ENGINE CONTROL SYSTEM OPERATION INSPECTION [MZR 1.8, MZR 2.0, MZR 2.5]

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Input Signal System Inspection Procedure

1.  Find an irregular signal. (See Finding irregular signals.)

2.  Locate source. (See Locating the source of unusual signals.)

3.  Repair or replace the malfunctioning part.

4.  Confirm that the irregular signal is no longer detected.


Finding irregular signals

While referring to ON-BOARD DIAGNOSTIC TEST [MZR 1.8, MZR 2.0, MZR 2.5], use the PID/DATA monitor and record function to inspect the input signal system relating to the problem.

1.  Start the engine and idle the vehicle. You can assume that any signals that are out of specification by a wide margin are irregular.

2.  When recreating the problem, any sudden change in monitor input signals that is not intentionally created by the driver can be determined as irregular.


Locating the source of unusual signals

Caution
•  Compare the M-MDS monitor voltage with the measurement voltage using the digital measurement system function. If you use another tester, misreading may occur.
•  When measuring voltage, attach the tester ground to the ground of the PCM that is being tested, or to the engine itself. If this is not performed, the measured voltage and actual voltage may differ.
•  After connecting the pin to a waterproof coupler, confirming continuity and measuring the voltage, inspect the waterproof connector for cracks. If there are any, use sealant to fix them. Failure to do this may result in deterioration of the wiring harness or terminal from water damage, leading to problems with the vehicle.


Thermistor type (IAT sensor and ECT sensor)

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Input signal system inspection for thermistor type

1.  When an irregular signal is detected, measure the #1 PCM terminal voltage.

•  If the #1 terminal voltage and the M-MDS monitor voltage are the same, proceed to the next step.
•  If there is a difference of 0.5 V or more, inspect the following points concerning the PCM connector:
―  Female terminal opening loose
―  Coupler (pin holder) damage
―  Pin discoloration (blackness)
―  Harness/pin crimp is loose or disconnected

2.  Measure the #2 sensor terminal voltage.

•  If there is a 0.5 V or more difference between the sensor and the M-MDS voltages, inspect the wiring harness for open or short circuits.
•  If the sensor and the M-MDS voltages are the same, inspect the following points concerning the sensor connector:
―  Female terminal opening is loose
―  Coupler (pin holder) damage
―  Pin discoloration (blackness)
―  Harness/pin crimp is loose or disconnected
•  If there are no problems, proceed to next investigation below.


GND system inspection for thermistor type

•  Confirm that terminal sensor #3 is at 0 V.
―  If it is at 0 V, inspect the sensor. If necessary, replace the sensor.
―  If not, inspect for the following:
•  Open circuit in wiring harness
•  Female terminal opening is loose
•  Coupler (pin holder) damage
•  Pin discoloration (blackness)
•  Harness/pin crimp is loose or disconnected


Main Relay Operation Inspection

1.  Verify that the main relay clicks when the ignition is switched to ON and off.

•  If there is no operation sound, inspect the following:
―  Main relay (See RELAY INSPECTION.)
―  Harness and connector between ignition switch and main relay
―  Harness and connector between PCM terminal 1Q and main relay terminal B


Intake Manifold Vacuum Inspection

1.  Verify air intake hoses are installed properly.

2.  Start the engine and run it at idle.

3.  Disconnect the vacuum hose between the intake manifold and purge solenoid valve from the intake manifold side.

4.  Connect a vacuum gauge to the intake manifold and measure the intake manifold vacuum.

•  If not as specified, inspect the following:
Standard
MZR 1.8: −75 kPa {−563 mmHg, −22 inHg} or more
MZR 2.0: −70 kPa {−525 mmHg, −21 inHg} or more
MZR 2.5: −73.5 kPa {−551 mmHg, −21.7 inHg} or more
Note
•  Air suction can be located by engine speed change when lubricant is sprayed on the area where suction is occurring.
―  Air suction at throttle body, intake manifold and PCV valve installation points
―  EGR valve (stuck open)
―  Fuel injector insulator
―  Engine compression (See COMPRESSION INSPECTION [MZR 1.8, MZR 2.0, MZR 2.5].)


Electronic Throttle Control System Inspection


Engine coolant temperature compensation inspection

1.  Connect the M-MDS to the DLC-2.

2.  Access the following PIDs: (See ON-BOARD DIAGNOSTIC TEST [MZR 1.8, MZR 2.0, MZR 2.5].)

•  ECT
•  IAT
•  RPM

3.  Verify that the engine is cold, then start the engine.

4.  Verify that the engine speed decreases as the engine warms up.

•  If the engine speed does not decrease or decreases slowly, inspect the following:
―  ECT sensor and related wiring harness (See ENGINE COOLANT TEMPERATURE (ECT) SENSOR INSPECTION [MZR 1.8, MZR 2.0, MZR 2.5].)
―  Electronic throttle body and related wiring harness (See THROTTLE POSITION (TP) SENSOR INSPECTION [MZR 1.8, MZR 2.0, MZR 2.5].)


Load compensation inspection

1.  Start the engine and idle it.

2.  Connect the M-MDS to the DLC-2.

3.  Verify that P0506:00 or P0507:00 is not displayed.

•  If P0506:00 or P0507:00 are displayed, perform the DTC inspection. (See DTC P0506:00 [MZR 1.8, MZR 2.0, MZR 2.5].) (See DTC P0507:00 [MZR 1.8, MZR 2.0, MZR 2.5].)

4.  Access the RPM PID. (See ON-BOARD DIAGNOSTIC TEST [MZR 1.8, MZR 2.0, MZR 2.5].)

Note
•  Excludes temporary idle speed drop just after the loads are turned on.

5.  Verify that the engine speed is within the specification under each load condition.

•  If load condition is not as specified, inspect the following:
―  A/C system (A/C request signal always on or off) (See NO.23 A/C DOES NOT WORK SUFFICIENTLY [MZR 1.8, MZR 2.0, MZR 2.5].) (See NO.24 A/C IS ALWAYS ON OR A/C COMPRESSOR RUNS CONTINUOUSLY [MZR 1.8, MZR 2.0, MZR 2.5].)
―  Electrical load
―  Charging system (See BATTERY INSPECTION [MZR 1.8, MZR 2.0, MZR 2.5].) (See GENERATOR INSPECTION [MZR 1.8, MZR 2.0, MZR 2.5].)

Idle-up speed [MZR 1.8] (MTX: Neutral position)
No load: 600—700 rpm
A/C on and refrigerant pressure switch (middle pressure) is off: 700—800 rpm
A/C on and refrigerant pressure switch (middle pressure) is on: 700—800 rpm
Electrical loads on: 650—750 rpm
Idle-up speed [MZR 2.0] (ATX: P, N position, MTX: Neutral position)
No load: 650—750 rpm (ATX), 600—700 rpm (MTX)
A/C on and refrigerant pressure switch (middle pressure) is off: 700—800 rpm
A/C on and refrigerant pressure switch (middle pressure) is on: 700—800 rpm
Electrical loads on: 650—750 rpm
Idle-up speed [MZR 2.5] (ATX: P, N position, MTX: Neutral position)
No load: 600—700 rpm
A/C on and refrigerant pressure switch (middle pressure) is off: 650—750 rpm
A/C on and refrigerant pressure switch (middle pressure) is on: 700—800 rpm
Electrical loads on: 600—750 rpm (ATX), 650—750 rpm (MTX)


Throttle position (TP) sweep inspection

1.  Connect the M-MDS to the DLC-2.

2.  Switch the ignition to ON.

3.  Verify that none of the following DTC are displayed:

•  P0122:00, P0123:00, P0222:00, P0223:00, P0638:00, P2100:00, P2101:00, P2107:00, P2108:00, P2119:00, P2122:00, P2123:00, P2127:00, P2128:00, P2135:00, P2138:00
―  If any one DTC is displayed, perform the DTC inspection. (See DTC TABLE [MZR 1.8, MZR 2.0, MZR 2.5].)

4.  Access the TP_REL PID.

5.  Verify that the PID reading is within the TP_REL value. (See PCM INSPECTION [MZR 1.8, MZR 2.0, MZR 2.5].)

•  If the PID reading is out of range, perform the following:
―  Remove the air duct from the throttle body.
―  Verify that the throttle valve opens when the accelerator pedal is depressed.
•  If the throttle valve opens, inspect the TP sensor and related wiring harness.
•  If the throttle valve does not open, inspect the throttle actuator control motor and related wiring harness.

6.  Gradually depress the throttle pedal and verify that the PID reading increases accordingly.

•  If the PID reading drops momentarily, inspect the following:
―  TP sensor

7.  Fully depress the throttle pedal and verify that the PID reading is within WOT value. (See PCM INSPECTION [MZR 1.8, MZR 2.0, MZR 2.5].)

•  If the PID reading is out of range, perform the followings:
―  Remove the air duct from throttle body.
―  Verify that the throttle valve opens when throttle pedal is depressed.
•  If the throttle valve opens, inspect the TP sensor and related wiring harness.
•  If the throttle valve does not open, inspect the throttle actuator control motor and related wiring harness.


Brake override system operation inspection (GH1***-429761,GH1***-442043,GH10**-206766,GH10**-210449,GH****-210421)

Note
•  If the brake override system operates normally after performing the following inspection, the PCM detects DTC P2299:00.

1.  Start the engine and run it is idling.

2.  Verify that the engine speed becomes approx. 1,200 rpm under the following conditions.

•  Neutral (MTX)
•  P, or N position (ATX)
•  Engine speed of 1,150 rpm or more other than idle
•  Brake pedal depressed
―  If the engine speed becomes approx. 1,200 rpm, clear the PCM DTC using the M-MDS. (System operation is normal.)
―  If the engine speed does not become approx. 1,200 rpm, inspect for the following parts, then repair or replace the malfunctioning part:
•  APP sensor (See ACCELERATOR PEDAL POSITION (APP) SENSOR INSPECTION [MZR 1.8, MZR 2.0, MZR 2.5].)
•  Neutral switch (MTX) (See NEUTRAL SWITCH INSPECTION [MZR 1.8, MZR 2.0, MZR 2.5].)
•  Clutch switch (MTX) (See CLUTCH PEDAL POSITION (CPP) SWITCH INSPECTION [MZR 1.8, MZR 2.0, MZR 2.5].)
•  TR switch (ATX) (See TRANSAXLE RANGE (TR) SWITCH INSPECTION [FS5A-EL].)
•  Brake switch No.1 (See BRAKE SWITCH INSPECTION.)
•  Brake switch No.2 (See BRAKE SWITCH INSPECTION.)
•  Communication between PCM and TCM (ATX) (See FOREWORD [MULTIPLEX COMMUNICATION SYSTEM (L.H.D. (EXCEPT MZR-CD 2.2, MZR 2.0 DISI))].) (See FOREWORD [MULTIPLEX COMMUNICATION SYSTEM (R.H.D. (EXCEPT MZR-CD 2.2, MZR 2.0 DISI))].)


Variable Intake Air Control Operation Inspection

1.  Start the engine.

2.  Inspect the rod operation under the following condition:

Rod operation

Engine speed
4,400 rpm
Below
Above
Shutter valve actuator
Operate
Not operate

•  If the rod operation is not as specified, inspect as follows:
(1)  Stop the engine.
(2)  Connect the M-MDS to the DLC-2.
(3)  Verify that DTC P0661:00 or P0662:00 is not displayed.
•  If DTC P0661:00 or P0662:00 is shown, perform the DTC inspection. (See DTC P0661:00 [MZR 1.8, MZR 2.0, MZR 2.5].) (See DTC P0662:00 [MZR 1.8, MZR 2.0, MZR 2.5].)
(4)  Inspect the variable intake air solenoid valve. (See VARIABLE INTAKE AIR SOLENOID VALVE INSPECTION [MZR 2.0, MZR 2.5].)
•  If the variable intake air solenoid valve is not normal, replace the variable intake air solenoid valve. (See INTAKE-AIR SYSTEM REMOVAL/INSTALLATION [MZR 1.8, MZR 2.0, MZR 2.5].)
•  If the variable intake air solenoid valve is normal, inspect the following:
―  Vacuum hose and vacuum chamber for looseness or damage
―  Shutter valve actuator (See VARIABLE INTAKE AIR SHUTTER VALVE ACTUATOR INSPECTION [MZR 2.0, MZR 2.5].)
―  Shutter valve stuck open or closed


Variable Tumble Control Operation Inspection

1.  Connect the M-MDS to the DLC-2.

2.  Access the ECT PID. (See ON-BOARD DIAGNOSTIC TEST [MZR 1.8, MZR 2.0, MZR 2.5].)

3.  Verify that ECT PID is less than 60 °C {140 °F}.

4.  Start the engine.

5.  Inspect rod operation under the following conditions:

Rod operation

Engine speed
3,750 rpm
Below
Above
Shutter valve actuator
Operate
Not operate

•  If the rod operation is not specified, inspect as follows:
(1)  Verify that DTC P2009:00 or P2010:00 is not displayed.
•  If DTC No. P2009:00 or P2010:00 are shown, perform the DTC inspection. (See DTC P2009:00 [MZR 1.8, MZR 2.0, MZR 2.5].) (See DTC P2010:00 [MZR 1.8, MZR 2.0, MZR 2.5].)
(2)  Inspect the variable tumble solenoid valve. (See VARIABLE TUMBLE SOLENOID VALVE INSPECTION [MZR 1.8, MZR 2.0, MZR 2.5].)
•  If the variable tumble solenoid valve is not normal, replace the variable tumble solenoid valve. (See INTAKE-AIR SYSTEM REMOVAL/INSTALLATION [MZR 1.8, MZR 2.0, MZR 2.5].)
•  If the variable tumble solenoid valve is normal, inspect the following:
―  Vacuum hose and vacuum chamber for looseness or damage
―  Shutter valve actuator (See VARIABLE TUMBLE SHUTTER VALVE ACTUATOR INSPECTION [MZR 1.8, MZR 2.0, MZR 2.5].)
―  Shutter valve stuck open or closed


Fuel Injector Operation Inspection

If simulation function of M-MDS is used:

STEP

INSPECTION

RESULTS

ACTION
1
Start the engine and warm it up until normal operating temperature.
Access the INJ_1, INJ_2, INJ_3 and INJ_4 PIDs using the M-MDS.
(See ON-BOARD DIAGNOSTIC TEST [MZR 1.8, MZR 2.0, MZR 2.5].)
Turn the fuel injector from on to off using the PIDs each cylinder.
Does the engine speed drop?
Yes
Fuel injector work properly.
No
Go to the next step.
2
Disconnect the fuel injector that the engine speed does not drop at Step 1.
Switch the ignition to ON (engine off).
Measure the voltage at the suspected fuel injector terminal B (wiring harness-side).
Is the voltage B+?
Yes
Go to the next step.
No
Repair or replace the wiring harness for a possible open or short circuit.
3
Inspect for open or short circuit between the following terminals (wiring harness-side):
•  Fuel injector No.1 terminal A—PCM terminal 2BB
•  Fuel injector No.2 terminal A—PCM terminal 2BC
•  Fuel injector No.3 terminal A—PCM terminal 2BD
•  Fuel injector No.4 terminal A—PCM terminal 2AZ
Is there any malfunction?
Yes
Repair or replace the wiring harness for a possible open or short circuit.
No
Go to the next step.
4
Inspect the suspected fuel injector.
(See FUEL INJECTOR INSPECTION [MZR 1.8, MZR 2.0, MZR 2.5].)
Is there any malfunction?
Yes
Replace the suspected fuel injector.
(See FUEL INJECTOR REMOVAL/INSTALLATION [MZR 1.8, MZR 2.0, MZR 2.5].)
No
Replace the PCM.
(See PCM REMOVAL/INSTALLATION [MZR 1.8, MZR 2.0, MZR 2.5].)

If simulation function of M-MDS is used:

STEP

INSPECTION

RESULTS

ACTION
1
While cranking the engine, inspect for fuel injector operation sound at each cylinder using a soundscope.
Is the operation sound heard?
Yes
Fuel injector work properly.
No
Go to the next step.
2
Disconnect the fuel injector that the engine speed does not drop at Step 1.
Switch the ignition to ON (engine off).
Measure the voltage at the suspected fuel injector terminal B (wiring harness-side).
Is the voltage B+?
Yes
Go to the next step.
No
Repair or replace the wiring harness for a possible open or short circuit.
3
Inspect for open or short circuit between the following terminals (wiring harness-side):
•  Fuel injector No.1 terminal A—PCM terminal 2BB
•  Fuel injector No.2 terminal A—PCM terminal 2BC
•  Fuel injector No.3 terminal A—PCM terminal 2BD
•  Fuel injector No.4 terminal A—PCM terminal 2AZ
Is there any malfunction?
Yes
Repair or replace the wiring harness for a possible open or short circuit.
No
Go to the next step.
4
Inspect the suspected fuel injector.
(See FUEL INJECTOR INSPECTION [MZR 1.8, MZR 2.0, MZR 2.5].)
Is there any malfunction?
Yes
Replace the suspected fuel injector.
(See FUEL INJECTOR REMOVAL/INSTALLATION [MZR 1.8, MZR 2.0, MZR 2.5].)
No
Replace the PCM.
(See PCM REMOVAL/INSTALLATION [MZR 1.8, MZR 2.0, MZR 2.5].)


Fuel Cut Control System Inspection

1.  Warm up engine and idle it.

2.  Turn off the electrical loads and A/C switch.

3.  Connect the M-MDS to the DLC-2.

4.  Access the RPM PID.

5.  Listen for the fuel injector operation sound at all cylinders using the soundscope and monitor both PIDs while performing the following steps:

(1)  Depress the accelerator pedal and increase the engine speed to 4,000 rpm.
(2)  Quickly release the accelerator pedal (brake pedal is not depressed) and verify that the fuel injector operation sound stops, and starts again when the engine speed drops below 1,200 rpm.
•  If not as specified, inspect the following:
―  ECT sensor and related wiring harness (See ENGINE COOLANT TEMPERATURE (ECT) SENSOR INSPECTION [MZR 1.8, MZR 2.0, MZR 2.5].)
―  TR switch and related wiring harness (See TRANSAXLE RANGE (TR) SWITCH INSTALLATION [FS5A-EL].)


Fuel Pump Operation Inspection

1.  Remove the fuel-filler cap.

2.  Switch the ignition to ON.

3.  Turn the fuel pump relay from off to on using the FP PID and inspect if the operation sound is heard.

•  If no operation sounds is heard, proceed to next step.

4.  Measure the voltage at wiring harness side fuel pump connector terminal B

Specification
B+ (Ignition at on)
•  If the voltage is as specified, inspect the following:
―  Fuel pump continuity
―  Fuel pump GND
―  Wiring harness between fuel pump relay terminal E and PCM terminal 1BG
•  If not as specified, inspect the following:
―  Fuel pump relay (See RELAY INSPECTION.)
―  Wiring harness connector (Battery—Fuel pump relay—Fuel pump)


Fuel Pump Control System Inspection

1.  Crank the engine and verify that fuel pump relay operation sound is heard.

2.  If operation sound is not heard, inspect the following:

•  Fuel pump relay (See RELAY INSPECTION.)
•  Wiring harness and connectors (Battery—Fuel pump relay terminal E—PCM terminal 1BG


Spark Test

1.  Disconnect the fuel pump relay.

2.  Verify that each ignition coil and connector is connected properly.

3.  Inspect the ignition system in the following procedure.

Warning
•  High voltage in the ignition system can cause strong electrical shock which can result in serious injury. Avoid direct contact to the vehicle body during the following spark test.

STEP

INSPECTION

ACTION
1
Disconnect the ignition coil from the spark plugs.
Remove the spark plugs.
(See SPARK PLUG REMOVAL/INSTALLATION [MZR 1.8, MZR 2.0, MZR 2.5].)
Verify that the spark plugs do not have carbon deposits.
Is there any malfunction?
Yes
Perform no-load racing at 4,000 rpm for 2 min, 2 times to burn off the carbon deposits.
Repeat Step 1.
No
Go to the next step.
2
Inspect the spark plugs for damage, wear, and proper plug gap.
Is there any malfunction?
Yes
Replace the spark plugs, then go to Step 1.
(See SPARK PLUG REMOVAL/INSTALLATION [MZR 1.8, MZR 2.0, MZR 2.5].)
No
Go to the next step.
3
Reconnect the spark plugs to the ignition coil.
Ground the spark plugs to the engine.
Is a strong blue spark visible at each cylinder while cranking the engine?
Yes
Ignition system is normal.
No
Some cylinders do not spark:
•  Go to the next step.
All cylinders do not spark:
•  Go to Step 5.
4
Inspect for open or short circuit between the following terminals (wiring harness-side):
•  Ignition coil No.1 terminal C—PCM terminal 2G
•  Ignition coil No.2 terminal C—PCM terminal 2K
•  Ignition coil No.3 terminal C—PCM terminal 2L
•  Ignition coil No.4 terminal C—PCM terminal 2H
Is there any malfunction?
Yes
Repair or replace the suspected wiring harness, then go to Step 1.
No
Inspect and replace the ignition coil, then go to Step 1.
(See IGNITION COIL INSPECTION [MZR 1.8, MZR 2.0, MZR 2.5].)
(See IGNITION COIL REMOVAL/INSTALLATION [MZR 1.8, MZR 2.0, MZR 2.5].)
5
Switch the ignition to ON (engine off).
Measure the voltage at the terminal A (wiring harness-side) in each ignition coils.
Is the voltage B+?
Yes
Go to the next step.
No
Inspect the power supply circuit of ignition coils.
Repair or replace the suspected wiring harness, then go to Step 1.
6
Inspect the PCM and ignition coil connector or terminals for poor connection.
Is there any malfunction?
Yes
Repair or replace the malfunctioning connector and/or terminals, then go to Step 1.
No
Go to the next step.
7
Inspect the CKP sensor and crankshaft pulley.
(See CRANKSHAFT POSITION (CKP) SENSOR INSPECTION [MZR 1.8, MZR 2.0, MZR 2.5].)
Is there any malfunction?
Yes
Repair or replace the malfunctioning part according to the inspection results, then go to Step 1.
No
Inspect for open or short circuit in wiring harness and connector of CKP sensor.
Repair or replace the malfunctioning part according to the inspection results, then go to Step 1.


EGR Control System Inspection

1.  Crank the engine and verify that EGR valve operation (initial operation) sound is heard.

•  If the operation sound is not heard, connect the M-MDS to the DLC-2 and verify that the DTC P0403:00 is shown. Perform the DTC inspection. (See DTC P0403:00 [MZR 1.8, MZR 2.0, MZR 2.5].)

2.  Start the engine and idle it.

3.  Increase the step value of the EGR valve from 0 to 40 using the SEGRP PID of the simulation function.

4.  Operate the EGR valve and inspect if the engine speed becomes unstable or the engine stalls.

•  If the engine speed does not change, proceed to the following.
(1)  Stop the engine.
(2)  Remove the EGR valve. (See EGR VALVE REMOVAL/INSTALLATION [MZR 1.8, MZR 2.0, MZR 2.5].)
(3)  Connect the EGR valve connector.
(4)  Switch the ignition to ON (engine off).
(5)  Increase the step value of EGR valve from 0 to 40 using the SEGRP PID.
(6)  Verify that the EGR valve operates according to the SEGRP PID.
•  If the EGR valve is operated, clean the EGR valve and reinspect from Step 2.
•  If the EGR valve does not operate, replace the EGR valve and reinspect from Step 2.

5.  Warm up the engine to normal operating temperature.

6.  Access the following PIDs: (See ON-BOARD DIAGNOSTIC TEST [MZR 1.8, MZR 2.0, MZR 2.5].)

•  APP1
•  APP2
•  ECT
•  RPM
•  SEGRP_DSD
•  VSS

7.  Idle the vehicle and verify that the SEGRP value is 0.

Caution
•  While performing the this step, always operate the vehicle in a safe and lawful manner.
•  When the M-MDS is used to observe monitor system status while driving, be sure to have another technician with you, or record the data in the M-MDS using the PID/DATA MONITOR AND RECORD capturing function and inspect later.

8.  Put the vehicle in drive.

9.  Depress the accelerator pedal and verify that the SEGRP_DSD value is increased.

•  If the EGR valve increases, inspect the following:
―  EGR valve (stuck open or close) (See EGR VALVE INSPECTION [MZR 1.8, MZR 2.0, MZR 2.5].)
―  Wiring harness and connectors (Main relay—EGR valve—PCM)
•  If the SEGRP_DSD value does not increase, inspect the VSS, APP1, APP2, TP_REL and ECT PIDs. (See PCM INSPECTION [MZR 1.8, MZR 2.0, MZR 2.5].)

10.  Stop the vehicle and verify that the SEGRP value returns to 0.


Purge Control System Inspection

1.  Start the engine.

2.  Disconnect the vacuum hose between the purge solenoid valve and the charcoal canister.

3.  Put a finger to the purge solenoid valve and verify that there is no vacuum applied when the engine is cold.

•  If there is a vacuum, inspect the following:
―  Wiring harness and connectors (Purge solenoid valve terminal A—PCM terminal 2C)
―  Purge solenoid valve (See PURGE SOLENOID VALVE INSPECTION [MZR 1.8, MZR 2.0, MZR 2.5].)

4.  Warm up the engine to the normal operating temperature.

5.  Stop the engine.

6.  Connect the M-MDS to the DLC-2 and verify that the DTC P0443:00 is shown. Perform the DTC inspection. (See DTC P0443:00 [MZR 1.8, MZR 2.0, MZR 2.5].)

7.  Switch the ignition to ON.

8.  Access the ECT PID. (See ON-BOARD DIAGNOSTIC TEST [MZR 1.8, MZR 2.0, MZR 2.5].)

9.  Verify that the engine coolant temperature is more than 60 °C {140 °F}.

•  If the M-MDS indicates less than 60 °C {140 °F}, perform the ECT sensor inspection. (See ENGINE COOLANT TEMPERATURE (ECT) SENSOR INSPECTION [MZR 1.8, MZR 2.0, MZR 2.5].)

10.  Set the vehicle on the dynamometer or chassis roller.

Warning
•  When the dynamometer or chassis roller is operating, there is a possibility that the operator may come into contact with or be caught up in the rotating parts, leading to serious injuries or death. When performing work while the dynamometer or chassis roller is operating, be careful not to come into contact with or be caught up in any of the rotating parts.

11.  Drive vehicle at engine speed approx. 2,000 rpm for 30 s or more.

12.  Put a finger to the purge solenoid valve and verify that there is no vacuum applied while step 2.

•  If there is no vacuum, inspect the following:
―  Wiring harness and connector (Main relay—Purge solenoid valve—PCM terminal 2C)
―  Purge solenoid valve (See PURGE SOLENOID VALVE INSPECTION [MZR 1.8, MZR 2.0, MZR 2.5].)
―  MAF, APP1, APP2, TP_REL and LOAD PIDs (See PCM INSPECTION [MZR 1.8, MZR 2.0, MZR 2.5].)
•  If there is vacuum, inspect the following:
―  Vacuum hose (Purge solenoid valve—Charcoal canister)


A/C Cut-off Control System Inspection

1.  Start the engine.

2.  Turn the A/C switch and the fan switch on.

3.  Verify that the A/C compressor magnetic clutch actuates.

•  If it does not actuate, go to symptom troubleshooting “NO.23 A/C DOES NOT WORK SUFFICIENTLY“. (See NO.23 A/C DOES NOT WORK SUFFICIENTLY [MZR 1.8, MZR 2.0, MZR 2.5].)

4.  Fully open the throttle valve and verify that the A/C compressor magnetic clutch does not actuate for 2—5 s.

•  If it actuates, inspect as follows:
―  A/C relay (See RELAY INSPECTION.)
―  Open or short to ground circuit in wiring harness and connectors (Ignition switch—A/C relay—PCM terminal 1I)
―  A/C related parts
―  APP1, APP2 PIDs (See PCM INSPECTION [MZR 1.8, MZR 2.0, MZR 2.5].)


Cooling Fan Control System Inspection

Note
•  There are four types of cooling fan components, A, B, C, and D. Types A, B, C, and D can be identified from the number of blades and fan motor connector terminals on the cooling fans No. 1 and No. 2. Refer to the following table to identify the cooling fan type.

Cooling fan components

Number of blades

Number of fan motor connector terminals

Cooling fan No.1

Cooling fan No.2

Fan motor No.1

Fan motor No.2
Type A
5
7
2
2
Type B
5
7
4
4
Type C
7
5
2
2
Type D
11
9
4
4


Type A

1.  Connect the M-MDS to the DLC-2.

2.  Perform the KOEO or KOER self test and verify that DTCs P0117:00, P0118:00, P0480:00 and/or P0481:00 are not shown using the KOEO and/or KOER self test. (See KOEO/KOER SELF TEST [MZR 1.8, MZR 2.0, MZR 2.5].)

•  If DTCs P0117:00, P0118:00, P0480:00 and/or P0481:00 are shown, perform the applicable DTC troubleshooting procedure. (See DTC P0117:00 [MZR 1.8, MZR 2.0, MZR 2.5].) (See DTC P0118:00 [MZR 1.8, MZR 2.0, MZR 2.5].) (See DTC P0480:00 [MZR 1.8, MZR 2.0, MZR 2.5].) (See DTC P0481:00 [MZR 1.8, MZR 2.0, MZR 2.5].)

3.  Start the engine and let it at idle with ECT is below 97 °C {207 °F}.

4.  Verify that the cooling fans are not operating when A/C switch and fan switch are turned off.

•  If the cooling fan is operating, inspect for the following based on cooling fans status:

Cooling fan status

Inspection item

Cooling fan No.1

Cooling fan No.2
Operate
Operate
•  Wiring harness between refrigerant pressure switch (low, high) and PCM terminal 1AW (Short to ground) (PCM PID AC_REQ is always ON)
Operate
Stop
•  Cooling fan relay No.1 (Stuck close)
•  Wiring harness in cooling fan relay No.1—cooling fan No.1 (Short to power supply circuit)
Stop
Operate
•  Cooling fan relay No.2 (Stuck close)
•  Wiring harness in cooling fan relay No.2—cooling fan No.2 (Short to power supply circuit)

5.  Using the M-MDS simulation function, turn FAN1 from the off position to the ON position, and verify that cooling fan No.1 operates.

•  If the operation could not be confirmed, inspect for the following based on cooling fans status:

Cooling fan status

Inspection item

Cooling fan No.1

Cooling fan No.2
Stop
Stop
•  Cooling fan relay No.1 (Stuck open)
•  Wiring harness in battery—cooling fan relay No.1—cooling fan No.1 (Open circuit, Fuse is melt by short to ground)
•  Wiring harness in cooling fan No.1—body ground (Open circuit)

6.  Using the M-MDS simulation function, turn FAN1 and FAN2 from the off position to the ON position, and verify that cooling fans No.1 and No.2 operate.

•  If the operation could not be confirmed, inspect for the following based on cooling fans status:

Cooling fan status

Inspection item

Cooling fan No.1

Cooling fan No.2
Operate
Stop
•  Cooling fan relay No.2 (Stuck open)
•  Wiring harness in battery—cooling fan relay No.2—cooling fan No.2 (Open circuit, Fuse is melt by short to ground)
•  Wiring harness in cooling fan No.2—body ground (Open circuit)


Type B

1.  Connect the M-MDS to the DLC-2.

2.  Perform the KOEO or KOER self test and verify that DTCs P0117:00, P0118:00, P0480:00, P0481:00 and/or P0482:00 are not shown using the KOEO and/or KOER self test. (See KOEO/KOER SELF TEST [MZR 1.8, MZR 2.0, MZR 2.5].)

•  If DTCs P0117:00, P0118:00, P0480:00, P0481:00 and/or P0482:00 are shown, perform the applicable DTC troubleshooting procedure. (See DTC P0117:00 [MZR 1.8, MZR 2.0, MZR 2.5].) (See DTC P0118:00 [MZR 1.8, MZR 2.0, MZR 2.5].) (See DTC P0480:00 [MZR 1.8, MZR 2.0, MZR 2.5].) (See DTC P0481:00 [MZR 1.8, MZR 2.0, MZR 2.5].) (See DTC P0482:00 [MZR 1.8, MZR 2.0, MZR 2.5].)

3.  Start the engine and let it at idle with ECT is below 97 °C {207 °F}.

4.  Verify that the cooling fans are not operating when A/C switch and fan switch are turned off.

•  If the cooling fan is operating, inspect for the following based on cooling fans status:

Cooling fan status

Inspection item

Cooling fan No.1

Cooling fan No.2
Low
Stop
•  Cooling fan relay No.1 (Stuck close)
Low
Low
•  Cooling fan relay No.3 (Stuck close)
•  Wiring harness between refrigerant pressure switch (low, high) and PCM terminal 1AW (Short to ground) (PCM PID AC_REQ is always ON)
Stop
Low
•  Cooling fan relay No.4 (Stuck close)
High
Low
•  Wiring harness between refrigerant pressure switch (low, high) and PCM terminal 1AW (Short to ground) (PCM PID AC_REQ is always ON)

5.  Using the M-MDS simulation function, turn FAN1 and FAN3 from the off position to the ON position, and verify that cooling fans No.1 and No.2 operate at low speed.

•  If the operation could not be confirmed, inspect for the following based on cooling fans status:

Cooling fan status

Inspection item

Cooling fan No.1

Cooling fan No.2
Stop
Low
•  Cooling fan relay No.1 (Stuck open)
•  Wiring harness in battery—cooling fan relay No.1—cooling fan No.1 (Open circuit, Fuse is melt by short to ground)
•  Wiring harness in cooling fan No.1—body ground (Open circuit)
•  Cooling fan No.1 (Internal circuit open)
Low
Stop
•  Cooling fan relay No.4 (Stuck open)
•  Wiring harness in battery—cooling fan relay No.4—cooling fan No.2 (Open circuit, Fuse is melt by short to ground)
•  Wiring harness in cooling fan No.2—body ground (Open circuit)
•  Cooling fan No.2 (Internal circuit open)

6.  Using the M-MDS simulation function, turn FAN1 and FAN2 from the off position to the ON position, and verify that cooling fan No.1 operates at high speed and cooling fan No.2 operates at low speed.

•  If the operation could not be confirmed, inspect for the following based on cooling fans status:

Cooling fan status

Inspection item

Cooling fan No.1

Cooling fan No.2
High
Stop
•  Wiring harness in cooling fan relay No.3—cooling fan No.2 (Open circuit)
•  Cooling fan No.2 (Internal circuit open)
Low
Stop
•  Cooling fan relay No.3 (Stuck open)
•  Wiring harness in battery—cooling fan relay No.3 (Open circuit, Fuse is melt by short to ground)
•  Wiring harness in cooling fan relay No.3—cooling fan No.1 (Fuse is melt by short to ground)
•  Wiring harness in cooling fan relay No.3—cooling fan No.2 (Fuse is melt by short to ground)
Low
Low
•  Cooling fan relay No.2 (Stuck open)
•  Wiring harness in cooling fan No.1—cooling fan relay No.2—body ground (Open circuit)
•  Wiring harness in cooling fan relay No.3—cooling fan No.1 (Open circuit)
•  Cooling fan No.1 (Internal circuit open)

7.  Using the M-MDS simulation function, turn FAN1, FAN2, and FAN3 from the off position to the ON position, and verify that cooling fans No.1 and No.2 operate at high speed.

•  If the operation could not be confirmed, inspect for the following based on cooling fans status:

Cooling fan status

Inspection item

Cooling fan No.1

Cooling fan No.2
High
Low
•  Wiring harness in cooling fan No.2—cooling fan relay No.2 (Open circuit)
•  Cooling fan No.2 (Internal circuit open)


Type C

1.  Connect the M-MDS to the DLC-2.

2.  Perform the KOEO or KOER self test and verify that DTCs P0117:00, P0118:00, P0480:00 and/or P0481:00 are not shown using the KOEO and/or KOER self test. (See KOEO/KOER SELF TEST [MZR 1.8, MZR 2.0, MZR 2.5].)

•  If DTCs P0117:00, P0118:00, P0480:00 and/or P0481:00 are shown, perform the applicable DTC troubleshooting procedure. (See DTC P0117:00 [MZR 1.8, MZR 2.0, MZR 2.5].) (See DTC P0118:00 [MZR 1.8, MZR 2.0, MZR 2.5].) (See DTC P0480:00 [MZR 1.8, MZR 2.0, MZR 2.5].) (See DTC P0481:00 [MZR 1.8, MZR 2.0, MZR 2.5].)

3.  Start the engine and let it at idle with ECT is below 97 °C {207 °F}.

4.  Verify that the cooling fans are not operating when A/C switch and fan switch are turned off.

•  If the cooling fan is operating, inspect for the following based on cooling fans status:

Cooling fan status

Inspection item

Cooling fan No.1

Cooling fan No.2
Low
Low
•  Cooling fan relay No.1 (Stuck close)
High
High
•  Wiring harness between refrigerant pressure switch (low, high) and PCM terminal 1AW (Short to ground) (PCM PID AC_REQ is always ON)
Stop
High
•  Cooling fan relay No.3 (Stuck close)

5.  Using the M-MDS simulation function, turn FAN1 from the off position to the ON position, and verify that cooling fans No.1 and No.2 operate at low speed.

•  If the operation could not be confirmed, inspect for the following based on cooling fans status:

Cooling fan status

Inspection item

Cooling fan No.1

Cooling fan No.2
Stop
Stop
•  Cooling fan relay No.1 (Stuck open)
•  Cooling fan No.1 (Internal circuit open)
•  Cooling fan No.2 (Internal circuit open)
•  Wiring harness in battery—cooling fan relay No.1—cooling fan No.1 (Open circuit, Fuse is melt by short to ground)
•  Wiring harness in cooling fan No.1—cooling fan relay No.3—cooling fan No.2 (Open circuit)
•  Wiring harness in cooling fan No.2—body ground (Open circuit)
High
Stop
•  Cooling fan relay No.2 (Stuck close)
•  Wiring harness in cooling fan No.1—cooling fan relay No.3—cooling fan No.2 (Short to ground)*

*  :The fuse between the battery and cooling fan relay No.3 may be burnt out.

6.  Using the M-MDS simulation function, turn FAN1 and FAN2 from the off position to the ON position, and verify that cooling fans No.1 and No.2 operate at high speed.

•  If the operation could not be confirmed, inspect for the following based on cooling fans status:

Cooling fan status

Inspection item

Cooling fan No.1

Cooling fan No.2
Stop
High
•  Cooling fan relay No.2 (Stuck open)
•  Wiring harness in cooling fan relay No.2—body ground (Open circuit)
High
Stop
•  Cooling fan relay No.3 (Stuck open)
•  Wiring harness in battery—cooling fan relay No.3 (Open circuit, Fuse is melt by short to ground)


Type D

1.  Connect the M-MDS to the DLC-2.

2.  Perform the KOEO or KOER self test and verify that DTCs P0117:00, P0118:00, P0480:00, P0481:00 and/or P0482:00 are not shown using the KOEO and/or KOER self test. (See KOEO/KOER SELF TEST [MZR 1.8, MZR 2.0, MZR 2.5].)

•  If DTCs P0117:00, P0118:00, P0480:00, P0481:00 and/or P0482:00 are shown, perform the applicable DTC troubleshooting procedure. (See DTC P0117:00 [MZR 1.8, MZR 2.0, MZR 2.5].) (See DTC P0118:00 [MZR 1.8, MZR 2.0, MZR 2.5].) (See DTC P0480:00 [MZR 1.8, MZR 2.0, MZR 2.5].) (See DTC P0481:00 [MZR 1.8, MZR 2.0, MZR 2.5].) (See DTC P0482:00 [MZR 1.8, MZR 2.0, MZR 2.5].)

3.  Start the engine and let it at idle with ECT is below 97 °C {207 °F}.

4.  Verify that the cooling fans are not operating when A/C switch and fan switch are turned off.

•  If the cooling fan is operating, inspect for the following based on cooling fans status:

Cooling fan status

Inspection item

Cooling fan No.1

Cooling fan No.2
Low
Stop
•  Cooling fan relay No.1 (Stuck close)
•  Wiring harness in cooling fan relay No.1—cooling fan No.1 (Short to power supply circuit)
Stop
Low
•  Cooling fan relay No.4 (Stuck close)
•  Wiring harness in cooling fan relay No.4—cooling fan No.1 (Short to power supply circuit)
Low
Low
•  Wiring harness between refrigerant pressure switch (low, high) and PCM terminal 1AW (Short to ground) (PCM PID AC_REQ is always ON)
High
Middle
•  Wiring harness between refrigerant pressure switch (low, high) and PCM terminal 1AW (Short to ground) (PCM PID AC_REQ is always ON)

5.  Using the M-MDS simulation function, turn FAN1 and FAN3 from the off position to the ON position, and verify that cooling fans No.1 and No.2 operate at low speed.

•  If the operation could not be confirmed, inspect for the following based on cooling fans status:

Cooling fan status

Inspection item

Cooling fan No.1

Cooling fan No.2
Stop
Low
•  Cooling fan relay No.1 (Stuck open)
•  Wiring harness in battery—cooling fan relay No.1—cooling fan No.1 (Open circuit, Fuse is melt by short to ground)
•  Wiring harness in cooling fan No.1—body ground (Open circuit)
•  Cooling fan No.1 (Internal circuit open)
Low
Stop
•  Cooling fan relay No.4 (Stuck open)
•  Wiring harness in battery—cooling fan relay No.4—cooling fan No.2 (Open circuit, Fuse is melt by short to ground)
•  Wiring harness in cooling fan No.2—body ground (Open circuit)
•  Cooling fan No.2 (Internal circuit open)
Middle
Middle
•  Cooling fan relay No.2 (Stuck close)
•  Wiring harness in cooling fan relay No.2—cooling fan No.1 (Short to ground)
•  Wiring harness in cooling fan relay No.2—cooling fan No.2 (Short to ground)
•  Cooling fan relay No.3 (Stuck close)
•  Wiring harness in cooling fan relay No.3—cooling fan No.1 (Short to power supply circuit)
•  Wiring harness in cooling fan relay No.3—cooling fan No.2 (Short to power supply circuit)

6.  Using the M-MDS simulation function, turn FAN1 and FAN2 from the off position to the ON position, and verify that cooling fan No.1 operates at high speed and cooling fan No.2 operates at middle speed.

•  If the operation could not be confirmed, inspect for the following based on cooling fans status:

Cooling fan status

Inspection item

Cooling fan No.1

Cooling fan No.2
High
Stop
•  Wiring harness in cooling fan relay No.3—cooling fan No.2 (Open circuit)
•  Cooling fan No.2 (Internal circuit open)
Low
Stop
•  Cooling fan relay No.3 (Stuck open)
•  Wiring harness in battery—cooling fan relay No.3—branch point between cooling fans No.1 and No.2 (Open circuit, Fuse is melt by short to ground)
•  Wiring harness in cooling fan relay No.3—cooling fan No.1 (Fuse is melt by short to ground)
•  Wiring harness in cooling fan relay No.3—cooling fan No.2 (Fuse is melt by short to ground)
Middle
Low
•  Cooling fan relay No.2 (Stuck open)
•  Wiring harness in cooling fan No.2—body ground (Open circuit)
High
Low
•  Wiring harness in cooling fan No.2—cooling fan relay No.2 (Open circuit)
•  Cooling fan No.2 (Internal circuit open)
Middle
Middle
•  Wiring harness in cooling fan No.1—cooling fan relay No.2 (Open circuit)
•  Cooling fan No.1 (Internal circuit open)

7.  Using the M-MDS simulation function, turn FAN1, FAN2, and FAN3 from the off position to the ON position, and verify that cooling fans No.1 and No.2 operate at high speed.

•  If the operation could not be confirmed, inspect for the following based on cooling fans status:

Cooling fan status

Inspection item

Cooling fan No.1

Cooling fan No.2
High
Middle/Low
•  Cooling fan No.2 (Internal circuit open)


Variable Valve Timing Control System Operation Inspection


When idling cannot be continued

1.  Remove the OCV and verify that the spool valve is at maximum retard position. (See OIL CONTROL VALVE (OCV) REMOVAL/INSTALLATION [MZR 2.0, MZR 2.5].)

2.  Connect the OCV.

3.  Switch the ignition to ON.

4.  Verify that the spool valve is at maximum retard position.

•  If the spool valve is stuck in the advance direction, inspect for the following:
―  Short circuit in wiring harnesses or connectors between OCV and PCM

5.  Inspect the variable valve timing actuator. (See VARIABLE VALVE TIMING ACTUATOR INSPECTION [MZR 2.0, MZR 2.5].)


When idling can be continued

1.  Disconnect the OCV connector.

2.  Warm up the engine and idle it.

3.  Apply battery voltage to the OCV and verify that the engine idles roughly or stalls.

•  If the engine idles roughly or stalls, inspect the timing chain component (valve timing deviation).
•  If the engine does not idle roughly or stalls, go to the next step.

4.  Remove the OCV and perform spool valve operation inspection. (See OIL CONTROL VALVE (OCV) REMOVAL/INSTALLATION [MZR 2.0, MZR 2.5].)

•  If not as specified, inspect the following:
―  OCV (See OIL CONTROL VALVE (OCV) INSPECTION [MZR 2.0, MZR 2.5].)
―  Harnesses and connectors between OCV and PCM open or short
•  If as specified, inspect the following hydraulic passages for clogging or leakage or both:
―  Oil pressure switch—OCV
―  OCV—Camshaft
―  Camshaft internal passage

5.  If they are normal, replace the camshaft pulley (with built-in variable valve timing actuator). (See VARIABLE VALVE TIMING ACTUATOR INSPECTION [MZR 2.0, MZR 2.5].)