 9.
7.PERFORM SPEC IN DATA MONITOR MODE
With CONSULT-III
Make sure that “MAS A/F SE-B1”, “B/FUEL SCHDL” and “A/F ALPHA-B1” are within the SP value using CON-
SULT-III in “SPEC” of “DATA MONITOR” mode. Refer to EC-781, "
Component Function Check".
Is the measurement value within the SP value?
YES >> GO TO 9.
NO >> GO TO 8.
8.DETECT MALFUNCTIONING PART BY TROUBLE DIAGNOSIS - SPECIFICATION VALUE
Detect malfunctioning part according to EC-782, "
Diagnosis Procedure".
Is malfunctioning part detected?
YES >> GO TO 11.
NO >> GO TO 9.
9.DETECT MALFUNCTIONING SYSTEM BY SYMPTOM TABLE
Detect malfunctioning system according to EC-1024, "
Symptom Table" based on the confirmed symptom in
step 4, and determine the trouble diagnosis order based on possible causes and symptom.
>> GO TO 10.
10.DETECT MALFUNCTIONING PART BY DIAGNOSIS PROCEDURE
Inspect according to Diagnosis Procedure of the system.
NOTE:
The Diagnosis Procedure in EC section described based on open circuit inspection. A short circuit inspection
is also required for the circuit check in the Diagnosis Procedure. For details, refer to Circuit Inspection in GI-
58, "Circuit Inspection".
Is malfunctioning part detected?
YES >> GO TO 11.
NO >> Monitor input data from related sensors or check the voltage of related ECM terminals using CON-
SULT-III. Refer to EC-990, "
Reference Value".
11 .REPAIR OR REPLACE THE MALFUNCTIONING PART
1. Repair or replace the malfunctioning part.
2. Reconnect parts or connectors disconnected during Diagnosis Procedure again after repair and replace-
ment.
3. Check DTC. If DTC is displayed, erase it. Refer to EC-760, "
Diagnosis Description".
>> GO TO 12.
12.FINAL CHECK
When DTC was detected in step 2, perform DTC CONFIRMATION PROCEDURE or Component 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.
Is DTC detected and does symptom remain?
YES-1 >> DTC is detected: GO TO 10.
YES-2 >> Symptom remains: GO TO 6.
NO >> Before returning the vehicle to the customer, make sure to erase unnecessary DTC in ECM and
TCM (Transmission Control Module). (Refer to EC-760, "
Diagnosis Description".) If the comple-
tion of SRT is needed, drive vehicle under the specific DRIVING PATTERN in EC-1021,
"HowtoSetSRTCode".
Diagnostic Work SheetINFOID:0000000001161701
DESCRIPTION
INSPECTION AND ADJUSTMENT
EC-693
< BASIC INSPECTION >[MR18DE]
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Check idle speed in “DATA MONITOR” mode with CONSULT-III.
With GST
Check idle speed with Service $01 of GST.
>> INSPECTION END
IGNITION TIMING
IGNITION TIMING : DescriptionINFOID:0000000001161707
This describes how to check the ignition timing. For the actual procedure, follow the instructions in “BASIC
INSPECTION”.
IGNITION TIMING : Special Repair RequirementINFOID:0000000001161708
1.CHECK IGNITION TIMING
1. Attach timing light to loop wire (1) as shown.
2. Check ignition timing.
>> INSPECTION END
ACCELERATOR PEDAL RELEASED POSITION LEARNING
ACCELERATOR PEDAL RELEASED POSITION LEARNING : DescriptionINFOID:0000000001161711
Accelerator Pedal Released Position Learning is a function of ECM to learn the fully released position of the
accelerator pedal by monitoring the accelerator pedal position sensor output signal. It must be performed each
time harness connector of accelerator pedal position sensor or ECM is disconnected.
ACCELERATOR PEDAL RELEASED POSITION LEARNING : Special Repair Re-
quirement
INFOID:0000000001161712
1.START
1. Make sure that accelerator pedal is fully released.
2. Turn ignition switch ON and wait at least 2 seconds.
3. Turn ignition switch OFF and wait at least 10 seconds.
4. Turn ignition switch ON and wait at least 2 seconds.
5. Turn ignition switch OFF and wait at least 10 seconds.
>> END
: Vehicle front
PBIB3320E
1 : Timing indicator
PBIB3263E
EC-694
< BASIC INSPECTION >[MR18DE]
INSPECTION AND ADJUSTMENT
THROTTLE VALVE CLOSED POSITION LEARNING
THROTTLE VALVE CLOSED POSITION LEARNING : DescriptionINFOID:0000000001161713
Throttle Valve Closed Position Learning is a function of ECM to learn the fully closed position of the throttle
valve by monitoring the throttle position sensor output signal. It must be performed each time harness connec-
tor of electric throttle control actuator or ECM is disconnected.
THROTTLE VALVE CLOSED POSITION LEARNING : Special Repair Requirement
INFOID:0000000001161714
1.START
1. Make sure that accelerator pedal is fully released.
2. Turn ignition switch ON.
3. Turn ignition switch OFF and wait at least 10 seconds.
Make sure that throttle valve moves during above 10 seconds by confirming the operating sound.
>> END
IDLE AIR VOLUME LEARNING
IDLE AIR VOLUME LEARNING : DescriptionINFOID:0000000001161715
Idle Air Volume Learning is a function of ECM to learn the idle air volume that keeps each engine idle speed
within the specific range. It must be performed under any of the following conditions:
Each time electric throttle control actuator or ECM is replaced.
Idle speed or ignition timing is out of specification.
IDLE AIR VOLUME LEARNING : Special Repair RequirementINFOID:0000000001161716
1.PRECONDITIONING
Make sure that all of the following conditions are satisfied.
Learning will be cancelled if any of the following conditions are missed for even a moment.
Battery voltage: More than 12.9V (At idle)
Engine coolant temperature: 70 - 100°C (158 - 212°F)
PNP switch: ON
Electric load switch: OFF
(Air conditioner, headlamp, rear window defogger)
On vehicles equipped with daytime light systems, set lighting switch to the 1st position to light only
small lamps.
Steering wheel: Neutral (Straight-ahead position)
Vehicle speed: Stopped
Transmission: Warmed-up
Drive vehicle for 10 minutes.
Do you have CONSULT-III?
YES >> GO TO 2.
NO >> GO TO 3.
2.IDLE AIR VOLUME LEARNING
With CONSULT-III
1. Perform Accelerator Pedal Released Position Learning. Refer to EC-693, "
ACCELERATOR PEDAL
RELEASED POSITION LEARNING : Special Repair Requirement".
2. Perform Throttle Valve Closed Position Learning. Refer to EC-694, "
THROTTLE VALVE CLOSED POSI-
TION LEARNING : Special Repair Requirement".
3. Start engine and warm it up to normal operating temperature.
4. Select “IDLE AIR VOL LEARN” in “WORK SUPPORT” mode.
5. Touch “START” and wait 20 seconds.
Is
“CMPLT” displayed on CONSULT-III screen?
YES >> GO TO 4.
NO >> GO TO 5.
INSPECTION AND ADJUSTMENT
EC-695
< BASIC INSPECTION >[MR18DE]
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3.IDLE AIR VOLUME LEARNING
Without CONSULT-III
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.
1. Perform Accelerator Pedal Released Position Learning. Refer to EC-693, "
ACCELERATOR PEDAL
RELEASED POSITION LEARNING : Special Repair Requirement".
2. Perform Throttle Valve Closed Position Learning. Refer to EC-694, "
THROTTLE VALVE CLOSED POSI-
TION LEARNING : Special Repair Requirement".
3. Start engine and warm it up to normal operating temperature.
4. Turn ignition switch OFF and wait at least 10 seconds.
5. Confirm that accelerator pedal is fully released, turn ignition switch ON and wait 3 seconds.
6. Repeat the following procedure quickly five times within 5 seconds.
- Fully depress the accelerator pedal.
- Fully release the accelerator pedal.
7. Wait 7 seconds, fully depress the accelerator pedal and keep it for approx. 20 seconds until the MI stops
blinking and turned ON.
8. Fully release the accelerator pedal within 3 seconds after the MI turned ON.
9. Start engine and let it idle.
10. Wait 20 seconds.
>> GO TO 4
4.CHECK IDLE SPEED AND IGNITION TIMING
Rev up the engine two or three times and make sure that idle speed and ignition timing are within the specifi-
cations. For specification, refer to EC-1038, "
Idle Speed" and EC-1038, "Ignition Timing".
Is the inspection result normal?
YES >> INSPECTION END
NO >> GO TO 5.
5.DETECT MALFUNCTIONING PART
Check the following
Check that throttle valve is fully closed.
Check PCV valve operation.
Check that downstream of throttle valve is free from air leakage.
Is the inspection result normal?
YES >> GO TO 6.
NO >> Repair or replace malfunctioning part.
6.DETECT MALFUNCTIONING PART
Engine component parts and their installation condition are questionable. Check and eliminate the cause of
the incident.
It is useful to perform “TROUBLE DIAGNOSIS - SPECIFICATION VALUE”. Refer to EC-781, "
Description".
If any of the following conditions occur after the engine has started, eliminate the cause of the incident and
perform Idle Air Volume Learning all over again:
Engine stalls.
Erroneous idle.
SEC897C
EC-696
< BASIC INSPECTION >[MR18DE]
INSPECTION AND ADJUSTMENT
>> INSPECTION END
MIXTURE RATIO SELF-LEARNING VALUE CLEAR
MIXTURE RATIO SELF-LEARNING VALUE CLEAR : DescriptionINFOID:0000000001161717
This describes how to erase the mixture ratio self-learning value. For the actual procedure, follow the instruc-
tions in “Diagnosis Procedure”.
MIXTURE RATIO SELF-LEARNING VALUE CLEAR : Special Repair Requirement
INFOID:0000000001161718
1.START
With CONSULT-III
1. Start engine and warm it up to normal operating temperature.
2. Select “SELF-LEARNING CONT” in “WORK SUPPORT” mode with CONSULT-III.
3. Clear mixture ratio self-learning value by touching “CLEAR”.
With GST
1. Start engine and warm it up to normal operating temperature.
2. Turn ignition switch OFF.
3. Disconnect mass air flow sensor harness connector.
4. Restart engine and let it idle for at least 5 seconds.
5. Stop engine and reconnect mass air flow sensor harness connector.
6. Select Service $03 with GST. Make sure DTC P0102 is detected.
7. Select Service $04 with GST to erase the DTC P0102.
>> END
EC-760
< FUNCTION DIAGNOSIS >[MR18DE]
ON BOARD DIAGNOSTIC (OBD) SYSTEM
ON BOARD DIAGNOSTIC (OBD) SYSTEM
Diagnosis DescriptionINFOID:0000000001161752
INTRODUCTION
The ECM has an on board diagnostic system, which detects malfunctions related to engine sensors or actua-
tors. The ECM also records various emission-related diagnostic information including:
The above information can be checked using procedures listed in the table below.
×: Applicable —: Not applicable
*: When DTC and 1st trip DTC simultaneously appear on the display, they cannot be clearly distinguished from each other.
The malfunction indicator (MI) on the instrument panel lights up when the same malfunction is detected in two
consecutive trips (Two trip detection logic), or when the ECM enters fail-safe mode. (Refer to EC-1017,
"FailSafe".)
TWO TRIP DETECTION LOGIC
When a malfunction is detected for the first time, 1st trip DTC and 1st trip Freeze Frame data are stored in the
ECM memory. The MI will not light up at this stage. <1st trip>
If the same malfunction is detected again during the next drive, the DTC and Freeze Frame data are stored in
the ECM memory, and the MI lights up. The MI lights up at the same time when the DTC is stored. <2nd trip>
The “trip” in the “Two Trip Detection Logic” means a driving mode in which self-diagnosis is performed during
vehicle operation. Specific on board diagnostic items will cause the ECM to light up or blink the MI, and store
DTC and Freeze Frame data, even in the 1st trip, as shown below.
×: Applicable —: Not applicable
DTC AND FREEZE FRAME DATA
DTC and 1st Trip DTC
Emission-related diagnostic information Diagnostic service
Diagnostic Trouble Code (DTC) Service $03 of ISO 15031-5
Freeze Frame data Service $02 of ISO 15031-5
System Readiness Test (SRT) code Service $01 of ISO 15031-5
1st Trip Diagnostic Trouble Code (1st Trip DTC) Service $07 of ISO 15031-5
1st Trip Freeze Frame data
Test values and Test limits Service $06 of ISO 15031-5
Calibration ID Service $09 of ISO 15031-5
DTC 1st trip DTCFreeze Frame
data1st trip Freeze
Frame dataSRT code Test value
CONSULT-III×× × × ×—
GST×× ×—××
ECM××*— — ——
ItemsMI DTC 1st trip DTC
1st trip 2nd trip
1st trip
displaying2nd trip
displaying1st trip
displaying2nd trip
display-
ing BlinkingLighting
upBlinkingLighting
up
Misfire (Possible three way catalyst
damage) — DTC: P0300 - P0304 is
being detected×———— —×—
Misfire (Possible three way catalyst
damage) — DTC: P0300 - P0304 is
being detected——×——×——
One trip detection diagnoses (Re-
fer to EC-1020, "
DTCIndex".)—×——×———
Except above — — —×—××—
EC-762
< FUNCTION DIAGNOSIS >[MR18DE]
ON BOARD DIAGNOSTIC (OBD) SYSTEM
(CONSULT-III also displays the malfunctioning component or system.)
No Tools
The number of blinks of the MI in the Diagnostic Test Mode II (Self-Diagnostic Results) indicates the DTC.
Example: 0340, 1148, 1706, etc.
These DTCs are controlled by NISSAN.
1st trip DTC No. is the same as DTC No.
Output of a DTC indicates a malfunction. However, GST or the Diagnostic Test Mode II do not indi-
cate whether the malfunction is still occurring or has occurred in the past and has returned to nor-
mal. CONSULT-III can identify malfunction status as shown below. Therefore, using CONSULT-III (if
available) is recommended.
DTC or 1st trip DTC of a malfunction is displayed in “SELF-DIAGNOSTIC RESULTS” mode of CONSULT-III.
Time data indicates how many times the vehicle was driven after the last detection of a DTC.
If the DTC is being detected currently, the time data will be [0].
If a 1st trip DTC is stored in the ECM, the time data will be [1t].
How to Erase DTC and 1st Trip DTC
With CONSULT-III
The emission related diagnostic information in the ECM can be erased by selecting “All Erase” in the “Descrip-
tion” of “FINAL CHECK” mode with CONSULT-III.
With GST
The emission related diagnostic information in the ECM can be erased by selecting Service $04 with GST.
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. Select Service $04 with GST (Generic Scan Tool).
No Tools
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. 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
- System readiness test (SRT) codes
- Test values
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.
SYSTEM READINESS TEST (SRT) CODE
System Readiness Test (SRT) code is specified in Service $01 of ISO 15031-5.
As part of an enhanced emissions test for Inspection & Maintenance (I/M), certain states require the status of
SRT be used to indicate whether the ECM has completed self-diagnosis of major emission systems and com-
ponents. Completion must be verified in order for the emissions inspection to proceed.
If a vehicle is rejected for a State emissions inspection due to one or more SRT items indicating “INCMP”, use
the information in this Service Manual to set the SRT to “CMPLT”.
In most cases the ECM will automatically complete its self-diagnosis cycle during normal usage, and the SRT
status will indicate “CMPLT” for each application system. Once set as “CMPLT”, the SRT status remains
“CMPLT” until the self-diagnosis memory is erased.
Occasionally, certain portions of the self-diagnostic test may not be completed as a result of the customer's
normal driving pattern; the SRT will indicate “INCMP” for these items.
NOTE:
The SRT will also indicate “INCMP” if the self-diagnosis memory is erased for any reason or if the ECM mem-
ory power supply is interrupted for several hours.
If, during the state emissions inspection, the SRT indicates “CMPLT” for all test items, the inspector will con-
tinue with the emissions test. However, if the SRT indicates “INCMP” for one or more of the SRT items the
vehicle is returned to the customer untested.
NOTE:
EC-766
< FUNCTION DIAGNOSIS >[MR18DE]
ON BOARD DIAGNOSTIC (OBD) SYSTEM
In this mode, the MI on the instrument panel should stay ON. If it remains OFF, check MI circuit. Refer to MWI-
15, "WARNING LAMPS/INDICATOR LAMPS : System Diagram".
Diagnostic Test Mode I — Malfunction Warning
This DTC number is clarified in Diagnostic Test Mode II (SELF-DIAGNOSTIC RESULTS)
Diagnostic Test Mode II — Self-diagnostic Results
In this mode, the DTC and 1st trip DTC are indicated by the number of blinks of the MI as shown below.
The DTC and 1st trip DTC are displayed at the same time. If the MI does not illuminate in diagnostic test mode
I (Malfunction warning), all displayed items are 1st trip DTCs. If only one code is displayed when the MI illumi-
nates in diagnostic test mode II (SELF-DIAGNOSTIC RESULTS), it is a DTC; if two or more codes are dis-
played, they may be either DTCs or 1st trip DTCs. DTC No. is same as that of 1st trip DTC. These unidentified
codes can be identified by using the CONSULT-III or GST. A DTC will be used as an example for how to read
a code.
A particular trouble code can be identified by the number of four-digit numeral flashes. The “zero” is indicated
by the number of ten flashes. The length of time the 1,000th-digit numeral flashes on and off is 1.2 seconds
consisting of an ON (0.6-second) - OFF (0.6-second) cycle.
The 100th-digit numeral and lower digit numerals consist of a 0.3-second ON and 0.3-second OFF cycle.
A change from one digit numeral to another occurs at an interval of 1.0-second OFF. In other words, the later
numeral appears on the display 1.3 seconds after the former numeral has disappeared.
A change from one trouble code to another occurs at an interval of 1.8-second OFF.
In this way, all the detected malfunctions are classified by their DTC numbers. The DTC 0000 refers to no mal-
function. (See EC-1020, "
DTCIndex".)
HOW TO ERASE DIAGNOSTIC TEST MODE II (SELF-DIAGNOSTIC RESULTS)
The DTC can be erased from the back up memory in the ECM by depressing accelerator pedal. Refer to
“HOW to ERASE DIAGNOSTIC TEST MODE II (SELF-DIAGNOSTIC RESULTS)”.
If the battery is disconnected, the DTC will be lost from the backup memory within 24 hours.
Be careful not to erase the stored memory before starting trouble diagnoses.
Diagnostic Test Mode II — Heated Oxygen Sensor 1 Monitor
In this mode, the MI displays the condition of the fuel mixture (lean or rich) which is monitored by the heated
oxygen sensor 1.
MI Condition
ON When the malfunction is detected.
OFF No malfunction.
PBIA3905E
MI Fuel mixture condition in the exhaust gas Air fuel ratio feedback control condition
ON Lean
Closed loop system
OFF Rich
*Remains ON or OFF Any condition Open loop system