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Diagnostic Procedure

WARNING: This page is about a different car, the 2020 Mazda CX-30. However, it is still accessible from the selected car via links, so may be relevant.
EXHAUST SMOKE (SKYACTIV-G, US) DIAGNOSTIC PROCEDURE

Step Inspection Results Action
1 VERIFY EXHAUST COLOR
  • What color is smoke coming from the exhaust system?
 Blue Burning oil is indicated.
  • Go to the next step.
White Water in combustion is indicated.
  • Go to Step 4.
Black Rich fuel mixture is indicated.
  • Go to Step 5.
2 INSPECT PCV VALVE FOR MALFUNCTION
 Yes Go to the next step.
No Repair or replace the malfunctioning location and perform the repair completion verification.
(See POSITIVE CRANKCASE VENTILATION (PCV) VALVE REMOVAL/INSTALLATION [SKYACTIV-G (VIN M (US))] .)
(See POSITIVE CRANKCASE VENTILATION (PCV) VALVE REMOVAL/INSTALLATION [SKYACTIV-G (VIN L (US))] .)
3 INSPECT ENGINE INTERNAL PARTS
  • Inspect for the following engine internal parts:
    • Damaged valve guide, stems or valve seals
    • Blocked oil drain passage in cylinder head
    • Piston ring is not seated, seized or worn
      • Damage cylinder bore
  • Is there any malfunction?
 Yes Repair or replace the malfunctioning location and perform the repair completion verification.
No Engine internal parts are normal.
  • If other driveability symptoms are present:
4 INSPECT ENGINE FOR ENGINE COOLANT LEAKAGE
 Yes Inspect the following:
  • Cylinder head gasket leakage
  • Intake manifold gasket leakage
  • Cracked or porous engine block

If there is any malfunction:
  • Repair or replace the malfunctioning location and perform the repair completion verification.

If there is no malfunction:
  • If other driveability symptoms are present:
No Repair or replace the malfunctioning location and perform the repair completion verification.
5 VERIFY CURRENT INPUT SIGNAL STATUS
WARNING:
  • 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: (See PID/DATA MONITOR INSPECTION .)
    • APP1
    • APP2
    • ECT
    • ECT_VOLT
    • ECT2
    • ECT2_VOLT
    • IAT
    • MAF
    • MAP
    • MAP_VOLT
    • TP_RELAT
    • A/F_SEN_CUR
    • HO2S_OUT_VOLT
    • SHRT_FUEL_TRIM
      • LONG_FUEL_TRIM
  • Monitor the PIDs under the black smoke appeared engine condition.
  • Do the PIDs indicate normal according to engine conditions? (See PID/DATA MONITOR TABLE [PCM (SKYACTIV-G (US))] .)
 Yes Go to the next step.
No APP1, APP2 PIDs are not as specified:

ECT, ECT_VOLT, ECT2, ECT2_VOLT PIDs are not as specified:

IAT PID is not as specified:

MAF PID is not as specified:

MAP, MAP_VOLT PIDs are not as specified:

TP_RELAT PID is not as specified:

A/F_SEN_CUR, SHRT_FUEL_TRIM, LONG_FUEL_TRIM PIDs are not as specified:

HO2S_OUT_VOLT PID is not as specified:

Repair or replace the malfunctioning location.
6 INSPECT FUEL INJECTOR OPERATION
 Yes Go to the next step.
No Repair or replace the malfunctioning location and perform the repair completion verification.
7 INSPECT INTAKE AIR SYSTEM
  • Inspect the following for intake-air system:
    • Air cleaner restriction
    • Collapsed or restricted air hose
      • Leakage at engine intake manifold
  • Is there any malfunction?
 Yes Repair or replace the malfunctioning location and perform the repair completion verification.
No Go to the next step.
8 INSPECT EXHAUST SYSTEM FOR LEAKAGE
  • Visually inspect for exhaust gas leakage from exhaust manifold.
  • Is there any leakage?
 Yes Repair or replace the malfunctioning location and perform the repair completion verification.
No Go to the next step.
9 INSPECT FUEL PRESSURE (HIGH-SIDE)
  • Start the engine and warm it up completely.
  • Access the FUEL_PRES PID using the M-MDS at idle. (See PID/DATA MONITOR INSPECTION .)
  • Is the FUEL_PRES PID value within specification?

Specification:
  • Approx. 10 MPa {102 kgf/cm2 , 1450 psi}
 Yes Go to Step 13.
No Lower than specification:
10 DETERMINE IF MALFUNCTION CAUSE IS FUEL PRESSURE SENSOR OR HIGH PRESSURE FUEL PUMP
  • Is the vehicle acceleration performance normal?
 Yes Go to the next step.
No Go to Step 12.
11 INSPECT FUEL PRESSURE SENSOR FOR MALFUNCTION
 Yes Go to Step 13.
No Replace the fuel distributor and perform the repair completion verification.
(See FUEL INJECTOR REMOVAL/INSTALLATION [SKYACTIV-G (VIN M (US))] .)
(See FUEL INJECTOR REMOVAL/INSTALLATION [SKYACTIV-G (VIN L (US))] .)
12 INSPECT SPILL VALVE CONTROL SOLENOID VALVE CONTROL CIRCUIT FOR SHORT TO GROUND
  • Inspect the applicable circuit for a short to ground. (See CIRCUIT INSPECTION .)
  • Is the circuit normal?
 Yes Replace the high pressure fuel pump and perform the repair completion verification.
(See HIGH PRESSURE FUEL PUMP REMOVAL/INSTALLATION [SKYACTIV-G (VIN M (US))] .)
(See HIGH PRESSURE FUEL PUMP REMOVAL/INSTALLATION [SKYACTIV-G (VIN L (US))] .)
No Repair or replace the malfunctioning location and perform the repair completion verification.
13 INSPECT FUEL PRESSURE (LOW-SIDE)

Specification:
  • 475-555 kPa {4.85-5.65 kgf/cm2 , 68.9-80.4 psi}
 Yes Go to the next step.
No Inspect the following:
14 INSPECT IGNITION SYSTEM OPERATION
NOTE:
  • Because the malfunction may have been resolved by removing the carbon adhered to the spark plug during the spark inspection for the spark plug, verify that the repairs have been completed.
 Yes Go to the next step.
No Repair or replace the malfunctioning location and perform the repair completion verification.
15 INSPECT ENGINE COMPRESSION
 Yes Injector driver malfunction.

If the problem remains, overhaul the engine and perform the repair completion verification.
No Inspect the following:
  • Damaged valve seat
  • Worn valve stem and valve guide
  • Worn or stuck piston ring
  • Worn piston, piston ring or cylinder
  • Improper intake valve timing
  • Improper exhaust valve timing

Repair or replace the malfunctioning location and perform the repair completion verification.
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 CONTROLLER AREA NETWORK (CAN) MALFUNCTION DIAGNOSIS FLOW [(US)] .)
  • 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.
(See PCM REMOVAL/INSTALLATION [SKYACTIV-G (VIN M (US))] .)
(See PCM REMOVAL/INSTALLATION [SKYACTIV-G (VIN L (US))] .)
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