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Home >> Mazda >> 2021 >> CX-9 Signature >> Repair and Diagnosis >> Engine Performance >> System >> Symptom Troubleshooting - Engine >> No. 19 Exhaust Smoke >> Notes
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No. 19 Exhaust Smoke: Notes

NO. 19 EXHAUST SMOKE (SKYACTIV-G 2.5T) DESCRIPTION AND POSSIBLE CAUSE

19 EXHAUST SMOKE
DESCRIPTION
  • Blue, black, or white smoke from exhaust system.
POSSIBLE CAUSE Blue smoke (Burning oil):
  • PCV valve malfunction
  • Engine internal oil leakage
  • Oil leakage at the compressor or turbine end of the turbocharger White smoke (Water in combustion):
  • Cooling system malfunction (coolant loss)
  • Engine internal coolant leakage
  • Coolant leakage at the compressor or the turbine end of the turbocharger Black smoke (Rich fuel mixture):
  • Erratic signal to PCM
    • APP sensor or related circuit malfunction
    • ECT sensor No. 1 or related circuit malfunction
    • IAT sensor No. 1 (integrated in MAF sensor/IAT sensor No. 1) or related circuit malfunction
    • MAF sensor or related circuit malfunction
    • MAP sensor or related circuit malfunction
    • A/F sensor or related circuit malfunction
    • HO2S or related circuit malfunction
    • TP sensor or related circuit malfunction
    • Boost pressure sensor signal
      • Boost air temperature sensor signal
  • Improper fuel injection timing and amount
  • Air cleaner restriction
  • Intake-air system is collapsed or restricted
  • Leakage at engine intake manifold and/or exhaust manifold
  • Inadequate/Excessive fuel pressure
    • Fuel pressure sensor malfunction
    • High pressure fuel pump malfunction
    • Spill valve control solenoid valve control circuit malfunction (damage to driver in PCM caused by short circuit to ground system)
    • Spill valve control solenoid valve (built-into high pressure fuel pump) malfunction
    • Relief valve (built-into high pressure fuel pump) malfunction
    • Fuel line restricted or clogged
      • Fuel pump unit malfunction
  • Ignition system malfunction
  • Improper engine compression
  • Improper intake valve timing
  • Improper exhaust valve timing
  • Injector driver (built-into 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.
      • Highly pressurized fuel may spray out if the fuel line is cut. Due to the following dangers occurring with a fuel spray, always complete the "Fuel Line Safety Procedure" to prevent the fuel from spraying. (See BEFORE SERVICE PRECAUTION [SKYACTIV-G 2.5T] .)
  • Fuel may cause irritation if it comes in contact with skin and eyes.
    • If fuel ignites and causes a fire, it may lead to serious injury or death, and damage to property and facilities.
    CAUTION:
    • Disconnecting/connecting the quick release connector without cleaning it may possibly cause damage to the fuel pipe and quick release connector. Always clean the quick release connector joint area before disconnecting/connecting, and make sure that it is free of foreign material.