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


13	KNOCKING/PINGING - ACCELERATION/CRUISE
DESCRIPTION	Sound is produced when the air/fuel mixture is ignited by something other than the spark plug (e.g., hot spot in combustion chamber).
POSSIBLE CAUSE	• Engine overheating due to a 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 REPAIR PROCEDURE" and "AFTER REPAIR PROCEDURE" described in this manual. (See BEFORE REPAIR PROCEDURE [LF, L3].) (See AFTER REPAIR PROCEDURE [LF, L3].) Caution • Disconnecting/connecting the quick release connector without cleaning it may possibly cause damage to the fuel pipe and the quick release connector. Always clean the quick release connector joint area before disconnecting/connecting, and make sure that it is free of foreign material.


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 ECT PID less than the specification?	Yes	Go to the next step.
1		No	Inspect the cooling system for the cause of overheating.
2	Connect the WDS or equivalent to the DLC-2. Access the IAT., MAF and SPARKADV PIDs. Monitor each PID. (See PCM INSPECTION [LF, L3].) Are the PIDs normal?	Yes	Go to the next step.
2		No	IAT PID: Inspect the IAT. sensor MAF PID: Inspect the MAF sensor SPARKADV PID: Inspect the CMP sensor and knock sensor.
3	Connect the WDS or equivalent to the DLC-2. Retrieve any continuous memory, KOEO and KOER DTCs. Are any DTCs displayed?	Yes	DTC is displayed: Go to the appropriate DTC test.
3		No	No DTC is displayed: Go to the next step.
4	Is the engine compression correct?	Yes	Go to the next step.
4	Is the engine compression correct?	No	Inspect for the cause.
5	Install a fuel pressure gauge between fuel pipe and fuel distributor. Start the engine and run it at idle. Measure the fuel line pressure at idle. Is the fuel line pressure correct at idle? (See FUEL LINE PRESSURE INSPECTION [LF, L3])	Yes	Inspect the ignition timing.
5		No	Zero or low: Inspect for a clogged fuel line. If normal, replace the fuel pump unit. High: Replace the fuel pump unit.
6	Verify the test results. • If normal, return to the diagnostic index to service any additional symptoms. • If the malfunction remains, replace the PCM.