SFI SYSTEM, Diagnostic DTC:P122F

DTC Code DTC Name
P122F High Pressure Fuel Pump Boost Malfunction(High Temperature)

DESCRIPTION

If there is a problem in increasing the fuel pressure with the fuel pump (for high pressure) when starting the engine from an engine stop after driving the vehicle under heavy load at high temperatures, a DTC is output. Freeze frame data, which records conditions present at the time the DTC was stored, can be confirmed using the GTS. By confirming whether there were problems with drivability due to a problem in increasing the fuel pressure improves serviceability.

DTC No. DTC Detection Condition
P122F

All conditions are met and the fuel pressure (for high pressure) does not follow the target fuel pressure (for high pressure) for 3.5 seconds or more:


  • (a) Restarting the engine at high temperatures (coolant temperature is 95°C (203°F) or higher and intake air temperature is 75°C (167°F) or higher), or restarting the engine (at a coolant temperature of 98°C (208°F) or higher and intake air temperature of 20°C (68°F) or higher) after driving with a heavy load at high temperatures*.

  • (b) The engine is running due to an initial start.

  • (c) The fuel pump (for high pressure) is operating at maximum output.

*: The coolant temperature was 98°C (208°F) or higher and the estimated engine oil temperature was 98°C (208°F) or higher the last time the power switch was turned off.

INSPECTION PROCEDURE

Tech Tips


  • If other DTCs are output, perform troubleshooting for the relevant DTCs first.

  • The following troubleshooting procedure is an example of one method, as DTC P122F is different than conventional troubleshooting DTCs.

  • DTC P122F differs from conventional troubleshooting DTCs for parts, circuits and systems. This DTC is used to determine the malfunctioning part from the malfunction symptoms and freeze frame data when the customer mentions drivability problems when starting the engine after the engine was hot. Even if a DTC is output, when there is no mention of a problem from the customer, do not perform any procedures, clear the DTCs and return the vehicle to the customer, as this DTC may be output due to the way the vehicle was operated by the customer.

PROCEDURE


  1. CHECK ANY OTHER DTCS OUTPUT (IN ADDITION TO DTC P122F)


    1. Connect the GTS to the DLC3.

    2. Turn the power switch on (IG).

    3. Turn the GTS on.

    4. Enter the following menus: Powertrain / Engine and ECT / Trouble Codes.

    5. Read the DTCs.

      Result
      Result Proceed to
      DTC P122F is output A
      DTC P122F and other DTCs are output B

      Tech Tips

      If any DTCs other than P122F are output, troubleshoot those DTCs first.


    B

    GO TO DTC CHART Click here

    A

  2. CHECK FREEZE FRAME DATA


    1. Connect the GTS to the DLC3.

    2. Turn the power switch on (IG).

    3. Turn the GTS on.

    4. Enter the following menus: Powertrain / Engine and ECT / Trouble Codes.

    5. Confirm the freeze frame data and check the vehicle conditions at the time the DTC was stored.

      Confirmation Item
      Coolant Temp
      Initial Engine Coolant Temp
      Engine Speed
      Intake Air
      Initial Intake Air Temp
      Engine Oil Temperature
      Previous Trip Coolant Temp
      Previous Trip Eng Oil Temp
      Fuel Press
      Fuel Pressure Target Value
      Fuel Pump Duty (D4)
      HP FP Discharge Rate
      Injection Way
      Throttle Position
      ISC Flow
      ISC Position
      ISC Feedback Value
      ISC Learning Value
      Electric Load Feedback Value
      MAP
      Calculate Load
      Electric Fan Motor

    6. Use this information to perform a simulation test.

    7. Compare the "Normal Condition" information in the Data List table (reference values) with the freeze frame data listed above and with the simulation test results to determine the problem cause.

      Result
      Result Proceed to
      The problem cause can be determined A
      The problem cause cannot be determined B

    B

    CHECK INTERMITTENT PROBLEMS Click here

    A

    REPAIR OR REPLACE MALFUNCTIONING PARTS