ENGINE CONTROL SYSTEM OPERATION INSPECTION [YF (2.0L Zetec)]

Main Relay Operation Inspection

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

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

- Main relay (See RELAY INSPECTION.)

- Wiring harness and connector between ignition switch and main relay terminal 85

- Wiring harness and connector between GND and main relay terminal 86

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.

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

- Accelerator cable free play

- Fuel injector insulator

- Engine compression

Idle Air Control System Inspection

Engine coolant temperature compensation inspection

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

2. Access 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.

- Cylinder head temperature sensor and related wiring harness

- IAC valve and related wiring harness (See IDLE AIR CONTROL (IAC) VALVE INSPECTION [YF (2.0L Zetec)].)

Load compensation inspection

1. Start the engine and idle it.

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

3. Verify that DTCs P0506, P0507, or P0511 are not displayed.

• If DTCs P0506, P0507, or P0511 are displayed, perform the DTC inspection. (See DTC TABLE [YF (2.0L Zetec)].)

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 in wiring harness between IAC valve terminal 2 and PCM terminals 83

- Open or short circuit in wiring harness between main relay terminal 87 and PCM terminal 1

6. Access the following PIDs.

• ACCS

• IAC

• PSP

• RPM

Note

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

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

• If not as specified under each load condition, inspect the following.

- A/C switch and related wiring harness.

- Fan switch and related wiring harness.

- PSP switch and related wiring harness.

Fuel Injector Operation Inspection

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. Access the RPM and FUELPW1 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 below 1,300 rpm.

• If not as specified, inspect the following.

- Cylinder head temperature sensor and related wiring harness (See CYLINDER HEAD TEMPERATURE SENSOR INSPECTION [YF (2.0L Zetec)].)

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 sounds is heard, proceed to next step.

5. Measure the voltage at wiring harness-side fuel pump terminal 1.

Specification

B+ (Ignition switch is ON position)

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

- Fuel pump continuity

- Fuel pump GND

• If not as specified, inspect the following:

- Fuel pump relay (See RELAY INSPECTION.)

- Wiring harness and connector (Main relay-fuel pump relay-IFS switch-fuel pump)

- Wiring harness between fuel pump relay and PCM terminal 54

- Inertia fuel shutoff (IFS) switch

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. Access 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. Remove 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.

EGR System Operation Inspection

1. Connect the WDS or equivalent to DLC.

2. Perform KOEO self test.

3. Verify that DTCs P0401, P0402, P1400, P1401, P1405, P1406, P1408, and P1409 are not displayed.

• If DTCs P0401, P0402, P1400, P1401, P1405, P1406, P1408, or P1409 is displayed, perform the applicable troubleshooting procedure. (See DTC TABLE [YF (2.0L Zetec)].)

4. Access the DPFEGR and EGRVR PIDs.

5. Start the engine and warm it up.

6. Verify that the DPFEGR PID is below 1.1 V at idle.

7. If the DPFEGR PID is 1.1 V or more, inspect if the EGR solenoid valve is stuck open.

Note

• If the engine tends to stall increase, the engine speed with the throttle to maintain at a minimum of 1,000 rpm.

8. Verify that the DPFEGR PID value increases, when the EGR solenoid valve operates at 50% using the EGRVM PID simulation function.

• If the DPFEGR PID does not increase, inspect for the following:

- EGR solenoid valve (stuck close)

- Vacuum hose connection (improper connection or loose at intake manifold - EGR solenoid valve)

- Upstream or downstream pressure hose connection

• If the all items above are normal, perform Step 9.

9. Stop the engine.

10. Disconnect the vacuum hose at the EGR valve and plug the hose.

11. Connect a hand vacuum hose to the EGR valve.

12. Start the engine and idle it.

13. Slowly apply 27-34 kPa {8 -10 inHg} vacuum to the DPFEGR sensor and hold for 10 seconds. If the engine tends to stall, increase the engine speed with the throttle to maintain at a minimum of 1,000 rpm.

14. Verify that the DPFEGR PID voltage indicates the following:

• The EGR valve starts opening at about 5.4 kPa {1.6 inHg} vacuum indicated by increasing DPFEGR voltage.

• The DPFEGR PID voltage increases until the EGR valve is fully open. The DPFEGR PID must read 2.5 V minimum with full vacuum applied.

• The DPFEGR PID voltage is steady when the vacuum is held. If the voltage drops within a few seconds, the EGR valve or vacuum source may be leaking.

15. If the DPFEGR PID is not as specified in Step 14, inspect the following:

• EGR valve (signs of contamination, unusual wear, carbon deposits, binding and other damage)

• EGR valve port in intake manifold (restriction)

• Orifice tube (restriction)

Purge Control System Inspection

1. Start the engine.

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

3. Place your finger on the purge 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 valve-PCM terminal 56)

- Purge valve

4. Start the engine and warm it up completely.

5. Stop the engine.

6. Connect the WDS or equivalent to the DLC-2 and verify that DTC P0443 is displayed. Perform the DTC inspection. (See DTC TABLE [YF (2.0L Zetec)].)

7. Turn the ignition switch to the ON position.

8. Access ECT PID.

9. Verify that the engine coolant temperature is above 78 ×C {173 ×F}.

• If WDS or equivalent indicates below 78 ×C {173 ×F}, perform the ECT sensor inspection.

10. Access the EVAPPDC PID.

11. Verify that the operation sound is heard from purge solenoid valve while the EVAPPDC PID is 30% or over.

• If the operation sound is heard, inspect for 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.

(See PURGE SOLENOID VALVE INSPECTION [YF (2.0L Zetec)].)

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) Access 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 circuit or short to GND in wiring harness and connectors (Ignition switch-A/C relay-PCM terminal 69)

- A/C related parts

Cooling Fan Control System Operation Inspection

1. Connect the WDS or equivalent to the DLC.

2. Perform the KOEO/KOER self-test.

3. Verify that the DTC P1474 and P1479 are not displayed after KOEO/KOER self-test.

• If DTC P1474 or P1479 is displayed, perform the applicable troubleshooting procedure. (See DTC TABLE [YF (2.0L Zetec)].)

4. Turn the ignition switch to ON.

5. Verify that the A/C switch is OFF.

6. Access the LFC, MFC, and HFC PIDs.

Caution

• Operate the cooling fans using the WDS or equivalent simulation function for the shortest possible time. If they operate over an extended time period, the battery will be drained.

Note

• While the engine is running, cooling fans can not be operated by the LFC and HFC PIDs' simulation function.

7. Verify that the cooling fans operate as follows using the LFC and HFC PIDs' simulation function.

• If the cooling fans do not operate when the LFC PID is commanded ON, inspect the following.

- Low speed fan control relay (stuck open)

- High speed fan control relay (stuck close)

- Middle speed fan control relay (stuck close)

- Cooling fan motor No.2

- Cooling fan motor No.1

- Open or short circuit in wiring harnesses or connectors (Battery - Low speed fan control relay)

- Open or short circuit in wiring harnesses or connectors (Battery - Low speed fan control relay - Cooling fan motor No.1 - GND)

- Short to PWR circuit in wiring to cooling fans terminal 1 and/or 2.

• If the cooling fans do not operate when MFC PID is commanded ON, perform Step 8.

• If the cooling fans do not operate when HFC PID is commanded ON, perform Step 9.

8. Verify that the operation sound is heard from the middle speed fan control relay, when the simulation function MFC PID is changed from OFF to ON.

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

- Cooling fan motor No.2

- Open or short circuit in wiring harness or connectors (Battery - Middle speed fan relay - Cooling fan motor 2)

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

- Middle speed fan control relay (stuck open)

9. Verify that the operation sound is heard from the high speed fan control relay, when the simulation function HFC PID is changed from OFF to ON.

• If the operation sounds is heard from high speed fan control relay, inspect for following:

- Cooling fan motor No.1

- Cooling fan motor No.2

- Open or short circuit in wiring harness or connectors (Battery - High speed fan relay - Cooling fan motor No.1 or No.2

• If the operation sound is not heard from the high speed fan control relay, inspect the following:

- Middle speed fan control relay (stuck open)