NO.13 KNOCKING/PINGING-ACCELERATION/CRUISE [L8, LF]

id0103a0812100

13 | KNOCKING/PINGING—ACCELERATION/CRUISE
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DESCRIPTION | • Sound is produced when air/fuel mixture is ignited by something other than spark plug (such as hot spot in combustion chamber).
POSSIBLE CAUSE | • Engine overheating due to cooling system malfunction • IAT sensor malfunction • MAF sensor malfunction • Erratic signal from CMP sensor • KS malfunction • Inadequate engine compression • Inadequate fuel pressure • PCM 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 [L8, LF].) (See AFTER SERVICE PRECAUTION [L8, LF].) 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
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1 | Connect the M-MDS to the DLC-2. Perform the PID/DATA Monitor and Record Procedure and access the ECT PID. (See ON-BOARD DIAGNOSTIC TEST [L8, LF].) Verify the ECT PID is less than 116 °C {241 °F} during driving. Is the ECT PID less than the specification? | Yes | Go to the next step.
No | Go to the symptom troubleshooting “NO.17 COOLING SYSTEM CONCERNS-OVERHEATING”. (See NO.17 COOLING SYSTEM CONCERNS-OVERHEATING [L8, LF].)
2 | Connect the M-MDS to the DLC-2. Perform the PID/DATA Monitor and Record Procedure and access the following PIDs: (See ON-BOARD DIAGNOSTIC TEST [L8, LF].) • IAT • MAF • SPARKADV Are the PIDs normal? (See PCM INSPECTION [L8, LF].) | Yes | Go to the next step.
No | IAT: • Inspect the IAT sensor. (See INTAKE AIR TEMPERATURE (IAT) SENSOR INSPECTION [L8, LF].) MAF: • Inspect the MAF sensor. (See MASS AIR FLOW (MAF) SENSOR INSPECTION [L8, LF].) SPARKADV: • Inspect the CMP sensor and KS. (See CAMSHAFT POSITION (CMP) SENSOR INSPECTION [L8, LF].) (See KNOCK SENSOR (KS) INSPECTION [L8, LF].) Repair or replace the malfunctioning part according to the inspection results.
3 | Connect the M-MDS to the DLC-2. Perform the KOEO/KOER self test and the DTC Reading Procedure. (See KOEO/KOER SELF TEST [L8, LF].) (See ON-BOARD DIAGNOSTIC TEST [L8, LF].) Are any DTCs present? | Yes | Go to the appropriate DTC inspection. (See DTC TABLE [L8, LF].)
No | Go to the next step.
4 | Perform the “COMPRESSION INSPECTION”. (See COMPRESSION INSPECTION [L8, LF].) Is the engine compression correct? | Yes | Go to the next step.
No | Inspect for cause.
5 | Install fuel pressure gauge between the fuel pipe and fuel distributor. Start the engine and idle it. Measure the fuel line pressure during idle. (See FUEL LINE PRESSURE INSPECTION [L8, LF].) Is fuel line pressure correct during idle? | Yes | Inspect the ignition timing. Repair or replace the malfunctioning part according to the inspection results.
No | Zero or low: • Inspect the fuel pump and fuel pump relay related circuit. • Inspect for clogged fuel line. • If there is no malfunction: ― Replace the fuel pump unit. (See FUEL PUMP UNIT REMOVAL/INSTALLATION [L8, LF].) • If there is a malfunction: ― Repair or replace the malfunctioning part according to the inspection results. High: • Replace the fuel pump unit. (See FUEL PUMP UNIT REMOVAL/INSTALLATION [L8, LF].)
6 | Verify test results. • If normal, return to diagnostic index to service any additional symptoms. (See ENGINE SYMPTOM TROUBLESHOOTING [L8, LF].) • If malfunction remains, inspect related Service information perform repair or diagnosis. ― If vehicle repaired, troubleshooting completed. ― If vehicle not repaired or additional diagnostic information not available, replace the PCM. (See PCM REMOVAL/INSTALLATION [L8, LF].)