NO.13 KNOCKING/PINGING-ACCELERATION/CRUISE [MZR 1.8, MZR 2.0, MZR 2.5]

id0103d4812100

13

KNOCKING/PINGING—ACCELERATION/CRUISE
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
•  ECT sensor malfunction
•  Erratic signal to PCM
―  IAT sensor malfunction
―  MAF sensor malfunction
•  PCM DTC is stored
•  Low engine compression
•  Excessive or insufficient fuel pressure
―  Fuel pump relay or fuel pump circuit malfunction
―  Clogging fuel line
―  Pressure regulator malfunction (built-in fuel pump unit)
―  Fuel pump unit malfunction
•  KS malfunction
•  Improper ignition timing
Warning
•  The following troubleshooting flow chart contains the fuel system diagnosis and repair procedures. Read the following warnings before servicing the fuel system:
―  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 [MZR 1.8, MZR 2.0, MZR 2.5].) (See AFTER SERVICE PRECAUTION [MZR 1.8, MZR 2.0, MZR 2.5].)
Caution
•  Disconnecting/connecting the quick release connector without cleaning it may 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.

Diagnostic procedure

STEP

INSPECTION

RESULTS

ACTION
1
Access the ECT PID using the M-MDS.
(See ON-BOARD DIAGNOSTIC TEST [MZR 1.8, MZR 2.0, MZR 2.5].)
Verify the ECT PID value is less than 116 °C {241 °F} during driving.
Is the ECT PID value 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 [MZR 1.8, MZR 2.0, MZR 2.5].)
2
Caution
•  While performing this step, always operate the vehicle in a safe and lawful manner.
•  When the M-MDS is used to observe monitor system status while driving, be sure to have another technician with you, or record the data in the M-MDS using the PID/DATA MONITOR AND RECORD capturing function and inspect later.
Access the IAT and MAF PIDs using the M-MDS.
(See ON-BOARD DIAGNOSTIC TEST [MZR 1.8, MZR 2.0, MZR 2.5].)
Do the PIDs indicate the correct values under the trouble condition?
(See PCM INSPECTION [MZR 1.8, MZR 2.0, MZR 2.5].)
Yes
Go to the next step.
No
IAT PID is not specified:
•  Inspect the IAT sensor.
MAF PID is not specified:
•  Inspect the MAF sensor.
Repair or replace the malfunctioning part according to the inspection results.
3
Perform the PCM DTC inspection using the M-MDS.
(See ON-BOARD DIAGNOSTIC TEST [MZR 1.8, MZR 2.0, MZR 2.5].)
Are any DTCs present?
Yes
Go to the applicable DTC inspection.
(See DTC TABLE [MZR 1.8, MZR 2.0, MZR 2.5].)
No
Go to the next step.
4
Inspect the engine compression.
(See COMPRESSION INSPECTION [MZR 1.8, MZR 2.0, MZR 2.5].)
Is there any malfunction?
Yes
Repair or replace the malfunctioning part according to the inspection results.
No
Go to the next step.
5
Inspect the fuel line pressure.
(See FUEL LINE PRESSURE INSPECTION [MZR 1.8, MZR 2.0, MZR 2.5].)
Is there any malfunction?
Yes
Zero or low:
•  Inspect the fuel pump relay and the fuel pump circuit.
•  Inspect the fuel line for clogging.
―  If there is any malfunction:
•  Repair or replace the malfunctioning part according to the inspection results.
―  If there is no malfunction:
•  Replace the fuel pump unit.
High:
•  Replace the fuel pump unit.
No
Go to the next step.
6
Inspect the KS.
(See KNOCK SENSOR (KS) INSPECTION [MZR 1.8, MZR 2.0, MZR 2.5].)
Is there any malfunction?
Yes
Replace the KS.
(See KNOCK SENSOR (KS) REMOVAL/INSTALLATION [MZR 1.8, MZR 2.0, MZR 2.5].)
No
Inspect the ignition timing.
(See ENGINE TUNE-UP [MZR 1.8, MZR 2.0, MZR 2.5].)
Repair or replace the malfunctioning part according to the inspection results.
7
Verify test results.
•  If normal, return to the diagnostic index to service any additional symptoms.
•  If the malfunction remains, inspect the related Service Information and perform the repair or diagnosis.
―  If the vehicle is repaired, troubleshooting is completed.
―  If the vehicle is not repaired or additional diagnostic information is not available, reprogram the PCM if a later calibration is available. Retest.