Ecc Cec System Nissan Pulsar N13

DESCRIPTION

The Electronic Concentrated Engine Control System (ECCS) is a computerized emission, ignition, and fuel control system. A single Electronic Control Unit (ECU) accepts input voltage signals from a variety of input components. The ECU compares each of the voltage input signals to a preset parameter which is preprogrammed into the ECU. It instantly analyzes each of the input voltage values and adjusts output voltage signals accordingly. This allows the vehicle to perform at its optimum under a wide variety of operating conditions. All vehicles are equipped with different combinations of sensors and engine control components. (Scheme 14)and (Scheme 15). The sensors inputting information to the ECU include the following

1. Air Temperature Sensor
2. Crankshaft Angle Sensor
3. Cylinder Head Temperature Sensor
4. Detonation Sensor (Turbo Models)
5. Exhaust Gas Oxygen Sensor
6. Exhaust Gas Temperature Sensor (California Models)
7. Fuel Temperature Sensor
8. Mass Airflow Meter
9. Park/Neutral Switch
10. Power Steering Oil Pressure Switch
11. Throttle Position Switch
12. Vacuum Control Valve
13. Vehicle Speed Sensor

The ECU processes information from these input sensors and sends appropriate voltage control signals to the following engine controls

1. Airflow Meter Self-Cleaning
2. Air Induction Control Valve
3. Air Regulator Control
4. Auxiliary Air Control Valve
5. Canister Purge Valve
6. Denotation Sensor
7. EGR Control Solenoid Valve
8. Exhaust Gas Sensor Heater Control
9. Fail-Safe System
10. Fuel Injectors
11. Fuel Pressure Regulator
12. Fuel Pump Control
13. Idle Air Adjusting Unit
14. Idle Speed Control Valve
15. Idle-Up Solenoid
16. Mixture Heater
17. Mixture Ratio Feedback Control
18. Power Transistor(s) & Ignition Coil(s)
19. Pressure Regulator Control Solenoid Valve
20. Self-Diagnostics
21. Spark Plug Switching Control

ELECTRONIC CONTROL UNIT (ECU)

The ECU consists of a microcomputer, inspection lights, a diagnostic mode selector (or on/off switch), connectors and wiring for voltage signal input, voltage signal output and power supply. (Scheme 16) The unit is not serviceable and should not be opened. Monitor lights are provided on side of unit so system operation can be checked. The control unit contains memory and logic circuits that enable it to interpret sensor inputs and control various engine systems. The ECU is located under the passenger seat.

For ease of understanding, components will be grouped into 2 categories. The first being ENGINE SENSORS , components with voltage signals that are inputted into the ECU. The second being ENGINE CONTROLS , components that are controlled with voltage signals that are outputted from the ECU.

ENGINE SENSORS

Note. Vehicles do not contain all ENGINE SENSORS that are listed, nor do they control all ENGINE CONTROLS that are listed. To determine which components are in each vehicle's control system, refer to the applicable system components illustration and/or applicable wiring diagram for your vehicle application. (Scheme 14)and (Scheme 15).

Scheme 14

Scheme 15

Mass Airflow Meter

Two types of airflow meters are used. The first is a potentiometer type which uses a swinging door to measure the rate of air flow. The amount of air door movement is translated to the ECU via voltage signals. The second type measures airflow by monitoring the change of electrical resistance in the circuit that dissipates heat from the wire located in path of incoming air. The more incoming air entering through the airflow meter, the more heat removed from the hot wire. The more heat removed from hot wire the less resistance present in that circuit. The ECU evaluates the air flow rate through this change in resistance.

Crankshaft Angle Sensor

The crankshaft angle sensor monitors engine speed and piston position. The crankshaft angle sensor, which is built into the distributor, has a rotor plate and a wave-forming circuit. The rotor plate has 360 small slits, each slit determines crankshaft angle (one slit for each degree of rotation) and 4 or 6 large slits at 90 or 60 degrees each, to determine engine speed (4 slits at 90 degrees on 4 cyl., 6 slits at 60 degrees on 6 cyl.).

When the signal rotor plate passes the space between the Light Emitting Diode (LED) and photo diode, the slit in the signal rotor plate alternately cuts the light which is sent to the photo diode from the LED. This causes a pulsating voltage, which is converted into an on-off pulse by the wave-forming circuit and sent to the ECU.

Cylinder Head Temperature Sensor

A cylinder head temperature sensor is installed or built into the cylinder head near the thermostat housing. The sensor monitors changes in temperature through resistance readings of a thermistor. The thermistor, which is incorporated in the sensor, provides a varying resistance measurement as engine temperature changes. As temperature around the sensor increases, the resistance decreases.

Air Temperature Sensor

Air temperature sensors are installed in the intake air passage and sense the temperature of incoming air. A thermistor, which is sensitive to changes in temperature of incoming air, is used to increase or decrease its resistance in response to temperature rise or fall. The ECU interprets these signals and adjusts its output control signals accordingly.

Detonation (Knock) Sensor

On turbocharged vehicles, the detonation sensor is located on the engine cylinder block. The detonation sensor detects engine "knocking" and converts the "knocking" intensity into voltage signals. It sends a voltage signal to the ECU identifying how intense the "knocking" is. The control unit then modifies ignition timing accordingly to reduce detonation.

Vehicle Speed Sensor (VSS)

The vehicle speed sensor provides a vehicle speed signal to the ECU. The speed sensor consists of a reed switch, which is installed in the speedometer unit and transforms vehicle speed into a pulse signal. On digital type speedometer models, the sensor consists of an LED, photo diode, shutter and wave forming circuit. Its operating principle is the same as the crank angle sensor.

Exhaust Gas Oxygen Sensor (O2 Sensor)

This component measures the amount of unburned oxygen in the exhaust gas. It provides a voltage signal which is used to adjust air/fuel mixture (amount of injection time), so that optimum combustion can occur.

Exhaust Gas Temperature Sensor (California Models Only)

The exhaust gas temperature sensor, which is located near the EGR valve, detects the temperature of the exhaust gases passing through the EGR valve. The sensor which incorporates a thermistor, changes its resistance value in response to changes in the exhaust gas temperatures. As the temperature of the exhaust gases increase, the resistance of the sensor decreases. These changes of resistance are interpreted by the ECU and output voltage signals are modified accordingly.

Fuel Temperature Sensor

The fuel temperature sensor is built into the fuel pressure regulator and senses fuel temperature. When the fuel temperature is higher than the prespecified level, the ECU enriches the fuel being injected by increasing the injection pulse width.

Vacuum Control Valve (VCV)

The vacuum control valve is provided to reduce engine lubricating oil consumption when intake manifold vacuum increases due to very high level deceleration. The vacuum control valve senses high manifold vacuum, as vacuum increases beyond a predetermined point, the valve opens allowing air to be pulled directly into the intake manifold.

Power Steering Oil Pressure Switch

This switch is attached to the power steering high pressure line and detects the power steering load, sending a load signal to the ECU. When oil pressure exceeds a predetermined amount, the ECU will send a voltage signal to idle speed control valve to increase idle speed to assist with the power steering load.

Throttle Position Sensor (TPS) & Idle Switch

The throttle position sensor incorporates a potentiometer which varies output voltage in response to changing throttle positions. This information is relayed to the ECU in the form of input voltage signals. The TPS also has the ability to inform the ECU of the rate of speed that changes are taking place in throttle plate movement. It is attached to throttle body housing and is actuated with movement of the accelerator pedal. The idle switch, which is an integral part of the throttle position sensor, is closed at idle and open during all other conditions, this informs the ECU when the vehicle is at idle.

Fuel Injection Control

The ECU calculates base injection pulse width by processing signals from the crankshaft angle sensor and mass airflow meter. After receiving signals from each sensor that detects various engine conditions, the ECU adds fuel enrichments (which are preprogrammed into the control unit), to the base injection width. This provides the optimum mixture available throughout a wide variety of operating conditions. Fuel enrichment is always available under the following conditions: during warm-up, starting, off idle, under heavy load and when cylinder head temperature is high.

This fuel injection system incorporates mixture ratio feedback. It is designed to maintain a precise mixture ratio. Through the use of an exhaust gas sensor located in the exhaust manifold, the ECU can determine whether to enriched or lean out the air/fuel ratio to precisely control exhaust emissions and engine performance. This function takes place during closed loop operation and continuously monitors itself to stay within an acceptable emissions output range. However, this feedback system can be overridden and will operate in open loop when one or more of the following conditions exist: starting, engine and/or exhaust sensor cold, driving at high speeds or under heavy load, at idle, exhaust gas sensor monitors a too lean condition for over 10 seconds, fuel shut-off solenoid activated, exhaust gas sensor malfunctioning or pressure regulator control system in operation.

Two methods of multi-port fuel injection are used. They are simultaneous and group injection. In simultaneous injection, fuel is injected into all 4 or 6 cylinders at the same time. In group injection, the 4 or 6 injectors are divided into 2 groups and fuel is injected into each group of injectors separately. When any of the following conditions are met, fuel injection shifts from group to simultaneous: engine speed exceeds 300 RPM, cylinder head temperature is below 140°F (60°C) and during starting.

Ignition Timing Control

Ignition timing is controlled by the ECU depending upon engine operating conditions. Optimum ignition timing for each driving condition is pre-programmed into the ECU. The ECU receives electrical signals from its operating sensors which are processed within the logic circuit. After determining present driving conditions and optimum timing signal for that condition, the ECU outputs a voltage signal to the power transistor, which in turn controls timing advance or retard.

Detonation Feedback Operation

The retard system, controlled by denotation sensor, is designed exclusively for turbocharged engines. The retard system does not work under normal operating conditions. However, if engine knock occurs, the detonation sensor monitors the knocking condition and sends a signal to the ECU. After receiving the signal, the ECU retards the ignition timing to eliminate the knocking condition.

Idle Speed Control (ISC)

Engine idle speed is controlled by the ECU depending upon engine operating conditions. The ECU senses engine operating conditions and determines the best idle speed. Under any (depending upon system) of the following conditions the ECU will send an on signal to compensate idle speed: starting to 20 seconds after start, low battery voltage, headlights on, heater switch on, rear defogger on, power steering oil pressure switch on, radiator fan switch on, during deceleration and when vehicle is moving at idle. The ECU then sends a voltage signal to either the idle-up solenoid or the Auxiliary Air Control (AAC) valve (depending upon system) to either reduce or increase idle speed.

Exhaust Gas Recirculation (EGR) Control

To lower exhaust gas nitrogen oxide emissions, an exhaust gas recirculation system is incorporated within the ECCS. This is accomplished by returning a portion of exhaust gases from the exhaust manifold to the intake manifold and then to the combustion chamber to be reburned. This is controlled through the EGR valve and EGR control solenoid valve.

Under some or all of the following conditions the EGR system does not operate: engine starting, throttle valve switch on, under heavy load, low engine temperature, high engine temperature and high engine speeds. Except under the previously named conditions, when the ECU signals the EGR control solenoid, it energizes the coil within the control solenoid which pulls the plunger downward and shuts off the vacuum signal to the EGR valve.

Fuel Pump Control

Fuel pump on/off and voltage variation control is accomplished through the ECU. Depending upon the system in use, control is accomplished by either varying voltage to the fuel pump or by turning fuel pump relay on or off. Some systems incorporate the air regulator and fuel pump on and off controls simultaneously.

Fuel pump on and off control takes place as follows: ignition switch in "ON" position (operates for 5 seconds), engine running and/or cranking and engine stopped (stops in one second). Fuel pump voltage is approximately 9.4-13.4 volts except under the following conditions. Under these conditions, fuel pump voltage is approximately 13.4 volts: 5 seconds after ignition switch is turned off, during engine cranking, 30 seconds after engine starts, high engine temperature with idle switch off and low engine temperature.

Air Induction Valve (AIV) Control

The air induction system is designed to send air to exhaust manifold to reduce exhaust emissions (HC and CO). The system consists of an Air Induction Valve (AIV), AIV control valve and AIV solenoid valve. The air induction valve is designed for one-way use and consists of a one-way reed valve.

When the ECU senses a vacuum signal created by excessive exhaust pressure pulsations in the exhaust manifold, it sends a voltage signal to the AIV solenoid valve to activate the AIV control valve. The control valve opens up and allows air to enter the exhaust system upstream of the 3-way catalytic converter. This system also operates during deceleration for the purpose of blowing water off around the air injection valve.

Fuel Pressure Regulator Control

This system is designed to improve hot engine startability by cutting off intake manifold vacuum and increasing fuel pressure. When coolant temperature is above a preset limit and engine speed is lower than 2500 RPM or with a light load, the ECU sends a voltage signal to pressure regulator control solenoid valve. The electronic signal from the ECU energizes the coil inside of the pressure regulator control valve and pulls the plunger downward. This cuts off intake manifold vacuum and the positive pressure produced by pump is sent to the pressure regulator, therefore increasing fuel pressure. On some models, the fuel line is supplied with high pressure which is stored in a surge tank.

Air Regulator Control

The air regulator provides an air by-pass when engine is cold for purposes of fast idle during warm-up. A bi-metallic heater and rotary shutter valve control the rate of by-passing air. When the bi-metallic heater and shutter are cold, air by-pass port is open. As engine starts and an electrical current is permitted to flow through the bi-metallic heater, it warms up and closes the air by-pass port.

Some systems incorporate air regulator and fuel pump on and off controls simultaneously. Fuel pump and air regulator on and off control takes place as follows: ignition switch in "ON" position (operates for 5 seconds), engine running or cranking and engine stopped (stops in one second).

Auxiliary Air Control Valve (AAC)

The ECU processes signals from monitoring sensors to determine the optimum idle speed under varying engine conditions. The ECU senses engine condition and determines the best idle speed from the cylinder head temperature sensor and the transaxle gear position. It then sends an electrical on-off signal that corresponds to the difference between actual idle speed and optimum idle speed. The AAC valve then regulates the amount of by-passing air by monitoring the length of time that the electrical on signal is presented.

Airflow Meter Self-Cleaning Control

This system is designed to heat the "hot wire" of the airflow meter after ignition switch is turned to the "OFF" position. This is to clean any foreign matter that may have adhered to it during operation. After the engine has stopped, the ECU sends a signal to heat the "hot wire" to 1832°F (1000°C) to burn off any foreign material under the following conditions: if engine reached a certain predetermined RPM, vehicle speed reached a minimum MPH, coolant temperature was between 2 preset standards and only when engine is stopped by ignition key (not stalled).

Spark Plug Switching Control

The spark plug switching system is designed to change ignition system firing from 2 spark plugs to one spark plug. Normally, depending upon the system, the switching of 2 spark plugs to one takes place during heavy load driving conditions in order to reduce engine noise. Under all other conditions, a 2 spark plug ignition system is in effect.

Mixture Heater Control

The mixture heater is located between the throttle valve and the intake manifold. It is designed to atomize fuel during cold engine starts. The ECU controls the on and off cycles of the mixture heater. When the coolant temperature is less than a preset minimum and the engine is running the ECU will send an on signal to the mixture heater. The mixture heater will remain on several minutes after coolant temperature has reached the minimum temperature preset requirement.

Idle Air Adjusting (IAA) Unit

The idle air adjusting unit is a combination of the Auxiliary Air Control (AAC) valve, Fast Idle Control Device (FICD), Vacuum Control Valve (VCV) and incorporates an idle speed adjusting screw. It receives its voltage signals from the ECU to control the idle speed at predetermined amounts depending on existing operating conditions.

If airflow meter output voltage is less than or greater than the preprogrammed valve, the ECU senses an airflow meter malfunction signal. The ECU then temporarily takes its driving condition information from the throttle position sensor. During this period of time, the ECU limits the RPM of the vehicle to a preset amount. This serves to alert the vehicle driver that the vehicle is driving under fail-safe conditions and needs attention.

If the cylinder head temperature sensor circuit is open, the ECU will hold the injector pulse width to a preset amount. This preset amount is equivalent to when the cylinder head temperature is between 68°F (20°C) and 176°F (80°C), therefore allowing the vehicle to reach its destination.

Fuel Pump

Depending upon the system, if the ECU senses that the fuel pump circuit is malfunctioning, it will energize the fuel pump relay until the engine is stopped. Permitting the vehicle to reach its destination before repairing the problem.

Injector Malfunctioning

When the ECU senses that engine speed is less than a predetermined amount in the alternating injection mode (except during acceleration) and that injection pulse angle (crank angle) is less than a preset amount and at least one injector does not inject fuel 4 times in a row due to electrical problems, it determines there is an injector failure. If only one injector fails, the ECU will permit the vehicle to start and drive, but only to a predetermined maximum RPM. When the engine reaches this maximum RPM it will not go faster, indicating the fail-safe system is in effect and informing the driver that attention to the vehicle is needed.

California Models Only

All California vehicles are equipped with a "Check Engine" light located on the instrument panel. The light will illuminate when the ignition switch is turned to the "ON" position (bulb check) and when systems related to the emission controls are malfunctioning during normal operation (Mode 1) with the engine running.

Note. Under normal operation, the vehicle operates in Mode 1 of self diagnostics. If an emission control problem is detected the "Check Engine" light will illuminate. Then the ECU automatically enters Mode 2 and the "Check Engine" light will flash simultaneously with the Red LED inspection light on the ECU. The trouble codes for each malfunction can be identified by entering Mode 3 and obtaining the identification trouble code for that fault.

Depending on the vehicles control system, some or all of the following components are monitored by the "Check Engine" light function: Code 12-Mass Airflow Meter, Code 14-Vehicle Speed Sensor, Code 23-Idle Switch Circuit, Code 24-Full Throttle Switch Circuit, Code 31-Engine Control Unit (ECU), Code 32-EGR Function, Code 33 Exhaust Gas Sensor Circuit and Code 45-Injector Leakage.

The self-diagnostic system is used for diagnosing malfunctions of major sensors and actuators of the Electronic Concentrated Engine Control System (ECCS). There are 5 modes of diagnosis within the system. Before selecting any mode of self diagnosis, always perform the PRELIMINARY CHECKS first or diagnostic results and/or diagnostic time may be invalid.

Modes 1 and 2 are used for monitoring LED inspection lights which flash in accordance to the air/fuel mixture ratio. Mode 3 is used for obtaining trouble codes for component or circuit failures. Mode 4 is used to determine if malfunction(s) are present in the on/off controlled switches of the system. Mode 5 is used for monitoring the system and its components during actual driving conditions, usually to simulate an intermittent condition.

Mode 1: Mixture Ratio Feedback Control Monitor "A"

During normal vehicle operation the ECU is always in Mode 1. After warm-up and during closed loop operation, the Green LED inspection light turns on when a lean condition is detected and goes off when a rich condition is detected. During open loop operation, the Green LED light stays either on or off, which ever the light condition was just prior to switching to open loop. During open or closed loop operation, the Red inspection light stays off, with the exception of California models that have a "Check Engine" light that is illuminated on the instrument panel. See CHECK ENGINE LIGHT and MODES 1 & 2 MIXTURE RATIO MONITORS A & B.

Mode 2: Mixture Ratio Feedback Control Monitor "B"

The Green inspection light functions the same as in Mode 1. During closed loop operation, Red inspection light turns on and off simultaneously with Green inspection light when mixture ratio is being controlled correctly within the specified range. If a rich condition is detected, the Red light will remain illuminated. If a lean condition is detected, the Red light will remain off. During open loop operation, the Red inspection light is simultaneous with the Green inspection light, with the exception of California models that have a "Check Engine" light that is illuminated on the instrument panel. See CHECK ENGINE LIGHT and MODES 1 & 2 MIXTURE RATIO MONITORS A & B.

Mode 3: Self-Diagnosis

The ECU constantly monitors the operation of sensors and actuators, regardless of ignition key position. When a malfunction is suspected, the information can be retrieved from system memory by turning the diagnostic mode selector on the side of ECU to Mode 3. (Scheme 16)

When properly activated, the Red and Green LED lights will flash appropriately to signal the code number of the malfunctioning part(s). First the Red light will flash and then the Green light will follow. Red light flashes refer to number of tens in the code number. Green light flashes refer to number of ones in the code number. All codes are classified in 2 digit numbers. For example, if Red light flashes once and Green light flashes twice, code 12 is detected. All codes are stored for 50 ignition starts from the time the malfunction is last detected. A code of 55 indicates no problem in components monitored by the ECU.

When diagnostic code(s) are obtained, refer to the DRIVEABILITY/SYSTEM INSPECTION CHARTS that applies to the application of vehicle and perform the test that it refers to. If no diagnostic codes are obtained, define the driveability symptom and refer to the DRIVEABILITY/SYSTEM INSPECTION CHARTS that applies to that vehicle (perform Mode 4 first). There you will find a list of common driveability symptoms, find the symptom that your vehicle is exhibiting and check all the components in that column as well as any tests listed.

If engine cranks, but fails to start, crank engine more than 2 seconds prior to starting self-diagnosis in Mode 3. DO NOT erase stored memory codes prior to self-diagnosis (Mode 3) or intermittent malfunctions will be lost. Stored memory is lost if battery is disconnected or if Mode 4 is selected after Mode 3.

Scheme 16

Mode 4: Switches On-Off Diagnosis

During this mode the ECU monitors the performance of the components that are controlled by on/off voltage signals. The ECU will monitor switch on-off conditions and store any malfunction information in ECU memory. The switches being monitored are the throttle switch, starter switch and the vehicle speed sensor.

To test operation of the throttle switch and/or starter switch while in Mode 4 of diagnosis, observe the Red LED light on the ECU. Each time ignition switch is turned from "ON" to "OFF" position or "OFF" to "ON" position, Red LED light should blink on or off each time switching is detected.

To test the vehicle speed sensor while in Mode 4 of diagnosis, observe Green LED light of ECU. When vehicle speed is less than 12 MPH, the Green light should be off. When vehicle speed exceeds 12 MPH, Green light on ECU should illuminate.

Mode 5: Real Time Diagnosis

This mode is used to detect problems within the active system. The moment a malfunction is detected the display lights will present the malfunctioning code immediately. Making this mode of inspection advantageous because the condition can be found by observing the inspection lights during the actual driving conditions under which the malfunction intermittent or otherwise takes place.

Modes 1 & 2 Mixture Ratio Fdbk Control Monitors A & B Chart. Scheme 17

PRELIMINARY CHECKS

Note. Prior to performing any diagnostics or engine related testing, perform all preliminary tests first. Set all adjustments to specifications listed on vehicle emissions decal.

1. On all vehicles, check idle speed with automatic transmissions in "DRIVE" position (if equipped) and ensure correct idle RPM is obtained. Ensure ignition timing is set to proper specification. On Pulsar NX SE models, check idle CO to insure that it is less than 5%. Follow procedures outlined in steps 2) through 7) to check CO output.
2. Disconnect throttle switch harness connector, exhaust gas sensor connector and install a 2500 ohm resistor into the temperature sensor circuit with sensor disconnected.
3. On Pulsar NX XE models, race engine with all systems intact and immediately after engine returns to idle, confirm that both LED lights flash simultaneously in Mode 2.
4. On all models, maintain idle speed at middle engine speed (approximately 2000 RPM).
5. On Pulsar NX XE models, while in Mode 2 of diagnostics, confirm simultaneous flashes from Red and Green inspection lights. On Pulsar NX SE models, Red and Green inspection lights should flash simultaneously 9 or more times in 10 seconds while in Mode 2.
6. Perform an idle speed switch test. Idle speed should increase to the amount specified in the «IDLE SWITCH SPEED INCREASES»(/nissan/pulsar/n13-1986-1990/remont/testing-diagnostics/#ecc-cec-system) chart when idle speed switch is turned from "OFF" to "ON" position. If idle is not as specified, adjust accordingly. IDLE SWITCH SPEED INCREASES Model A/T In Neutral M/T RPM + or - Pulsar NX SE 250 250 150 Pulsar NX XE (1) (1) N/A (1) Should be in "ON" position at idle and "OFF" position when accelerator pedal is depressed.
7. Perform a test drive to evaluate the effectiveness of any adjustments that may have been made. If any driveability problems still exist, see «DRIVEABILITY/SYSTEM INSPECTION CHARTS»(/nissan/pulsar/n13-1986-1990/remont/testing-diagnostics/#ecc-cec-system) .
8. On Pulsar NX XE models, perform the Mode 3 Self-Diagnosis, then the Mode 4 Switch On/Off Test Diagnosis and a test drive to determine if intermittent problems exist. Write down any diagnostic codes may which appear.
9. On Pulsar NX SE models, perform a Mode 3 Self-Diagnosis test. Write down any diagnostic codes which appear during the Mode 3 test. A test drive to determine if any remaining problems exist.
10. If the results of the test drive are unsatisfactory (codes are presented), refer to the applicable «DRIVEABILITY/SYSTEM INSPECTION CHARTS»(/nissan/pulsar/n13-1986-1990/remont/testing-diagnostics/#ecc-cec-system) .
11. After all replacements and/or repairs are completed, test drive the vehicle to evaluate the vehicles performance after the diagnosis and repair procedure is completed.

STARTING & CHANGING MODES OF SELF-DIAGNOSIS

1. Turn ignition switch to "ON" position. Turn diagnostic mode selector of ECU fully clockwise and wait for inspection lights to begin flashing. Inspection lights will flash once indicating Mode 1, twice indicating Mode 2, etc. Count the number of flashes. Right after the number of flashes which corresponds to the diagnostic mode you with to enter appears, immediately turn the mode selector fully counterclockwise. (Scheme 16)
2. If the mode selector or mode on/off switch ("ON" position) is kept in the full clockwise position, the mode selections will continuously change. From Mode 1 to Mode 2 up to Mode 5, then it turns to Mode 1 again and the process continues. This will not erase the memory.

MEMORY ERASE

Note. If ignition switch is turned to "OFF" position in any mode of diagnosis, then turned to "ON" position after ECU has completely lost power, the diagnosis mode will automatically return to Mode 1 and begin cycling through modes again, but memory will not be erased.

Stored memory will be erased if battery is disconnected or Mode 4 is selected after Mode 3. Only if mode select switch is turned counterclockwise after Mode 3 and then after Mode 4 is selected, will stored memory be erased. However, if mode selector switch is turned fully clockwise diagnosis modes will continue to change in order until a certain mode is selected, this does not erase the stored memory.

Keys to Symbols. Scheme 18

CAUTIONS

Before connecting or disconnecting ECU harness connector to or from the ECU, be sure that ignition switch is in the "OFF" position and negative battery cable is disconnected or damage to the ECU may result. This is important because battery voltage is applied to the ECU even when the ignition switch is in the "OFF" position.

When performing an ECU input/output signal inspection, remove pin terminal retainer from connectors. This will make probing of the connector pins easier and safer.

When connecting or disconnecting pin connectors from the ECU, take care not to bend or break any pin terminals. Before replacing ECU, perform the ECU input/output signal inspection to be sure ECU is malfunctioning.

When measuring voltage supply to ECU controlled components, be sure not to touch probe testers together. Separating test probes is helpful. This will prevent accidentally making contact between the 2 probes, causing a shorted circuit and damaging the ECU.

TROUBLE CODE IDENTIFICATION CHART

Scheme 19

Driveability Inspection Tables (1 of 2). Scheme 20

Driveability Inspection Tables (2 of 2). Scheme 21

Systems Inspection Tables & Test Letter Reference Charts. Scheme 22

ECU Input/Output Volt Sig Insp Table (1 of 4) (Pulsar NX XE). Scheme 23

ECU Input/Output Volt Sig Insp Table (2 of 4) (Pulsar NX XE). Scheme 24

ECU Input/Output Volt Sig Insp Table (3 of 4) (Pulsar NX XE). Scheme 25

ECU Input/Output Volt Sig Insp Table (4 of 4) (Pulsar NX XE). Scheme 26

ECU I/O Volt Sig Insp Table (1 of 2) (Pulsar NX SE). Scheme 27

ECU I/O Volt Sig Insp Table (2 of 2) (Pulsar NX SE). Scheme 28

Crank Angle Sensor (Code 11) Test A (Exc. Pulsar NX SE). Scheme 29

Pulsar NX SE Crank Angle Sensor (Code 11) Test A. Scheme 30

Pulsar NX XE Mass Airflow Meter (Code 12) Test B. Scheme 31

Pulsar NX XE Mass Airflow Meter (Code 12) Test B. Scheme 32

Cyl Head Temp Sensor (Code 13) Test C (Exc. Pulsar NX SE). Scheme 33

Pulsar NX SE Cyl Head Temperature Sensor (Code 13) Test C. Scheme 34

Vehicle Speed Sensor (Code 14) Test D. Scheme 35

Pulsar NX SE Ign Sig & Det Sens (Codes 21 & 34) Test E (1 of 2). Scheme 36

Pulsar NX SE Ign Sig & Det Sens (Codes 21 & 34) Test E (2 of 2). Scheme 37

Pulsar NX XE Ignition Signal (Code 21) Test E. Scheme 38

Pulsar NX XE Idle Switch (Code 23) Test G. Scheme 39

Idle Switch (Code 23) Test G. Scheme 40

Pulsar NX SE Idle Switch (Code 23) Test G. Scheme 41

Pulsar NX XE Idle Speed Control Valve (Code 25) Test I. Scheme 42

Engine Control Unit Check (ECU) (Code 31) Test H. Scheme 43

Pulsar NX SE EGR Funct (CA18DE) (1 of 3) (Code 32) Test J. Scheme 44

Pulsar NX SE EGR Funct (CA18DE) (2 of 3) (Code 32) Test J. Scheme 45

Pulsar NX SE EGR Funct (CA18DE) (3 of 3) (Code 32) Test J. Scheme 46

Exhaust Gas Sensor (Code 33) Test K. Scheme 47

Pulsar NX SE Exhaust Gas Temperature Sensor (Code 35) Test L. Scheme 48

Throttle Position Sensor (Code 43) Test O (1 of 2). Scheme 49

Throttle Position Sensor (Code 43) Test O (2 of 2). Scheme 50

Pulsar NX XE Inj Malfunction (Non Self-Diag Item) Test Q. Scheme 51

Pulsar NX SE Inj Malfunction (Non Self-Diag Item) Test Q. Scheme 52

Start Signal (Switch On/Off Diagnosis) Test R. Scheme 53

Pulsar NX SE Air Regulator (Non-Diagnostic Item) Test S. Scheme 54

Pulsar NX SE Aux Air Cont Valve (Non Self-Diag Item) Test T. Scheme 55

Exc. Pulsar NX SE Power Source & Ground Ckt for ECU (Non Self-Diag Item) Test V. Scheme 56

Pulsar NX SE Power Source & Ground Ckt for ECU (Non Self Diag Item) Test V. Scheme 57

Pulsar NX XE EGR Cont & Can Purge Solenoid Cont Valve (Non Self-Diag Item) Test W. Scheme 58

Pulsar NX SE Air Inj Valve (Non Self-Diagnostic Item) Test Y. Scheme 59

Pulsar NX XE Air Inj Valve (Non Self-Diagnostic Item) Test Y. Scheme 60

Pulsar NX SE Clutch/Neutral/Inhib Sw (Non Self-Diag Items) Test Z. Scheme 61

Pulsar NX XE Clutch/Neutral/Inhibitor Switches Test Z. Scheme 62

Pulsar NX SE IAA Control (FICD) (Non Self-Diag Item) Test AA. Scheme 63

Pulsar NX XE Fuel Pump Relay (Non Self-Diag Item) Test DD. Scheme 64

Pulsar NX XE Power Valve Control (Non-Diag Item) Test FF. Scheme 65

Pulsar NX XE Mixture Heater (Non Self-Diag Item) Test HH. Scheme 66

Pulsar NX XE Mixt Htr Relay (Non Self-Diag Item) Test II. Scheme 67

Pulsar NX XE Fuel Pump (Non-Diagnostic Item) Test JJ. Scheme 68

Pulsar NX SE Fuel Pump (Non-Diagnostic Item) Test JJ. Scheme 69

Pulsar NX SE ECCS Wiring Diagram. Scheme 70

Pulsar NX XE Wiring Diagram. Scheme 71

See also:
• ENGINE SENSORS
• ENGINE CONTROLS
• PRELIMINARY CHECKS
• MEMORY ERASE