DTC P0171: Inspection

MAF Sensor Visual Inspection 

Test Procedure 

• Preparation
  1. -

     MAF sensor/IAT sensor: removed

• Procedure
  1. -

     Visually check for lints, bugs, and other foreign objects in the MAF sensor.

• Normal Conditions
  1. -

     There is no lints, bugs, or other foreign objects in the MAF sensor.

Results 

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

MAF Sensor Functional Inspection 

Test Procedure 

• Procedure

1. Start the engine, and let it idle.
2. 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

3. Monitor the HDS [Engine Speed] and hold the engine speed at 2,500 rpm for 30 seconds.
4. Confirm the HDS [MAF Sensor] while holding the engine speed at 2,500 rpm.

• Normal Conditions
  1. -

     The HDS [MAF Sensor] value is between 6.5 g/s and 9.1 g/s  .

Results 

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

Intake Air System Inspection (Leakage) 

Test Procedure 

• Procedure
  1. -

     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
  1. -

     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
  1. -

     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

• Normal Conditions
  1. -

     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
  1. -

     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
  1. -

     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
  1. -

     There are no leaks.

Results 

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

Fuel Inspection 

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 

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 

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.