#
ENGINE CONTROL SYSTEM OPERATION INSPECTION [WITHOUT WU-TWC]

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## Main Relay Operation Inspection

1. Verify that the main relay clicks when the ignition switch turned to the ON position and off.

  • If there is no operation sound, inspect the following.

  - Main relay (See RELAY INSPECTION.)
  - Immobilizer system (PATS) operation (if equipped)
  - Wiring harness and connector between ignition switch and main relay terminal A.
  - Wiring harness and connector between PCM terminal 1AW and main relay terminal E.

## Intake Manifold Vacuum Inspection

1. Verify that the air intake hoses are installed properly.

2. Start the engine and idle it.

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.

Specification

  More than 60 kPa {450 mmHg, 18 inHg}

  Note

  • Air suction can be located by spraying lubricant on the area where the suction is occurring and revving the engine.

  - Air suction at throttle body, intake manifold and PCV valve installation points
  - Accelerator cable free play
  - Fuel injector insulator
  - Engine compression
  (See COMPRESSION INSPECTION [ZJ, ZY].)

## Idle Air Control System Inspection

### Engine coolant temperature compensation inspection

1. Connect the WDS or equivalent to the DLC-2.

2. Select the following PIDs.

  • 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.)
  - IAC valve and related wiring harness
  (See IDLE AIR CONTROL (IAC) VALVE INSPECTION.)

### Load compensation inspection

1. Start the engine and run at idle.

2. Connect the WDS or equivalent to the DLC-2.

3. Verify that P0511 not displayed.

  • If P0511 is displayed, carry out the DTC inspection.
  (See DTC TABLE.)

4. Change the duty value of the IAC valve to 100% using the IAC PID.

5. Verify that the idle speed increases.

  • If the idle speed does not change, inspect the following.

  - IAC valve air passage
  - Open or short circuit between the IAC valve connector terminals and PCM connector terminals 2X and 2AB

6. Select the following PIDs.

  • ACSW
  • IAC
  • PSP
  • RPM

  Note

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

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

  • If it is not as specified load condition, inspect the following.

  - Refrigerant pressure switch (low, high) and related wiring harness
  (See REFRIGERANT PRESSURE SWITCH INSPECTION.)
  - Fan switch and related wiring harness
  (See FAN SWITCH INSPECTION.)
  - PSP switch and the related wiring harness
  (See POWER STEERING PRESSURE (PSP) SWITCH INSPECTION.)

Engine speed

Load condition | Engine speed (rpm)*1
--- | ---
MTX | ATX
No load | 650-750
E/L operating | E/L 40A or less | 650-750
E/L more than 40A | 700-800
P/S operating | 700-800
A/C operating*2 | Refrigerant pressure low*3 | 650-750
Refrigerant pressure high*4 | 700-800

  *1 :
Neutral or P position
  *2 :
A/C switch and fan switch are on.
  *3 :
Refrigerant pressure switch (middle pressure) is off.
  *4 :
Refrigerant pressure switch (middle pressure) is on.

## Variable Intake-air System (VIS) Operation Inspection

1. Connect the WDS or equivalent to the DLC-2.

2. Carry out the KOEO self-test.

3. Verify that DTC P0660 is not displayed.

  • If DTC P0660 is displayed, carry out the DTC inspection.

4. Turn the ignition switch to the ON position (Engine off).

5. Turn the VIS shutter valve actuator from ON to OFF and from OFF to ON using the IMTV PID and verify that the operation sound of the actuator is heard.

  • If the operation sound is not heard, inspect the following.

  - VIS shutter valve actuator
  (See VARIABLE INTAKE-AIR SYSTEM (VIS) SHUTTER VALVE ACTUATOR INSPECTION [ZY].)
  - VIS shutter valve actuator stuck open or close

## Variable Tumble Control System (VTCS) Operation Inspection

1. Connect the WDS or equivalent to the DLC-2.

2. Carry out the KOEO self-test.

3. Verify that DTC P2008 is not displayed.

  • If DTC P2008 is displayed, carry out the DTC inspection.

4. Turn the ignition switch to the ON position (Engine off).

5. Monitor the ECT, RPM and IMRC PIDs.

6. Verify that the ECT PID is 60°C {140°F} or less.

7. Start the engine.

8. Verify that the IMRC PID is as show below when the ECT PID is 60°C {140°F} or less.

  • If the IMRC PID is not as specified, inspect as follows.

  - TP sensor (misadjustment)

Engine speed

Engine speed | 3,250 rpm
--- | ---
Or less | Or more
IMRC PID | OFF | ON

9. Turn the VTCS shutter valve actuator from ON to OFF and from OFF to ON using the IMRC PID and verify that the operation sound of the actuator is heard.

  • If the operation sound is not heard, inspect the following.

  - VTCS shutter valve actuator
  (See VARIABLE TUMBLE CONTROL SYSTEM (VTCS) SHUTTER VALVE ACTUATOR INSPECTION.)
  - VTCS shutter valve actuator is stuck open or close

## Fuel Injector Operation Inspection

STEP | INSPECTION | RESULTS | ACTION
--- | --- | --- | ---
1 | While cranking the engine, inspect for fuel injector the operation sound at each cylinder using a soundscope. Is the operation sound heard? | Yes | Fuel injector operation is normal.
No | All cylinders not heard: Go to the next step. Some cylinders not heard: Go to Step 3.
2 | Carry out main relay operation inspection. Is main relay operation normal? | Yes | Inspect the following: • Fuel injector power system related wiring harness and connectors • PCM connectors • Fuel injector ground and related wiring harness and connectors
No | Repair or replace the malfunctioning parts.
3 | Change the fuel injector connector of the fuel injector that is not operating with an fuel injector. Is the operation sound heard? | Yes | Go to the next step.
No | Replace the fuel injector.
4 | Are the wiring harness and connectors of the non-operational the fuel injector normal? (Open or short) | Yes | Inspect the PCM terminal voltage of the fuel injector signal.
No | Repair or replace the malfunctioning parts.

## Fuel Cut Control System Inspection

1. Warm up the engine and idle it.

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

3. Connect the WDS or equivalent to the DLC-2.

4. Select the RPM and FUELPW PIDs.

5. Monitor both PIDs while performing the following steps.

  (1) Depress the accelerator pedal and increase the engine speed to 4,000 rpm.
  (2) Release the accelerator pedal (brake pedal is not depressed) and verify that the fuel injector duration time is 0 ms, and 2-5 ms when the engine speed drops to 1,200 rpm or less.

  • If not as specified, inspect the following.

  - ECT sensor and related wiring harness
  (See ENGINE COOLANT TEMPERATURE (ECT) SENSOR INSPECTION.)
  - Neutral/clutch switch and related wiring harness (MTX)
  (See CLUTCH SWITCH INSPECTION.)
  - TR switch and related wiring harness (ATX)
  (See TRANSAXLE RANGE (TR) SWITCH INSPECTION [FN4A-EL].)

## Fuel Pump Operation Inspection

1. Connect the WDS or equivalent to the DLC-2.

2. Remove the fuel-filler cap.

3. Turn the ignition switch to the ON position.

4. Turn the fuel pump relay from OFF to ON using the FP PID and inspect if the operation sound is heard.

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

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

Specification

  B+ (Ignition switch is on)

  • If the voltage is as specified, inspect the following.

  - Fuel pump continuity
  - Fuel pump ground
  - Wiring harness between fuel pump relay and PCM terminal 1AH (without immobilizer system), 1AC (with immobilizer system)

  • If not as specified, inspect the following.

  - Fuel pump relay (See RELAY INSPECTION.)
  - Wiring harness and connector (Main relay-fuel pump relay-fuel pump)

## Fuel Pump Control System Inspection

1. Connect the WDS or equivalent to the DLC-2.

2. Turn the ignition switch to the ON position.

3. Select FP PID.

4. Turn the fuel pump relay from off to on and inspect if the operation sound of the fuel pump relay is heard.

  • If no operation sound is heard, inspect the fuel pump relay.
  • If the fuel pump relay is normal, inspect the following.

  - Wiring harnesses and connectors (Main relay-fuel pump relay-PCM)

## 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 spark plugs. • Remove the spark plugs. • Reconnect the spark plugs to ignition coil. • Ground the spark plugs to engine. • Is a strong blue spark visible at each cylinder while cranking? | Yes | The Ignition system is normal.
No | Some cylinders do not spark: • Go to the next step. All cylinders do not spark: • Go to Step 4.
2 | • Inspect the spark plugs for damage, wear, carbon deposits, and proper plug gap. • Are the spark plugs normal? | Yes | Go to the next step.
No | Replace the spark plugs, then go to Step.1.
3 | • Inspect the following wiring harnesses for open or short: - Ignition coil No.1 terminal C-PCM terminal 2Y - Ignition coil No.2 terminal C-PCM terminal 2U - Ignition coil No.3 terminal C-PCM terminal 2Q - Ignition coil No.4 terminal C-PCM terminal 2M • Are wiring harnesses normal? | Yes | Inspect and replace the ignition coil. (See IGNITION COIL INSPECTION [ZJ, ZY].)
No | Repair or replace the malfunctioning part, then go to Step.1.
4 | • Measure the voltage at terminal A in each ignition coils. • Is the voltage reading B+? | Yes | Go to the next step.
No | Inspect the power supply circuit of the ignition coils.
5 | • Does the PCM connector or ignition coil connectors have poor connection? | Yes | Repair or replace the connector, then go to Step.1.
No | Go to the next step.
6 | • Are the following parts normal? - CKP sensor and crankshaft pulley | Yes | Inspect for open or short in the wiring harness and connector of the CKP sensor.
No | Repair or replace the malfunctioning part, then go to Step.1.

## Purge Control System Inspection

1. Connect the WDS or equivalent to the DLC-2.

2. Start the engine and idle it.

3. Select the ECT PID.

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

  • If the WDS or equivalent indicates 60°C {140°F} or less, carry out the ECT sensor inspection.

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

6. Put a finger to the purge solenoid valve and verify that vacuum is applied when the engine is cold.

  • If there is no vacuum, inspect the following.

  - Wiring harness and connectors (Purge solenoid valve-PCM terminal 2AV)
  - Purge solenoid valve

7. Stop the engine.

8. Verify that the DTC P0443 is shown. Carry out DTC inspection. (See DTC TABLE.)

9. Turn the ignition switch to the ON position.

10. Select the EVAPCP PID.

11. Increase the duty value of the purge solenoid valve to 50% and inspect if the operation sound of the valve is heard.

  • If the operation sound is heard, inspect for a loose or damaged vacuum hose. (Intake manifold-purge solenoid valve-charcoal canister)
  • If the operation sound is not heard, carry out the purge solenoid valve inspection.

## A/C Cut-off Control System Inspection

1. Start the engine.

2. Turn the A/C switch and 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".

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.
  (1) Connect the WDS or equivalent to the DLC-2.
  (2) Turn the A/C switch off.
  (3) Turn the ignition switch to the ON position.
  (4) Select the ACCS PID.
  (5) Turn the A/C relay from off to on and inspect if the operation sound of the relay is heard.

  • If the operation sound is heard, inspect the TP PID.
  • If the operation sound is not heard, inspect the following.

  - A/C relay
  - Open or short to ground circuit in wiring harness and connectors (Ignition switch-A/C relay-PCM terminal 1AL)
  - A/C related parts

## Cooling Fan Control System Inspection

### Cooling fan system operation

Engine condition | Cooling fan relay No.1 | Cooling fan relay No.2
ECT 100°C {212°F} or less | OFF | OFF
ECT 100°C {212°F} or more (until 97°C {207°F} or less) | ON | OFF
ECT 108°C {228°F} or more (until 105°C {230°F}) | ON | ON
A/C and fan switches are on. | ON | ON
ECT sensor malfunction | ON | ON

1. Connect the WDS or equivalent to the DLC-2.

2. Verify that the ECT PID is 100°C {212°F} or less.

3. Verify that the A/C switch and fan switch are off.

4. Start the engine and idle it.

5. Verify that the cooling fan is not operating.

  • If the cooling fan is operating, inspect the following:
  (1) Verify that the ACCS PID is OFF.

  • If the ACCS PID is ON, inspect for a short to ground circuit between refrigerant pressure switch and PCM terminal 1Q.

  (2) Verify that the FAN1 PID is OFF.

  • If the FAN1 PID is ON, inspect the following:

  - DTC for ECT sensor (P0117, P0118)

  • If the FAN1 PID is ON, inspect the following:

  - Cooling fan relay No.1
  - Short to ground circuit between cooling fan relay No.1 and PCM terminal 1AT
  - Short to power between cooling fan relay No.1 and cooling fan motor
  - Cooling fan relay No.2
  - Short to ground circuit between cooling fan relay No.2 and PCM terminal 1I
  - Short to power between cooling fan relay No.2 and cooling fan motor

6. Warm up the engine to the engine coolant temperature is 100°C {212°F} or more.

7. Verify that the cooling fan is operating.

  • If the cooling fan is not operating, inspect following procedure.
  (1) Cool the engine until the engine coolant temperature is 97°C {207°F} or less.
  (2) Select the FAN1 PID.
  (3) Send ON and verify that the operation sound from cooling fan relay No.1 is heard.

  • If the operation sound is heard, inspect the following:

  - Open circuit between cooling fan relay No.1 and cooling fan motor
  - Open circuit between cooling fan motor and ground.
  - Cooling fan motor

  • If the operation sound is not heard, inspect the following:

  - Cooling fan relay
  - Open circuit between ignition switch and PCM terminal 1AT through cooling fan relay

8. Turn the A/C switch and fan switch to ON with the engine idling.

9. Verify that the cooling fan speed is higher than Step 7.

  • If the cooling fan speed does not rise, inspect following procedure.
  (1) Verify that ACCS PID is ON.

  • If the ACCS PID is OFF, inspect following:

  - A/C switch
  - Fan switch
  - Refrigerant pressure switch (low & high pressure)
  - Evaporator temperature sensor (Evaporator temperature is too low.)
  - Open circuit between refrigerant pressure switch and PCM terminal 1Q

  (2) Select the FAN2 PID.
  (3) Send ON and verify that the operation sound from cooling fan relay No.2 is heard.

  • If the operation sound is heard, inspect the following:

  - Open circuit between cooling fan relay No.2 and cooling fan motor
  - Open circuit between cooling fan motor and ground
  - Cooling fan

  • If the operation sound is not heard, inspect the following:

  - Cooling fan relay No.2
  - Open circuit between ignition switch and PCM terminal 2I through cooling fan relay No.2.

## Variable Valve Timing Control System Operation Inspection

### When idling cannot be continued

1. Remove the oil control valve (OCV) and verify that the spool valve is at maximum retard position.

2. If the spool valve is stuck in advance direction, replace the OCV.

3. Connect the OCV.

4. Turn the ignition switch to the ON position.

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

6. If the spool valve is stuck in advance direction, inspect for the following.

  • Short circuit in harnesses or connectors between the OCV and the PCM.

7. Inspect the variable valve timing actuator.

### When idling can be continued

1. Warm up the engine.

2. Connect the WDS or equivalent to the DLC-2.

3. Idle the engine.

4. Select the VT DUTY1 PID.

5. Set the OCV duty valve to 100% and verify that the engine idles roughly or stalls.

  • If as specified, inspect the timing belt component (valve timing deviation).
  • If not as specified, go to the next step.

6. Remove the OCV and connect the OCV connector to the OCV.

7. Turn the ignition switch to the ON position.

8. Select the VT DUTY1 PID.

9. Set the OCV duty value to 100% and verify that the spool valve operates in the advance direction.

10. If not as specified, inspect the following.

  • OCV operation.
  • Harnesses and connectors between the OCV and the PCM for open or short circuit.

11. Inspect the following hydraulic passages for clogging and/or leakage.

  • Oil pressure switch-OCV
  • OCV-camshaft
  • Camshaft internal passage

12. If they are normal, replace the intake camshaft pulley (with a built-in variable valve timing actuator).