NO.13 KNOCKING/PINGING-ACCELERATION/CRUISE [L3]

BME010300103251

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
• MAF sensor malfunction
• Knock sensor malfunction
• Erratic signal from CMP sensor
• Inadequate engine compression
• Inadequate fuel pressure
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 [L3].)
(See AFTER SERVICE PRECAUTION [L3].)
Caution
• Disconnecting/connecting quick release connector without cleaning it may possibly cause damage to fuel pipe and quick release connector. Always clean 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 ECT PID.
Verify ECT PID is less than 116°C {241°F} during driving.
Is ECT PID less than the 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 IAT, MAF and SPARKADV PIDs.
Monitor each PID.
Are PIDs normal?
Yes
Go to the next step.
No

IAT PID: Inspect the IAT sensor

MAF PID: Inspect the MAF sensor

SPARKADV PID: Inspect the CMP sensor and the knock sensor.

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

DTC is displayed:

Go to the applicable DTC inspection.
No

No DTC is displayed:

Go to the next step.
4
Is the engine compression correct?
Yes
Go to the next step.
No
Inspect for cause.
5
Install a fuel pressure gauge between the fuel pipe and fuel the distributor.
Start the engine and run it at idle.
Measure the fuel line pressure at idle.
Is fuel line pressure correct at idle?
Yes
Inspect ignition timing.
No

Zero or low:

Inspect for clogged fuel line.
If normal, replace the fuel pump unit.

High:

Replace the fuel pump unit.
6
Verify test results.
• If normal, return to diagnostic index to service any additional symptoms.
• If malfunction remains, replace PCM.