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Diagnostic Procedure

WARNING: This page is about a different variant/trim than selected.
SPARK PLUG CONDITION (VIN Y) DIAGNOSTIC PROCEDURE

Step Inspection Results Action
1 VERIFY SPARK PLUG CONDITION  Yes Specific plug is wet or covered with carbon: 
  • Go to the next step.

Specific plug looks grayish white: 
  • Go to Step 7.

All plugs are wet or covered with carbon: 
  • Go to Step 9.

All plugs look grayish white: 
  • Go to Step 16.
No Complete the symptom troubleshooting.
2 DETERMINE IF MALFUNCTION CAUSE IS ENGINE OIL LOSS OR OTHER 
  • Are the spark plugs wet/covered with carbon from the engine oil?
 Yes Inspect all areas related to oil, working up and down.
  • If there is any malfunction:
    • Repair or replace the malfunctioning location and perform the repair completion verification 1.
No Go to the next step.
3 VERIFY SPARK PLUG FOR MALFUNCTION 
  • Inspect the spark plugs for the following: (Refer to SPARK PLUG INSPECTION (VIN Y) .)
    • Air gap
    • Cracked insulator
    • Worn electrode
    • Heat range
  • Is there any malfunction?
 Yes Replace the spark plug and perform the repair completion verification 1.
(Refer to SPARK PLUG REMOVAL/INSTALLATION (VIN Y) .)
No Go to the next step.
4 INSPECT ENGINE COMPRESSION 
  • Inspect the compression pressure at the suspected cylinder. (Refer to COMPRESSION INSPECTION (VIN Y) .)
  • Are compression pressures within specification?
 Yes Go to the next step.
No Repair or replace the malfunctioning location and perform the repair completion verification 1.
5 INSPECT IGNITION SYSTEM OPERATION  Yes Go to the next step.
No Repair or replace the malfunctioning location and perform the repair completion verification 1.
6 INSPECT FUEL LINE PRESSURE 
  • Inspect the fuel line pressure. (Refer to FUEL LINE PRESSURE INSPECTION (VIN Y) .)
  • Is the low side fuel pressure within specification?

    Specification: 

  • 475-555 kPa {4.85-5.65 kgf/cm 2 , 68.9 -80.4 psi}
 Yes Inspect the fuel injector for the following:
  • Injection volume
  • Fuel leakage
  • Open or short circuit in injector (Refer to FUEL INJECTOR INSPECTION (VIN Y) .)
    • If there is any malfunction:
      • Repair or replace the malfunctioning location and perform the repair completion verification 1.
No Zero or low: 
  • Inspect the fuel pump relay and the fuel pump circuit. (Refer to RELAY INSPECTION .)
  • Inspect the fuel line for restriction.
    • If there is any malfunction:
      • Repair or replace the malfunctioning location and perform the repair completion verification 1.
    • If there is no malfunction:

High: 
7 VERIFY SPARK PLUG FOR MALFUNCTION 
  • Inspect the spark plug for the following:
    • Air gap
    • Heat range
  • Is there any malfunction?
 Yes Replace the spark plug and perform the repair completion verification 1.
(Refer to SPARK PLUG REMOVAL/INSTALLATION (VIN Y) .)
No Go to the next step.
8 INSPECT FUEL INJECTOR OPERATION  Yes Go to the next step.
No Repair or replace the malfunctioning location and perform the repair completion verification 1.
9 VERIFY AIR CLEANER ELEMENT FOR MALFUNCTION  Yes Go to the next step.
No Repair or replace the malfunctioning location and perform the repair completion verification 1.
(Refer to AIR CLEANER ELEMENT REMOVAL/INSTALLATION (VIN Y) .)
10 VERIFY CURRENT INPUT SIGNAL STATUS 
  • Access the following PIDs using the M-MDS:

    PCM: 

    • ECT
    • ECT_VOLT
    • ECT2
    • ECT2_VOLT
    • MAF
    • A/F_SEN_CUR (When engine can be started)
    • HO2S_OUT_VOLT (When engine can be started)
  • Are the PIDs normal? (See PID/DATA MONITOR TABLE [PCM (VIN Y)] .)
 Yes Go to the next step.
No ECT, ECT_VOLT PIDs are not as specified: 
ECT2, ECT2_VOLT PIDs are not as specified: 
MAF PID is not as specified: 
A/F_SEN_CUR PID is not as specified: 
HO2S_OUT_VOLT PID is not as specified: 
  • Inspect for an intermittent open circuit of the HO2S and the related wiring harness.
  • Inspect the HO2S. (Refer to HEATED OXYGEN SENSOR (HO2S) INSPECTION (VIN Y) .)

    Repair or replace the malfunctioning location and perform the repair completion verification 1.
11 INSPECT PURGE CONTROL SYSTEM OPERATION  Yes Repair or replace the malfunctioning location and perform the repair completion verification 1.
No Go to the next step.
12 INSPECT IGNITION SYSTEM OPERATION  Yes Go to the next step.
No Repair or replace the malfunctioning location and perform the repair completion verification 1.
13 INSPECT ENGINE COMPRESSION  Yes Go to the next step.
No Repair or replace the malfunctioning location and perform the repair completion verification 1.
14 INSPECT EGR VALVE FOR MALFUNCTION  Yes Go to the next step.
No Repair or replace the malfunctioning location and perform the repair completion verification 1.
(Refer to EGR VALVE REMOVAL/INSTALLATION (VIN Y) .)
15 INSPECT ENGINE COMPRESSION 
  • Inspect the fuel line pressure. (Refer to FUEL LINE PRESSURE INSPECTION (VIN Y) .)
  • Is the low side fuel pressure within specification?

    Specification: 

  • 475-555 kPa {4.85-5.65 kgf/cm 2 , 68.9-80.4 psi}
 Yes Visually inspect for deformed exhaust system parts.
  • If there is any malfunction:
    • Repair or replace the malfunctioning location and perform the repair completion verification 1.
No Zero or low: 
  • Inspect the fuel pump relay and the fuel pump circuit. (Refer to RELAY INSPECTION .)
  • Inspect the fuel line for restriction.
    • If there is any malfunction:
      • Repair or replace the malfunctioning location and perform the repair completion verification 1.
    • If there is no malfunction:

High: 
16 VERIFY CURRENT INPUT SIGNAL STATUS 
  • Access the following PIDs using the M-MDS:

    PCM: 

    • ECT
    • ECT_VOLT
    • ECT2
    • ECT2_VOLT
    • MAF
    • A/F_SEN_CUR (When engine can be started)
    • HO2S_OUT_VOLT (When engine can be started)
  • Are the PIDs normal? (See PID/DATA MONITOR TABLE [PCM (VIN Y)] .)
 Yes Go to the next step.
No ECT, ECT_VOLT PIDs are not as specified: 
ECT2, ECT2_VOLT PIDs are not as specified: 
MAF PID is not as specified: 
A/F_SEN_CUR PID is not as specified: 
HO2S_OUT_VOLT PID is not as specified: 
  • Inspect for an intermittent open circuit of the HO2S and the related wiring harness.
  • Inspect the HO2S. (Refer to HEATED OXYGEN SENSOR (HO2S) INSPECTION (VIN Y) .)

    Repair or replace the malfunctioning location and perform the repair completion verification 1.
17 INSPECT INTAKE-AIR SYSTEM FOR AIR LEAKAGE 
  • If the engine cannot be started:
    • Inspect for leakage in intake-air system.
  • If the engine can be started:
  • Is there any leakage?
 Yes Repair or replace the malfunctioning location and perform the repair completion verification 1.
No Go to the next step.
18 INSPECT EGR VALVE FOR MALFUNCTION  Yes Go to the next step.
No Repair or replace the malfunctioning location and perform the repair completion verification 1.
(Refer to EGR VALVE REMOVAL/INSTALLATION (VIN Y) .)
19 INSPECT FUEL LINE PRESSURE 
  • Inspect the fuel line pressure. (Refer to FUEL LINE PRESSURE INSPECTION (VIN Y) .)
  • Is the low side fuel pressure within specification?

    Specification: 

  • 545-695 kPa {5.56-7.08 kgf/cm 2 , 79.1-100.0 psi}
 Yes Inspect the PCM ground condition.
  • If there is any malfunction:
    • Repair or replace the malfunctioning location and perform the repair completion verification 1.
No Zero or low: 
  • Inspect the fuel pump relay and the fuel pump circuit. (Refer to RELAY INSPECTION .)
  • Inspect the fuel line for restriction.
    • If there is any malfunction:
      • Repair or replace the malfunctioning location and perform the repair completion verification 1.
    • If there is no malfunction:

High: 
Repair completion verification 1 VERIFY THAT VEHICLE IS REPAIRED 
  • Install/connect the part removed/disconnected during the troubleshooting procedure.
  • Has the malfunction symptom been eliminated?
 Yes Complete the symptom troubleshooting. (Explain contents of repair to customer)
No Refer to the controller area network (CAN) malfunction diagnosis flow to inspect for a CAN communication error.
(See MALFUNCTION DIAGNOSIS FLOW [CONTROLLER AREA NETWORK (CAN)] .)
  • If the CAN communication is normal, perform the diagnosis from Step 1.
    • If the malfunction recurs, go to the next step.
Repair completion verification 2 VERIFY IF MALFUNCTION IS CAUSED BY NOT PERFORMING PCM REPROGRAMMING 
  • Verify repair information and verify that there is a new calibration in the PCM.
  • Is there a new calibration in the PCM?
 Yes Perform the PCM reprogramming and verify if the malfunction symptom was corrected.
No Replace the PCM.
(Refer to PCM REMOVAL/INSTALLATION (VIN Y) .)
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