Caution / Notice / Hint

HINT: 

• DTC P1603
  • In contrast to normal malfunction diagnosis for components, circuits and systems, DTC P1603 is used to determine the malfunctioning area from the problem symptoms and Freeze Frame Data when the user mentions problems such as engine stall.

    As this DTC can be stored as a result of certain user actions, even if the DTC is output, if the customer makes no mention of problems, clear the DTC without performing any troubleshooting and return the vehicle to the customer.

  • As DTCs may be stored when an Active Test or learning is performed, make sure to clear the DTCs before returning the vehicle to the customer.
  • DTCs related to engine stall problems may be detected due to operations performed by the user. The following are a few examples. Ask questions to the user about how the vehicle is operated and give advice as necessary.
    • Ran out of fuel
    • Rolled down on a slope and engine stalls (backed up in D, moved forward in R)
• CUSTOMER PROBLEM ANALYSIS
  • If any other DTCs are output, perform troubleshooting for those DTCs first.
  • Use any information from the customer problem analysis about the condition of the vehicle at the time when the problem occurred (how the engine stopped, conditions when the engine was restarted, etc.) as a reference.

    Symptom	Suspected Area
    Engine vibration occurs and engine stops	Abnormal mass air flow meter sub-assembly output due to existence of foreign matter Abnormal air fuel ratio due to malfunction of air fuel ratio sensor or heated oxygen sensor, air leaks in intake system or insufficient fuel supply
    Engine stops with no engine vibration	Ignition system, injection stoppage, high load from external parts
    Engine can be started with accelerator pedal depressed	Insufficient air volume
    Engine stalls or is difficult to start immediately after engine stalled, regardless of whether engine is cold or warm	Deposits in intake system or combustion chamber caught temporarily on intake or exhaust valve

• FREEZE FRAME DATA
  • Read Freeze Frame Data using the Techstream. Freeze Frame Data records engine conditions when a malfunction occurs. This information can be useful when troubleshooting.
  • When confirming the Freeze Frame Data, be sure to check all 5 sets of Freeze Frame Data.

    Refer to FREEZE FRAME DATA [01/2019 - 04/2020] , or refer to FREEZE FRAME DATA [04/2020 - 11/2022]

  • When confirming the Freeze Frame Data, if there are multiple items related to the cause of the malfunction, perform troubleshooting for all related items.
  • Try to operate the vehicle under the conditions recorded in the Freeze Frame Data which were present when the malfunction occurred. Confirm the data at this time and the data when the engine is idling (engine warmed up, no load, and shift lever in D or N) and compare this data with the Freeze Frame Data.
• PRECAUTIONS
  • Inspections take into account the fact that the malfunction may not have recurred and place emphasis on checking the vehicle conditions present at the time when the malfunction occurred.
  • When performing inspections, jiggle the relevant wire harnesses and connectors in an attempt to reproduce malfunctions that do not always occur.