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Home >> Mazda >> 2017 >> CX-5 Grand Select, FWD >> Repair and Diagnosis >> External Pages >> Different car >> Section 145 (On-Board Diagnostic - Engine Control (2 Of 5)) >> DTC P0172; PCM Fuel TRIM SYSTEM TOO RICH >> Details On DTCs

Details On DTCs

WARNING: This page is about a different car, the 2017 Mazda 3. However, it is still accessible from the selected car via links, so may be relevant.
DETECTION CONDITION AND POSSIBLE CAUSE

DESCRIPTION Fuel trim system too rich
DETECTION CONDITION Determination conditions
  • Any one of the following conditions is met:
    • While the engine is idling or the vehicle is driven, the fuel feedback correction amount (SHRTFT1) is the threshold (-25 %) or less, and the fuel learning correction amount (LONGFT1) is the threshold (-15 %) or less for 10 s or more.
      • While the engine is idling or the vehicle is driven, the fuel feedback correction amount reaches the lower limit (-25 % or less) for 20 s or more.
Preconditions
  • Engine coolant temperature: 0-45 °C {32-113 °F}, 60 °C {140 °F} or more(1)
Malfunction determination period
  • 10 s or 20 s period
Drive cycle
  • 2
Self test type
  • CMDTC self test
Sensor used
  • A/F sensor
FAIL-SAFE FUNCTION
  • Not applicable
VEHICLE STATUS WHEN DTCs ARE OUTPUT
  • Illuminates check engine light.
POSSIBLE CAUSE
  • Erratic signal to PCM
    • ECT sensor No. 1 signal malfunction
    • MAF sensor signal malfunction
    • MAP sensor signal malfunction
    • IAT sensor No. 2 signal malfunction
    • Related connector or terminals malfunction
      • Related wiring harness malfunction
  • High-pressure side fuel delivery system malfunction
    • Fuel pressure sensor malfunction
    • Relief valve (built-into 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
      • High pressure fuel pump malfunction
  • Low-pressure side fuel delivery system malfunction
    • Fuel filter clogged (built-into fuel pump unit)
    • Low pressure side fuel line restriction (between fuel pump unit and high pressure fuel pump)
    • Fuel pump unit malfunction
    • Pressure regulator (built-into fuel pump unit) malfunction
      • Fuel pump control module malfunction
  • Fuel injector malfunction
    • Improper operation of fuel injector
      • Fuel injector related wiring harness malfunction
  • Improper operation of purge control system
    • Purge solenoid valve malfunction
      • Purge solenoid hoses improper connection
  • MAF sensor malfunction
  • MAP sensor malfunction
  • Improper operation of electric variable valve timing control system
    • Electric variable valve timing driver malfunction
    • Electric variable valve timing motor malfunction
      • Electric variable valve timing actuator malfunction
  • Improper operation of hydraulic variable valve timing control system
  • A/F sensor malfunction
    • A/F sensor loose
  • PCM malfunction
(1) Value can be verified by displaying PIDs using M-MDS