DTC P0171, P0174: Inspection

MAF Sensor Visual Inspection 

Test Procedure 

• Preparation
  • MAF sensor/IAT sensor: removed

• Procedure
  • Visually check for lint, bugs, and other foreign objects in the MAF sensor.

• Normal Conditions
  • There is no lint, bugs, or other foreign objects in the MAF sensor.

Results 

• If it is abnormal, there is a problem with MAF sensor/IAT sensor.

MAF Sensor Functional Inspection 

Test Procedure 

• Procedure
  • Start the engine, and let it idle.
  • Make sure the following conditions are met:
    1. HDS [ECT Sensor 1] above 158°F (70°C)
    2. Transmission in P or N
    3. All engine and electrical loads turned off
  • Monitor the HDS [Engine Speed] and hold the engine speed at 2,500 rpm for 30 seconds.
  • Confirm the HDS [MAF Sensor] while holding the engine speed at 2,500 rpm.

• Normal Conditions
  • The HDS [MAF Sensor] value is between 11.5 g/s and 16.1 g/s  .

Results 

• If it is abnormal, there is a problem with MAF sensor/IAT sensor.

Intake Air System Inspection (Leakage) 

Test Procedure 

• Procedure
  • Check for leakage on the intake air system components between the air cleaner housing and the intake manifold.

    NOTE:  Possible major leak factors are the following:

    * Poor connections on the hose and pipe joints

    * Misinstalled, deformed, or damaged components, parts (hose, tube ,pipe), or devices (sensor, etc)

    * Locations where gaskets are used

• Normal Conditions
  • There are no leaks.

Results 

• If it is abnormal, there is a problem with the intake air system.

PCV System 1 Inspection (Leakage) 

Test Procedure 

• Procedure
  • Check for leakage from the PCV system components (A).

    NOTE:  Possible major leak factors are the following:

    * Poor connections on the hose and pipe joints

    * Misinstalled, deformed, or damaged components, parts (hose, tube ,pipe), or devices (sensor, etc)

    * Locations where gaskets are used

Courtesy of HONDA, U.S.A., INC.

• Normal Conditions
  • There are no leaks.

Results 

• If it is abnormal, there is a problem with PCV system 1.

PCV System 2 Inspection (Leakage) 

Test Procedure 

• Procedure
  • Check for leakage from the engine assembly and the PCV system components.

    * PCV valve (A)

    * PCV hose (B)

    * Oil filler cap (C)

    * Dipstick (D)

    NOTE:  Possible major leak factors are the following:

    * Poor connections on the hose and pipe joints

    * Misinstalled, deformed, or damaged components, parts (hose, tube ,pipe), or devices (sensor, etc)

    * Locations where gaskets are used

Courtesy of HONDA, U.S.A., INC.

• Normal Conditions
  • There are no leaks.

Results 

• If it is abnormal, there is a problem with PCV system 2.

EVAP Purge System Inspection (Leakage) 

Test Procedure 

• Procedure
  • Check for leakage from the EVAP purge system components (A).

    NOTE:  Possible major leak factors are the following:

    * Poor connections on the hose and pipe joints

    * Misinstalled, deformed, or damaged components, parts (hose, tube ,pipe), or devices (sensor, etc)

    * Locations where gaskets are used

Courtesy of HONDA, U.S.A., INC.

• Normal Conditions
  • There are no leaks.

Results 

• If it is abnormal, there is a problem with the EVAP purge system.

Fuel Pressure Inspection (High Pressure Side) 

Test Procedure 

• Procedure
  • Start the engine. Hold the engine speed at 3,000 rpm without load (in P or N) until the radiator fan comes on, then let it idle.
  • Do the HDS [DI FUEL PRESSURE TEST].

• Normal Conditions
  • The test result is NORMAL.

Results 

• If it is abnormal, do the troubleshooting for DTC P0087  and P0088 .

Fuel Inspection 

NOTE:  Since there is no direct method to test the inspection item, troubleshooting is performed using a known-good component.

Test Procedure 

• Install a known-good fuel and attempt to reproduce the failure.

  NOTE:  Drain the existing fuel, refill with known-good fuel and try it.

Results 

• If the failure is reproduced, there is a problem with other related components.
• If the symptom/DTC goes away, the fuel must be faulty.

A/F Sensor (Sensor 1) Inspection 

NOTE:  Since there is no direct method to test the inspection item, troubleshooting is performed using a known-good component.

Test Procedure 

• Install a known-good A/F sensor (Sensor 1) and attempt to reproduce the failure.

Results 

• If the failure is reproduced, there is a problem with other related components.
• If the symptom/DTC goes away, the A/F sensor (Sensor 1) must be faulty.

Injector Inspection 

NOTE:  Since there is no direct method to test the inspection item, troubleshooting is performed using a known-good component.

Test Procedure 

• Install a known-good injector and attempt to reproduce the failure.

Results 

• If the failure is reproduced, there is a problem with other related components.
• If the symptom/DTC goes away, the injector must be faulty.

PCM Inspection 

Test Procedure 

• If the other inspection item(s) indicated a normal condition, then it is determined that the remaining PCM is the cause.

Results 

• There is a problem with the PCM.