NO.12 LACK/LOSS OF POWER-ACCELERATION/CRUISE[AJ (3.0L Duratec)]

• The following troubleshooting flow chart contains the fuel system diagnosis and repair procedures. Read the following warnings before performing the fuel system services:

― Fuel vapor is hazardous. It can easily ignite, causing serious injury and damage. Always keep sparks and flames away from fuel.

― Fuel line spills and leakage are dangerous. Fuel can ignite and cause serious injuries or death and damage. Fuel can also irritate skin and eyes. To prevent this, always complete “BEFORE SERVICE PRECAUTION” and “AFTER SERVICE PRECAUTION” described in this manual.

(See BEFORE SERVICE PRECAUTION[AJ (3.0L Duratec)].)

(See AFTER SERVICE PRECAUTION[AJ (3.0L Duratec)].)

STEP	INSPECTION	RESULTS	ACTION
1	• Verify the following: ― Vacuum connection ― Air cleaner element ― No air leakage from intake-air system ― No restriction of intake-air system ― Proper sealing of intake manifold and components attached to intake manifold: EGR valve, IAC solenoid valve ― Fuel quality: proper octane, contamination, winter/summer blend • Are all items normal?	Yes	Go to the next step.
No	Service if necessary. Repeat Step 1.
2	• Connect the M-MDS to the DLC–2. • Turn the ignition switch to the ON position (Engine off). • Retrieve any DTCs. • Is “PASSED” displayed?	Yes	No DTC is displayed: • Go to the next step.
No	DTC is displayed: • Go to the appropriate DTC test.
3	Is the engine overheating?	Yes	Go to symptom troubleshooting “No.17 Cooling system concerns—Overheating”.
No	Go to the next step.
4	• Connect the M-MDS to the DLC–2. • Access the RPM, MAF, TP and VSS PIDs. • Drive vehicle with monitoring PIDs. • Are PIDs within specification?	Yes	Go to the next step.
No	RPM PID: • Inspect the CKP sensor and related wiring harness for vibration and/or intermittent open/short circuit. MAF PID: • Inspect for intermittent open circuit of MAF sensor and related wire harness. TP PID: • Inspect if the TP sensor output increases smoothly. VSS PID: • Inspect for intermittent open circuit of VSS and related wire harness.
5	• Visually inspect CKP sensor and teeth of crankshaft pulley. • Are CKP sensor and teeth of crankshaft pulley normal?	Yes	Go to the next step.
No	Replace the malfunctioning part.
6	• Inspect the spark plug conditions. • Is the spark plug wet, covered with carbon or grayish white?	Yes	Spark plug is wet or covered with carbon: • Inspect for fuel leakage from fuel injector. Spark plug is grayish white: • Inspect for clogged fuel injector.
No	Install spark plugs on original cylinders. Go to the next step.
7	• Remove and shake PCV valve. • Does PCV valve rattle?	Yes	Go to the next step.
No	Replace the PCV valve.
8	• Visually inspect the exhaust system part. • Is there any deformed exhaust system part?	Yes	Replace the suspected part.
No	Go to the next step.
9	• Install the fuel pressure gauge to fuel line. • Connect the M-MDS to DLC-2. • Turn the fuel pump on using FP PID in output state control of datalogger function. • Is the fuel line pressure correct? (See FUEL LINE PRESSURE INSPECTION[AJ (3.0L Duratec)].)	Yes	Go to the next step.
No	Zero or low: Inspect the clogged fuel line. • If normal, replace the fuel pump unit. (See FUEL PUMP UNIT REMOVAL/INSTALLATION[AJ (3.0L Duratec)].) High: Replace the fuel pump unit. (See FUEL PUMP UNIT REMOVAL/INSTALLATION[AJ (3.0L Duratec)].)
10	Note • Following test is for engine stall with A/C on concern. If other symptom exists, go to the next step. • Connect the pressure gauge to the A/C low and high side pressure lines. • Turn the A/C on and measure low side and high side pressures. • Are pressure within specification?	Yes	Go to the next step.
No	If the A/C is always on, go to symptom troubleshooting “No.24 A/C always on or A/C compressor runs continuously”. For other symptoms, Inspect the following: • Refrigerant charging amount • Condenser fan operation
11	• Inspect the A/C cut-off operation. • Does the A/C cut-off work properly?	Yes	Go to the next step.
No	Inspect the A/C cut-off system components.
12	• Disconnect the vacuum hose between purge solenoid valve and intake manifold from purge solenoid valve side. • Plug opening end of vacuum hose. • Drive vehicle. • Does the engine condition improve?	Yes	Inspect if the purge solenoid valve is stuck open mechanically. Inspect the EVAP control system.
No	Go to the next step.
13	• Visually inspect CMP sensor and projections of camshaft pulley. • Are CMP sensor and projections of camshaft pulley normal?	Yes	Go to the next step.
No	Replace the malfunctioning part.
14	• Inspect the EGR system. • Is the EGR system normal?	Yes	Go to the next step.
No	Replace the malfunctioning part.
15	• Is the engine compression correct?	Yes	Inspect the following: • Valve timing • Internal transaxle components • Brake system for dragging
No	Inspect for cause.
16	• Verify the test results. ― If normal, return to the diagnostic index to service any additional symptoms. ― If malfunction remains, inspect related Service Information and perform repair or diagnosis. • If vehicle is repaired, troubleshooting completed. • If vehicle is not repaired or additional diagnostic information is not available, replace or reprogram PCM.

STEP

INSPECTION

RESULTS

ACTION

• Verify the following:

― Vacuum connection

― Air cleaner element

― No air leakage from intake-air system

― No restriction of intake-air system

― Proper sealing of intake manifold and components attached to intake manifold: EGR valve, IAC solenoid valve

― Fuel quality: proper octane, contamination, winter/summer blend

• Are all items normal?

Yes

Go to the next step.

Service if necessary.

Repeat Step 1.

• Connect the M-MDS to the DLC–2.

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

• Retrieve any DTCs.

• Is “PASSED” displayed?

Yes

No DTC is displayed:

• Go to the next step.

DTC is displayed:

• Go to the appropriate DTC test.

Is the engine overheating?

Yes

Go to symptom troubleshooting “No.17 Cooling system concerns—Overheating”.

Go to the next step.

• Connect the M-MDS to the DLC–2.

• Access the RPM, MAF, TP and VSS PIDs.

• Drive vehicle with monitoring PIDs.

• Are PIDs within specification?

Yes

Go to the next step.

RPM PID:

• Inspect the CKP sensor and related wiring harness for vibration and/or intermittent open/short circuit.

MAF PID:

• Inspect for intermittent open circuit of MAF sensor and related wire harness.

TP PID:

• Inspect if the TP sensor output increases smoothly.

VSS PID:

• Inspect for intermittent open circuit of VSS and related wire harness.

• Visually inspect CKP sensor and teeth of crankshaft pulley.

• Are CKP sensor and teeth of crankshaft pulley normal?

Yes

Go to the next step.

Replace the malfunctioning part.

• Inspect the spark plug conditions.

• Is the spark plug wet, covered with carbon or grayish white?

Yes

Spark plug is wet or covered with carbon:

• Inspect for fuel leakage from fuel injector.

Spark plug is grayish white:

• Inspect for clogged fuel injector.

Install spark plugs on original cylinders.

Go to the next step.

• Remove and shake PCV valve.

• Does PCV valve rattle?

Yes

Go to the next step.

Replace the PCV valve.

• Visually inspect the exhaust system part.

• Is there any deformed exhaust system part?

Yes

Replace the suspected part.

Go to the next step.

• Install the fuel pressure gauge to fuel line.

• Connect the M-MDS to DLC-2.

• Turn the fuel pump on using FP PID in output state control of datalogger function.

• Is the fuel line pressure correct?

(See FUEL LINE PRESSURE INSPECTION[AJ (3.0L Duratec)].)

Yes

Go to the next step.

Zero or low:

Inspect the clogged fuel line.

• If normal, replace the fuel pump unit.

(See FUEL PUMP UNIT REMOVAL/INSTALLATION[AJ (3.0L Duratec)].)

High:

Replace the fuel pump unit.

(See FUEL PUMP UNIT REMOVAL/INSTALLATION[AJ (3.0L Duratec)].)

Note

• Following test is for engine stall with A/C on concern. If other symptom exists, go to the next step.

• Connect the pressure gauge to the A/C low and high side pressure lines.

• Turn the A/C on and measure low side and high side pressures.

• Are pressure within specification?

Yes

Go to the next step.

If the A/C is always on, go to symptom troubleshooting “No.24 A/C always on or A/C compressor runs continuously”.

For other symptoms, Inspect the following:

• Refrigerant charging amount

• Condenser fan operation

• Inspect the A/C cut-off operation.

• Does the A/C cut-off work properly?

Yes

Go to the next step.

Inspect the A/C cut-off system components.

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

• Plug opening end of vacuum hose.

• Drive vehicle.

• Does the engine condition improve?

Yes

Inspect if the purge solenoid valve is stuck open mechanically.

Inspect the EVAP control system.

Go to the next step.

• Visually inspect CMP sensor and projections of camshaft pulley.

• Are CMP sensor and projections of camshaft pulley normal?

Yes

Go to the next step.

Replace the malfunctioning part.

• Inspect the EGR system.

• Is the EGR system normal?

Yes

Go to the next step.

Replace the malfunctioning part.

• Is the engine compression correct?

Yes

Inspect the following:

• Valve timing

• Internal transaxle components

• Brake system for dragging

Inspect for cause.

• Verify the test results.

― If normal, return to the diagnostic index to service any additional symptoms.

― If malfunction remains, inspect related Service Information and perform repair or diagnosis.

• If vehicle is repaired, troubleshooting completed.

• If vehicle is not repaired or additional diagnostic information is not available, replace or reprogram PCM.

12	Lack/loss of power—acceleration/cruise
DESCRIPTION	• Performance is poor under load (e.g. powers down when climbing hills).
POSSIBLE CAUSE	• Improper A/C system operation • Erratic signal or no signal from CMP sensor • Air leakage from intake-air system parts • Purge control solenoid malfunction • EGR valve malfunction • Brake dragging • Erratic signal from CKP sensor • Low engine compression • Vacuum leakage • Poor fuel quality • Spark leakage from ignition coils • Air cleaner restriction • PCV valve malfunction • Improper valve timing due to jumping out of timing belt • Restriction in exhaust system • Intermittent open or short in fuel pump circuit • Inadequate fuel pressure • Fuel pump mechanical malfunction • Fuel leakage from fuel injector • Fuel injector clogging • Intermittent open or short of MAF sensor, TP sensor and VSS • ATX malfunction Warning • The following troubleshooting flow chart contains the fuel system diagnosis and repair procedures. Read the following warnings before performing the fuel system services: ― Fuel vapor is hazardous. It can easily ignite, causing serious injury and damage. Always keep sparks and flames away from fuel. ― Fuel line spills and leakage are dangerous. Fuel can ignite and cause serious injuries or death and damage. Fuel can also irritate skin and eyes. To prevent this, always complete “BEFORE SERVICE PRECAUTION” and “AFTER SERVICE PRECAUTION” described in this manual. (See BEFORE SERVICE PRECAUTION[AJ (3.0L Duratec)].) (See AFTER SERVICE PRECAUTION[AJ (3.0L Duratec)].)