DTC Troubleshooting: P0172 (2.0L Engine): Inspection

Fuel Pressure Inspection (Low Pressure Side) 

Test Procedure 

• Procedure
• • -

    Do the fuel pressure test - Refer to: Fuel Pressure Test(2.0L Engine) or Fuel Pressure Test(3.0L Engine) or Fuel Pressure Relieving .

• Normal Conditions
• • -

    The fuel pressure is within the specified value - Refer to: Fuel Pressure Test(2.0L Engine) or Fuel Pressure Test(3.0L Engine) or Fuel Pressure Relieving during the HDS [AF FB (ST Fuel Trim)] is less than 0.79.

Results 

• If it is abnormal, there is a problem with the fuel tank unit or the fuel pump circuit. Follow the result of the fuel pressure test - Refer to: Fuel Pressure Test(2.0L Engine) or Fuel Pressure Test(3.0L Engine) or Fuel Pressure Relieving .

Fuel Pressure Inspection (High Pressure Side) 

Test Procedure 

• Procedure
• • Start the engine. Hold the engine speed at 3, 00 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 - Refer to: DTC Troubleshooting: P0087(2.0L Engine) or DTC Troubleshooting: P0087(3.0L Engine) and P0088 - Refer to: DTC Troubleshooting: P0088(3.0L Engine) or DTC Troubleshooting: P0088(2.0L Engine) .

MAF Sensor Functional Inspection 

Test Procedure 

• Procedure

• Start the engine, and let it idle.
• Make sure the following conditions are met:

  HDS [ECT Sensor 1] above 158 deg.F (70 deg.C)

  Transmission in P or N

  All engine and electrical loads turned off

• Monitor the HDS [Engine Speed] and hold the engine speed at 2, 00 rpm for 30 seconds.
• Confirm the HDS [MAF Sensor] while holding the engine speed at 2, 00 rpm.

• Normal Conditions
• • -

    The HDS [MAF Sensor] value is between 7.6 g/s and 10.6 g/s  .

Results 

• If it is abnormal, there is a problem with MAF sensor/IAT sensor 1.

Engine Oil (Fuel Contamination) Inspection 

Test Procedure 

• Procedure
• • Start the engine, then let it idle.
  • Gently pinch the PCV hose (A).
  • Confirm the HDS [AF FB (ST Fuel Trim)].

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

• Normal Conditions
• • -

    The HDS [AF FB (ST Fuel Trim] value is less than 0.79  .

Results 

• If it is abnormal, there is a problem the cause of the contaminated oil (faulty injectors, etc.), then replace the engine oil and oil filter.

EVAP Canister Purge Valve Inspection 

Test Procedure 

• Preparation
• • -

    EVAP canister purge valve 2P connector: disconnected

• Procedure
• • Disconnect the vacuum hose (purge line) (A) from the EVAP canister purge valve (B) in the engine compartment, then connect the vacuum pump/gauge, 0-30 inHg (C), to the EVAP canister purge valve as shown.
  • Start the engine.

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

• Normal Conditions
• • -

    Vacuum is not indicated.

Results 

• If it is abnormal, there is a problem with the EVAP canister purge valve.
  NOTE: When the climate is warm, fuel vapor from the canister line to the fuel tank enters intake manifold, enriching mixture (excessively rich), causing the engine to stall in some cases.

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.