NO.13 KNOCKING/PINGING-ACCELERATION/CRUISE [AJ (3.0L Duratec)]


13	Knocking/pinging-acceleration/cruise
DESCRIPTION	• Sound is produced when air/fuel mixture is ignited by something other than spark plug (e.g. hot spot in combustion chamber).
POSSIBLE CAUSE	• Engine overheating due to cooling system malfunction • ECT sensor malfunction • IAT sensor malfunction • Inadequate engine compression • Inadequate fuel pressure • Knock sensor and related circuit 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)].)


STEP	INSPECTION	RESULTS	ACTION
1	• Connect WDS or equivalent to DLC-2. • Access ECT PID. • Verify ECT PID is below 116 × C {241 × F} during driving. • Is ECT PID below specification?	Yes	Go to the next step.
1		No	Inspect cooling system for cause of overheating.
2	• Connect WDS or equivalent to DLC-2. • Turn key to ON (Engine OFF). • Retrieve any DTCs. • Is "PASSED" displayed?	Yes	No DTC is displayed: • Go to the next step.
2		No	DTC is displayed: • Go to appropriate DTC test.
3	• Is engine compression correct?	Yes	Go to the next step.
3	• Is engine compression correct?	No	Inspect for cause.
4	• Install fuel pressure gauge to the fuel line. • Start engine and run it at idle. • Measure fuel line pressure at idle. • Is fuel line pressure correct at idle? (See FUEL LINE PRESSURE INSPECTION [AJ (3.0L Duratec)])	Yes	Go to the next step.
4		No	Zero or low: Inspect the fuel pump and fuel pump relay related circuit. Inspect 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)].)
5	• Inspect knock sensor. (See KNOCK SENSOR (KS) INSPECTION [AJ (3.0L Duratec)].) • Is knock sensor okay?	Yes	Inspect ignition timing.
5		No	Replace knock sensor.
6	• Verify test results. - If okay, return to 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 PCM.