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Home >> Mazda >> 2016 >> 6 Touring, Automatic Trans >> Repair and Diagnosis >> Engine Performance >> System >> Symptom Troubleshooting - Engine Control System >> No. 19 Exhaust Smoke >> Notes
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No. 19 Exhaust Smoke: Notes

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

White smoke (Water in combustion): 
  • Cooling system malfunction (coolant loss)
  • Engine internal coolant leakage

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
  • 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.
  • Fuel line spills and leakage are dangerous. Fuel can ignite and cause serious injury 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 [SKYACTIV-G 2.5] .) (See AFTER SERVICE PRECAUTION [SKYACTIV-G 2.5] .)
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 matter.
CAUTION:
  • Verify the malfunction symptom according to not only the PID value but also the symptom troubleshooting.