NO.8 MISFIRE [MZ-CD 1.6 (Y6) (EURO5 emission level)]

id0103e7854100

8

Misfire
DESCRIPTION
•  Engine misfire.
•  Engine misfire and glow indicator light is flashing.
POSSIBLE CAUSE
•  PCM DTC is detected.
•  Fuel tank fuel level low.
•  Air cleaner element restriction
•  Loose vacuum line(s)/vacuum connections
•  Loose intake-air system hose(s)/hose connections
•  Loose intake-air system tube(s)/tube connections
•  Coolant leakage
•  Incorrect or contaminated fuel in fuel tank
•  Electrical connector, wiring harness or component damaged
•  Loose installation fuel gauge sender unit
•  Engine operating temperature too high.
•  Air ingress into the fuel lines.
•  EGR valve incorrect base setting
•  Erratic signal to PCM
―  MAF sensor signal malfunction
―  ECT sensor signal malfunction
•  CKP sensor or pulse wheel malfunction
•  CMP sensor or pulse wheel malfunction
•  EGR valve incorrect operation.
•  Fuel injector malfunction
•  Supply pump malfunction
•  Low cylinder compression.
•  Worn or damaged valve(s), camshaft follower(s) or camshaft(s).
•  Excessive carbon build up in cylinder head and/or bore
•  PCM malfunction

Diagnostic procedure

STEP

INSPECTION

RESULTS

ACTION
1
VERIFY PCM DTC
•  Perform the PCM DTC inspection using the M-MDS.
•  Are any DTCs present?
Yes
Go to the applicable DTC inspection.
(See DTC TABLE [MZ-CD 1.6 (Y6) (EURO5 emission level)].)
No
Go to the next step.
2
VISUALLY INSPECT RELATED PART CONDITION
•  Visually inspect the following:
Mechanical:
―  Fuel level
―  Air cleaner element
―  Vacuum line(s)/vacuum connections
―  Hose(s)/hose connections
―  Tube(s)/tube connections
―  Fuel system leak(s) (Fuel filter, fuel supply line(s), fuel return line(s), high-pressure fuel supply line(s), fuel injectors, fuel rail, supply pump, fuel tank, fuel tank ventilation pipe, fuel tank filler pipe)
―  Contaminated fuel
Electrical:
―  Fuse(s)
―  Relay(s)
―  Loose or corroded connector(s) (PCM, sensor(s), switch(es))
―  Damaged or worn PCM, switch(es) and/or sensor(s)
―  Wiring harness
―   Fuel gauge sender unit installation
•  Is there any malfunction?
Yes
Repair or replace the malfunctioning part according to the inspection results.
Repeat Step 2.
No
Go to the next step.
3
CAUSE IS OVERHEATING
•  Is the engine overheating?
Yes
Go to the symptom troubleshooting “NO.11 COOLING SYSTEM CONCERNS-OVERHEATING”.
(See NO.11 COOLING SYSTEM CONCERNS-OVERHEATING [MZ-CD 1.6 (Y6) (EURO5 emission level)].)
No
Go to the next step.
4
DETERMINE IF MALFUNCTION CAUSE IS AIR INGRESS IN FUEL LINE OR OTHER
•  Perform the Fuel Line Air Bleeding.
•  Verify the symptom.
•  Is the symptom solved?
Yes
Troubleshooting is completed.
(Air ingress into the fuel line.)
No
Go to the next step.
5
DETERMINE IF MALFUNCTION CAUSE IS AIR INGRESS IN FUEL LINE OR OTHER
•  Perform the “EXHAUST GAS RECIRCULATION VALVE LEARNED VALUES RESET” and “INTAKE AIR THROTTLE VALVE LEARNED VALUES RESET”.
•  Verify the symptom.
•  Is the symptom solved?
Yes
Troubleshooting is completed.
(EGR valve base setting is incorrect.)
No
Go to the next step.
6
VERIFY CURRENT INPUT SIGNAL STATUS
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 following PIDs using the M-MDS:
―  MAF
―  ECT
•  Monitor the each PID while driving the vehicle.
•  Are all PIDs normal?
Yes
Go to the next step.
No
If the MAF PID is not specified:
•  Inspect the MAF sensor and related wiring harness.
If the ECT PID is not specified:
•  Inspect the ECT sensor and related wiring harness.
Repair or replace malfunctioning part.
7
VISUALLY INSPECT CKP SENSOR AND PULSE WHEEL
•  Visually inspect the CKP sensor and teeth of the crankshaft pulley.
•  Is there any malfunction?
Yes
Repair or replace the malfunctioning part as necessary.
No
Go to the next step.
8
VISUALLY INSPECT CMP SENSOR AND PULSE WHEEL
•  Visually inspect the CMP sensor and teeth of the camshaft pulley.
•  Is there any malfunction?
Yes
Repair or replace the malfunctioning part as necessary.
No
Go to the next step.
9
INSPECT FUEL INJECTOR
•  Inspect the fuel injector for each cylinder.
•  Are fuel injectors normal?
Yes
Go to the next step.
No
Replace the suspected fuel injector.
(See FUEL INJECTOR REMOVAL/INSTALLATION [MZ-CD 1.6 (Y6)].)
10
INSPECT EGR VALVE OPERATION
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 following PCM PIDs.
―  EGRP
―  SEGRP DSD
•  Monitor the each PID while driving the vehicle.
•  Are PIDs value changing according to driving conditions?
Yes
Go to the next step.
No
Inspect the EGR valve for stuck.
Clean or replace the EGR valve as necessary.
(See EGR VALVE REMOVAL/INSTALLATION [MZ-CD 1.6 (Y6)].)
11
INSPECT EGR COOLER BYPASS VALVE OPERATION
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 following PCM PIDs.
―  EGR_C_BP
―  EGR_C_BP_D
•  Monitor the each PID while driving the vehicle.
•  Are PIDs value changing according to driving conditions?
Yes
Go to the next step.
No
Inspect the EGR cooler bypass valve for stuck.
Clean or replace the EGR cooler bypass valve as necessary.
(See INTAKE-AIR SYSTEM REMOVAL/INSTALLATION [MZ-CD 1.6 (Y6)].)
12
DETERMINE IF MALFUNCTION CAUSE IS SUPPLY PUMP OR OTHER
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 following PID using the M-MDS:
―  FRP
―  FRP_DSD
―  FUEL_V_DSD
•  Monitor the each PID while driving the vehicle.
•  Are all PIDs normal?
Yes
Go to the next step.
No
Inspect the fuel pressure sensor and related wiring harness.
(See FUEL PRESSURE SENSOR INSPECTION [MZ-CD 1.6 (Y6) (EURO5 emission level)].)
•  If there is malfunction, repair or replace malfunctioning part.
•  If there is no malfunction, replace the supply pump.
(See SUPPLY PUMP REMOVAL/INSTALLATION [MZ-CD 1.6 (Y6)].)
13
INSPECT CYLINDER
•  Remove the cylinder head.
•  Visually inspect cylinder head and cylinder bore.
•  Is there any carbon or damaged part detected?
Yes
Clean the cylinder head as necessary.
Repair or replace the malfunctioning part according to the inspection results.
No
Replace the fuel.
(Poor fuel quality (e.g.: include water contamination, winter/summer blend))
•  Flush the fuel line as necessary.
14
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.