Engine Control System (Introduction): Overview Nissan Quest IV

DESCRIPTION

The ECM controls the cooling fan corresponding to the vehicle speed, engine coolant temperature, refrigerant pressure, and air conditioner ON signal. The control system has 4-step control [HIGH/MIDDLE/LOW/OFF]. Refer to " COOLING FAN CONTROL: SYSTEM DESCRIPTION " for cooling fan operation.

The air fuel ratio (A/F) sensor 1 is a planar one-cell limit current sensor. The sensor element of the A/F sensor 1 is composed an electrode layer, which transports ions. It has a heater in the element.

The sensor is capable of precise measurement lambda = 1, but also in the lean and rich range. Together with its control electronics, the sensor outputs a clear, continuous signal throughout a wide lambda range.

The exhaust gas components diffuse through the diffusion layer at the sensor cell. An electrode layer is applied voltage, and this current relative oxygen density in lean. Also this current relative hydrocarbon density in rich.

Scheme 1

Therefore, the A/F sensor 1 is able to indicate air fuel ratio by this electrode layer of current. In addition, a heater is integrated in the sensor to ensure the required operating temperature of approximately 800°C (1, 472°F).

Scheme 2

The heated oxygen sensor 2, after three way catalyst (manifold), monitors the oxygen level in the exhaust gas.

Even if switching characteristics of the air fuel ratio (A/F) sensor 1 are shifted, the air fuel ratio is controlled to stoichiometric, by the signal from the heated oxygen sensor 2.

This sensor is made of ceramic zirconia. The zirconia generates voltage from approximately 1 V in richer conditions to 0 V in leaner conditions.

Under normal conditions the heated oxygen sensor 2 is not used for engine control operation.

Scheme 3

SYSTEM DESCRIPTION

ECM controls the engine by various functions.

Scheme 4

Scheme 5

Scheme 6

Scheme 7

The amount of fuel injected from the fuel injector is determined by the ECM. The ECM controls the length of time the valve remains open (injection pulse duration). The amount of fuel injected is a program value in the ECM memory. The program value is preset by engine operating conditions. These conditions are determined by input signals (for engine speed and intake air) from the crankshaft position sensor (POS), camshaft position sensor (PHASE) and the mass air flow sensor.

Ignition order: 1 - 2 - 3 - 4 - 5 - 6

The ignition timing is controlled by the ECM to maintain the best air-fuel ratio for every running condition of the engine. The ignition timing data is stored in the ECM.

The ECM receives information such as the injection pulse width and camshaft position sensor (PHASE) signal. Computing this information, ignition signals are transmitted to the power transistor.

During the following conditions, the ignition timing is revised by the ECM according to the other data stored in the ECM.

1. At starting
2. During warm-up
3. At idle
4. At low battery voltage
5. During acceleration

The knock sensor retard system is designed only for emergencies. The basic ignition timing is programmed within the anti-knocking zone, if recommended fuel is used under dry conditions. The retard system does not operate under normal driving conditions. If engine knocking occurs, the knock sensor monitors the condition. The signal is transmitted to the ECM. The ECM retards the ignition timing to eliminate the knocking condition.

Scheme 8

This system improves engine operation when the air conditioner is used.

Under the following conditions, the air conditioner is turned OFF.

1. When the accelerator pedal is fully depressed.
2. When cranking the engine.
3. At high engine speeds.
4. When the engine coolant temperature becomes excessively high.
5. When operating power steering during low engine speed or low vehicle speed.
6. When engine speed is excessively low.
7. When refrigerant pressure is excessively low or high.

Scheme 9

SET OPERATION

Press MAIN switch. (The CRUISE on combination meter illuminates.)

When vehicle speed reaches a desired speed between approximately 40 km/h (25 MPH) and 144 km/h (89 MPH), press SET/COAST switch.

ACCELERATE OPERATION

If the RESUME/ACCELERATE switch is pressed during cruise control driving, increase the vehicle speed until the switch is released or vehicle speed reaches maximum speed controlled by the system.

And then ASCD will maintain the new set speed.

CANCEL OPERATION

When any of following conditions exist, cruise operation will be canceled.

1. CANCEL switch is pressed
2. More than 2 switches on ASCD steering switch are pressed at the same time (Set speed will be cleared)
3. Brake pedal is depressed
4. Selector lever position changed to N, P or R
5. Vehicle speed decreased to 13 km/h (8 MPH) lower than the set speed
6. TCS system is operated
7. CVT control system has a malfunction. Refer to " «DESCRIPTION»(/nissan/quest/iv-2010-2024/remont/testing-diagnostics/#engine-control-system-diagnostic-codes-symptom-tests) ".
8. Engine coolant temperature is slightly higher than the normal operating temperature

When the ECM detects any of the following conditions, the ECM will cancel the cruise operation and inform the driver by blinking indicator lamp.

1. Malfunction for some self-diagnoses regarding ASCD control: CRUISE will blink quickly.

If MAIN switch is turned to OFF while ASCD is activated, all of ASCD operations will be canceled and vehicle speed memory will be erased.

COAST OPERATION

When the SET/COAST switch is pressed during cruise control driving, decrease vehicle set speed until the switch is released. And then ASCD will maintain the new set speed.

RESUME OPERATION

When the RESUME/ACCELERATE switch is pressed after canceling operation other than pressing the MAIN switch is performed, vehicle speed will return to last set speed. To resume vehicle set speed, vehicle condition must meet following conditions.

1. Brake pedal is released
2. Selector lever position is other than P and N
3. Vehicle speed is greater than 40 km/h (25 MPH) and less than 144 km/h (89 MPH)

Scheme 10

The ECM controls the cooling fan corresponding to the vehicle speed, engine coolant temperature, refrigerant pressure, and air conditioner ON signal. The control system has 4-step control [HIGH/MIDDLE/LOW/OFF].

Cooling Fan Operation

Scheme 11

Cooling Fan Relay Operation

The ECM controls cooling fan relays in the IPDM E/R through CAN communication line.

Scheme 12

The ECM controls the engine mount operation corresponding to the engine speed. The control system has a 2-step control [Soft/Hard]

Scheme 13

Scheme 14

Note. Do not use soapy water or any type of solvent while installing vacuum hose.

Scheme 15

The fuel filler cap warning system alerts the driver to the prevention of the fuel filler being left uncapped and malfunction occurrences after refueling, by turning ON the fuel filler cap warning display on the combination meter.

ECM judges a refueled state, based on a fuel level signal transmitted from the combination meter.

When a very small leak is detected through the EVAP leak diagnosis performed after judging the refueled state, ECM transmits a fuel filler cap warning display signal (request for display ON) to the combination meter via CAN communication.

When receiving the signal, the combination meter turns ON the fuel filler cap warning display.

Reset Operation

The fuel filler cap warning lamp tunes OFF, according to any condition listed below

1. Reset operation is performed by operating the meter control switch on the combination meter. When the reset operation is performed, the combination meter transmits a fuel filler cap warning reset signal to ECM via CAN communication. ECM transmits a fuel filler cap warning display signal (request for display OFF) to the combination meter via CAN communication. When receiving the signal, the combination meter turns OFF the fuel filler cap warning display.
2. EVAP leak diagnosis result is normal.
3. Fuel refilled.
4. DTC erased by using CONSULT.

Note. MIL turns ON if a malfunction is detected in leak diagnosis results again at the trip after the fuel filler cap warning display turns ON/OFF.

Scheme 16

CAN COMMUNICATION: System Description

CAN (Controller Area Network) is a serial communication line for real time application. It is an on-vehicle multiplex communication line with high data communication speed and excellent error detection ability. Many electronic control units are equipped onto a vehicle, and each control unit shares information and links with other control units during operation (not independent). In CAN communication, control units are connected with 2 communication lines (CAN H line, CAN L line) allowing a high rate of information transmission with less wiring. Each control unit transmits/receives data but selectively reads required data only.

Refer to " CAN COMMUNICATION SYSTEM: CAN COMMUNICATION SIGNAL CHART ", about CAN communication for detail.

Scheme 17

When rapid deceleration occurs during engine runs or idle speed decreases due to heavy load conditions, ECM detects a decrease in idle speed and restarts the engine to increase stability by transmitting a cranking request signal to IPDM E/R for activating the starter motor under the following conditions

1. Selector lever: P or any position other than N
2. Idle switch: ON (Accelerator pedal not depressed)
3. Stop lamp switch: ON (Brake pedal depressed)

Models with no Intelligent Key System transmit a control signal directly to IPDM E/R. On the other hand, models with the Intelligent Key System transmit a control signal to IPDM E/R by way of BCM via CAN communication.

IPDM E/R detects an operating state of the starter motor relay and the starter motor control relay and transmits a feed back signal to ECM via CAN Communication.

Scheme 18

SWITCH OPERATION

Diagnosis Description

This system is an on board diagnostic system that records exhaust emission-related diagnostic information and detects a sensors/actuator-related malfunction. A malfunction is indicated by the malfunction indicator lamp (MIL) and stored in ECU memory as a DTC. The diagnostic information can be obtained with the diagnostic tool (GST: Generic Scan Tool).

DIAGNOSIS DESCRIPTION: 1st Trip Detection Logic and 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 MIL will not illuminate 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 MIL illuminates. The MIL illuminates 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 illuminate or blink the MIL, and store DTC and Freeze Frame data, even in the 1st trip, as shown below.

DIAGNOSIS DESCRIPTION: Driving Pattern

DIAGNOSIS DESCRIPTION: System Readiness Test (SRT) Code

System Readiness Test (SRT) code is specified in Service $01 of SAE J1979/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 components. 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 Information 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 memory power supply is interrupted for several hours.

If, during the state emissions inspection, the SRT indicates "CMPLT" for all test items, the inspector will continue 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. If permanent DTC is stored or MIL illuminates during the state emissions inspection, the vehicle is also returned to the customer untested even though the SRT indicates "CMPLT" for all test items. Therefore, it is important to check SRT ("CMPLT"), DTC (No DTCs) and permanent DTC (NO permanent DTCs) before the inspection.

DIAGNOSIS DESCRIPTION: Permanent Diagnostic Trouble Code (Permanent DTC)

Permanent DTC is defined in SAE J1979/ISO 15031-5 Service $0A.

ECM stores a DTC issuing a command of turning on MIL as a permanent DTC and keeps storing the DTC as a permanent DTC until ECM judges that there is no presence of malfunction.

Permanent DTCs cannot be erased by using the Erase function of CONSULT-III or Generic Scan Tool (GST) and by disconnecting the battery to shut off power to ECM. This prevents a vehicle from passing the state emission inspection without repairing a malfunctioning part.

When not passing the state emission inspection due to more than one permanent DTC, permanent DTCs should be erased, referring to this article.

Note. The important items in state emission inspection are that MIL is not ON, SRT test items are set, and permanent DTCs are not included. Permanent DTCs do not apply for regions that permanent DTCs are not regulated by law.

DIAGNOSIS DESCRIPTION: Malfunction Indicator Lamp (MIL)

When emission-related ECU detects a malfunction in the emission control systems components and/or the powertrain control components (which affect vehicle emissions), it turns on/blinks MIL to inform the driver that a malfunction has been detected.

1. The MIL illuminates when ignition switch is turned ON (engine is not running). NOTE: Check the MIL circuit if MIL does not illuminate. Refer to " «COMPONENT FUNCTION CHECK»(/nissan/quest/iv-2010-2024/remont/testing-diagnostics/#engine-control-system-diagnostic-codes-symptom-tests) ".
2. When the engine is started, the MIL should go off. NOTE: If MIL continues to illuminate/blink, perform self-diagnoses and inspect/repair accordingly because an emission-related ECU has detected a malfunction in the emission control systems components and/or the powertrain control components (which affect vehicle emissions).

There are many operating conditions that lead to the malfunction of engine components. A good grasp of such conditions can make troubleshooting faster and more accurate.

In general, each customer feels differently about symptoms. It is important to fully understand the symptoms or conditions for a customer complaint.

Utilize a diagnostic worksheet like the WORKSHEET SAMPLE below in order to organize all the information for troubleshooting. Some conditions may cause the MIL to illuminate or blink, and DTC to be detected. Examples

Scheme 19

1. Vehicle ran out of fuel, which caused the engine to misfire.
2. Fuel filler cap was left off or incorrectly screwed on, allowing fuel to evaporate into the atmosphere.

Scheme 20

Scheme 21

Scheme 22

Scheme 23

Scheme 24

1. INSPECTION START Check service records for any recent repairs that may indicate a related malfunction, or a current need for scheduled maintenance. Open engine hood and check the following: Harness connectors for improper connections Wiring harness for improper connections, pinches and cut Vacuum hoses for splits, kinks and improper connections Hoses and ducts for leakage Air cleaner clogging Gasket Check that electrical or mechanical loads are not applied. Head lamp switch is OFF. Air conditioner switch is OFF. Rear window defogger switch is OFF. Steering wheel is in the straight-ahead position, etc. Start engine and warm it up until engine coolant temperature indicator points to the middle of gauge. Check that engine stays below 1, 000 rpm. Run engine at approximately 2, 000 rpm for approximately 2 minutes under no load. Check that no DTC is displayed with CONSULT or GST. Are any DTCs detected? YES: GO TO 2. NO: GO TO 3 .
2. REPAIR OR REPLACE Repair or replace components as necessary according to corresponding Diagnostic Procedure. : GO TO 3
3. CHECK TARGET IDLE SPEED Run engine at approximately 2, 000 rpm for approximately 2 minutes under no load. Rev engine (2, 000 to 3, 000 rpm) 2 or 3 times under no load, then run engine at idle speed for approximately 1 minute. Check idle speed. For procedure, refer to " «WORK PROCEDURE»(/nissan/quest/iv-2010-2024/remont/testing-diagnostics/#engine-control-system-diagnostic-codes-symptom-tests) ". For specification, refer to " «IDLE SPEED»(/nissan/quest/iv-2010-2024/remont/testing-diagnostics/#engine-control-system-diagnostic-codes-symptom-tests) ". Is the inspection result normal? YES: GO TO 10 . NO: GO TO 4.
4. PERFORM ACCELERATOR PEDAL RELEASED POSITION LEARNING Stop engine. Perform " «WORK PROCEDURE»(ref-672625-S42429012022014112400000) ".: GO TO 5.
5. PERFORM THROTTLE VALVE CLOSED POSITION LEARNING Perform " «WORK PROCEDURE»(ref-672625-S35212184942014112400000) ".: GO TO 6.
6. PERFORM IDLE AIR VOLUME LEARNING Perform " «WORK PROCEDURE»(ref-672625-S41087216452014112400000) ". Is Idle Air Volume Learning carried out successfully? YES: GO TO 7. NO: Follow the instruction of Idle Air Volume Learning. Then GO TO 4.
7. CHECK IDLE SPEED AGAIN Start engine and warm it up to normal operating temperature. Check idle speed. For procedure, refer to " «WORK PROCEDURE»(/nissan/quest/iv-2010-2024/remont/testing-diagnostics/#engine-control-system-diagnostic-codes-symptom-tests) ". For specification, refer to " «IDLE SPEED»(/nissan/quest/iv-2010-2024/remont/testing-diagnostics/#engine-control-system-diagnostic-codes-symptom-tests) ". Is the inspection result normal? YES: GO TO 10 . NO: GO TO 8.
8. DETECT MALFUNCTIONING PART Check the Following. Check camshaft position sensor (PHASE) and circuit. Refer to " «DIAGNOSIS PROCEDURE»(/nissan/quest/iv-2010-2024/remont/testing-diagnostics/#engine-control-system-diagnostic-codes-symptom-tests) ". Check crankshaft position sensor (POS) and circuit. Refer to " «DIAGNOSIS PROCEDURE»(/nissan/quest/iv-2010-2024/remont/testing-diagnostics/#engine-control-system-diagnostic-codes-symptom-tests) ". Is the inspection result normal? YES: GO TO 9. NO: Repair or replace malfunctioning part. Then GO TO 4 .
9. CHECK ECM FUNCTION Substitute with a non-malfunctioning ECM to check ECM function. (ECM may be the cause of the incident, although this is rare.) Perform initialization of NVIS (NATS) system and registration of all NVIS (NATS) ignition key IDs. Refer to " «ECM: WORK PROCEDURE»(ref-672643-S14948856922014112400000) ".: GO TO 4.
10. CHECK IGNITION TIMING Run engine at idle. Check ignition timing with a timing light. For procedure, refer to " «WORK PROCEDURE»(/nissan/quest/iv-2010-2024/remont/testing-diagnostics/#engine-control-system-diagnostic-codes-symptom-tests) ". For specification, refer to " «IGNITION TIMING»(/nissan/quest/iv-2010-2024/remont/testing-diagnostics/#engine-control-system-diagnostic-codes-symptom-tests) ". Is the inspection result normal? YES: GO TO 19 . NO: GO TO 11.
11. PERFORM ACCELERATOR PEDAL RELEASED POSITION LEARNING Stop engine. Perform " «WORK PROCEDURE»(ref-672625-S42429012022014112400000) ".: GO TO 12.
12. PERFORM THROTTLE VALVE CLOSED POSITION LEARNING Perform " «WORK PROCEDURE»(ref-672625-S35212184942014112400000) ".: GO TO 13.
13. PERFORM IDLE AIR VOLUME LEARNING Perform " «WORK PROCEDURE»(ref-672625-S41087216452014112400000) ". Is Idle Air Volume Learning carried out successfully? YES: GO TO 14. NO: Follow the instruction of Idle Air Volume Learning. Then GO TO 4.
14. CHECK IDLE SPEED AGAIN Start engine and warm it up to normal operating temperature. Check idle speed. For procedure, refer to " «WORK PROCEDURE»(/nissan/quest/iv-2010-2024/remont/testing-diagnostics/#engine-control-system-diagnostic-codes-symptom-tests) ". For specification, refer to " «IDLE SPEED»(/nissan/quest/iv-2010-2024/remont/testing-diagnostics/#engine-control-system-diagnostic-codes-symptom-tests) ". Is the inspection result normal? YES: GO TO 15. NO: GO TO 17 .
15. CHECK IGNITION TIMING AGAIN Run engine at idle. Check ignition timing with a timing light. For procedure, refer to " «WORK PROCEDURE»(/nissan/quest/iv-2010-2024/remont/testing-diagnostics/#engine-control-system-diagnostic-codes-symptom-tests) ". For specification, refer to " «IGNITION TIMING»(/nissan/quest/iv-2010-2024/remont/testing-diagnostics/#engine-control-system-diagnostic-codes-symptom-tests) ". Is the inspection result normal? YES: GO TO 19 . NO: GO TO 16.
16. CHECK TIMING CHAIN INSTALLATION Check timing chain installation. Refer to " «INSPECTION»(ref-672620-S06568957502014112400000) ". Is the inspection result normal? YES: GO TO 17. NO: Repair the timing chain installation. Then GO TO 4.
17. DETECT MALFUNCTIONING PART Check the following. Check camshaft position sensor (PHASE) and circuit. Refer to " «DIAGNOSIS PROCEDURE»(/nissan/quest/iv-2010-2024/remont/testing-diagnostics/#engine-control-system-diagnostic-codes-symptom-tests) ". Check crankshaft position sensor (POS) and circuit. Refer to " «DIAGNOSIS PROCEDURE»(/nissan/quest/iv-2010-2024/remont/testing-diagnostics/#engine-control-system-diagnostic-codes-symptom-tests) ". Is the inspection result normal? YES: GO TO 18. NO: Repair or replace malfunctioning part. Then GO TO 4 .
18. CHECK ECM FUNCTION Substitute with a non-malfunctioning ECM to check ECM function. (ECM may be the cause of the incident, although this is rare.) Perform initialization of NVIS (NATS) system and registration of all NVIS (NATS) ignition key IDs. Refer to " «WORK PROCEDURE»(ref-672625-S31399234192014112400000) ".: GO TO 4.
19. INSPECTION END If ECM is replaced during this BASIC INSPECTION procedure, perform " «WORK PROCEDURE»(ref-672625-S31399234192014112400000) ".: INSPECTION END

When replacing ECM, the following procedure must be performed. (For details, refer to " WORK PROCEDURE ".)

PROGRAMMING OPERATION

Note. After replacing with a blank ECM, programming is required to write ECM information. Be sure to follow the procedure to perform the programming.

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 the harness connector of the accelerator pedal position sensor or ECM is disconnected.

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 the harness connector of electric throttle control actuator or ECM is disconnected or electric throttle control actuator is cleaned.

Idle Air Volume Learning is a function of ECM to learn the idle air volume that keeps engine idle speed within the specific range. It must be performed under the following conditions

1. Each time the electric throttle control actuator or ECM is replaced.
2. Idle speed or ignition timing is out of the specification.

Scheme 25

1. PRECONDITIONING Check 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 12.9 V (At idle) Engine coolant temperature: 70 - 100°C (158 - 212°F) Selector lever position: P or N Electric load switch: OFF (Air conditioner, head lamp, rear window defogger) On vehicles equipped with daytime light systems, if the parking brake is applied before the engine is started the head lamp will not illuminate. Steering wheel: Neutral (Straight-ahead position) Vehicle speed: Stopped Transmission: Warmed-up With CONSULT: Drive vehicle until "ATF TEMP SEN" in "DATA MONITOR" mode of "CVT" system indicates less than 0.9 V. Without CONSULT: Drive vehicle for 10 minutes. Will CONSULT be used? YES: GO TO 2. NO: GO TO 3 .
2. PERFORM IDLE AIR VOLUME LEARNING With CONSULT Perform " «WORK PROCEDURE»(ref-672625-S42429012022014112400000) ". Perform " «WORK PROCEDURE»(ref-672625-S35212184942014112400000) ". Start engine and warm it up to normal operating temperature. Select "IDLE AIR VOL LEARN" in "WORK SUPPORT" mode. Touch "START" and wait 20 seconds. Is "CMPLT" displayed on CONSULT screen? YES: GO TO 4. NO: GO TO 5.
3. PERFORM IDLE AIR VOLUME LEARNING Without CONSULT 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. Perform " «WORK PROCEDURE»(ref-672625-S42429012022014112400000) ". Perform " «WORK PROCEDURE»(ref-672625-S35212184942014112400000) ". Start engine and warm it up to normal operating temperature. Turn ignition switch OFF and wait at least 10 seconds. Confirm that accelerator pedal is fully released, turn ignition switch ON and wait 3 seconds. Repeat the following procedure quickly 5 times within 5 seconds. Fully depress the accelerator pedal. Fully release the accelerator pedal. Wait 7 seconds, fully depress the accelerator pedal for approx. 20 seconds until the MIL stops blinking and turns ON. Fully release the accelerator pedal within 3 seconds after the MIL turns ON. Start engine and let it idle. Wait 20 seconds.: GO TO 4.
4. CHECK IDLE SPEED AND IGNITION TIMING Rev up the engine 2 or 3 times and check that idle speed and ignition timing are within the specifications. For procedure, refer to " «WORK PROCEDURE»(/nissan/quest/iv-2010-2024/remont/testing-diagnostics/#engine-control-system-diagnostic-codes-symptom-tests) " and " «WORK PROCEDURE»(/nissan/quest/iv-2010-2024/remont/testing-diagnostics/#engine-control-system-diagnostic-codes-symptom-tests) ". For specifications, refer to " «IDLE SPEED»(/nissan/quest/iv-2010-2024/remont/testing-diagnostics/#engine-control-system-diagnostic-codes-symptom-tests) " and " «IGNITION TIMING»(/nissan/quest/iv-2010-2024/remont/testing-diagnostics/#engine-control-system-diagnostic-codes-symptom-tests) ". Is the inspection result normal? YES: INSPECTION END NO: GO TO 5.
5. DETECT MALFUNCTIONING PART-I 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-II 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»(/nissan/quest/iv-2010-2024/remont/testing-diagnostics/#engine-control-system-diagnostic-codes-symptom-tests) ". Refer to " «DESCRIPTION»(/nissan/quest/iv-2010-2024/remont/testing-diagnostics/#engine-control-system-diagnostic-codes-symptom-tests) ". If any of the following conditions occur after the engine has started, eliminate the cause of the incident and perform Idle Air Volume Learning again: Engine stalls. Incorrect idle. : INSPECTION END

This describes show to erase the mixture ratio self-learning value. For the actual procedure, follow the instructions in "Diagnosis Procedure".

VIN Registration is an operation to register VIN in ECM. It must be performed each time ECM is replaced.

Note. Accurate VIN which is registered in ECM may be required for Inspection & Maintenance (I/M).

See also:
• MALFUNCTION INDICATOR LAMP