NO.13 KNOCKING/PINGING-ACCELERATION/CRUISE [YF (2.0L Zetec)]

id0103c7812100

13

KNOCKING/PINGING - ACCELERATION/CRUISE

DESCRIPTION

Sound is heard 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
• MAF sensor malfunction
• Knock sensor malfunction
• Erratic signal from CMP sensor
• Inadequate engine compression
• Inadequate fuel pressure
Warning
The following troubleshooting flow chart contains fuel system diagnosis and repair procedures. Read the following warnings before performing any fuel system-related procedures:
• 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 [YF (2.0L Zetec)].)
(See AFTER SERVICE PRECAUTION [YF (2.0L Zetec)].)
Caution
• Disconnecting/connecting quick release connectors without cleaning them may possibly cause damage to the fuel pipe or quick release connector. Always clean the quick release connector joint area before disconnecting/connecting, and make sure that it is free of foreign material.

Diagnostic procedure

STEP

INSPECTION

RESULTS

ACTION

1
Connect the WDS or equivalent to the DLC-2.
Access the ECT PID.
Verify that the ECT PID is less than 116×C {241×F} while driving.
Is the ECT PID less than specification?
Yes
Go to the next step.
No
Inspect the cooling system for cause of overheating.
2
Connect the WDS or equivalent to the DLC-2.
Access the IAT, MAF, and SPARKADV PIDs.
Monitor each PID.
Are the PIDs normal?
Yes
Go to the next step.
No

IAT PID: Inspect IAT sensor.

MAF PID: Inspect MAF sensor.

SPARKADV PID: Inspect CMP sensor and knock sensor.

3
Connect the WDS or equivalent to the DLC-2.
Retrieve any continuous memory, KOEO and KOER DTCs using the WDS or equivalent.
Are any DTCs displayed?
Yes

DTC is displayed:

Go to the appropriate DTC inspection.
No

No DTC is displayed:

Go to the next step.
4
Is engine compression correct?
Yes
Go to the next step.
No
Inspect for cause.
5
Install a fuel pressure gauge to the fuel line.
Start the engine and idle it.
Measure the fuel line pressure during idle.
Is the fuel line pressure correct during idle?
Yes
Go to the next step.
No

Low:

Inspect the fuel line for clogging.
• If there is no malfunction, replace the fuel pump unit.

High:

Replace the fuel pump unit.
6
Inspect the knock sensor.
Is the knock sensor normal?
Yes
Inspect the ignition timing.
No
Replace the knock sensor.
7
Verify test results.
• If normal, return to the diagnostic index to service any additional symptoms.
• If any malfunction remains, inspect related service information and, repair or diagnosis accordingly.
- If the vehicle is repaired, troubleshooting completed.
- If the vehicle is not repaired or additional diagnostic information is not available, replace the PCM.
(See PCM REMOVAL/INSTALLATION [YF (2.0L Zetec)].)