SFI SYSTEM, Diagnostic DTC:P0418

DTC Code DTC Name
P0418 Secondary Air Injection System Control "A" Circuit

DESCRIPTION

Refer to DTC P0412 Click here.

DTC No. DTC Detection Condition Trouble Area
P0418

All conditions are met for 3 seconds or more while idling immediately after the engine is started (1 trip detection logic):


  • Secondary air injection system is not operating (the air pump and air switching valve are off).

  • Diagnostic signal from the air injection control driver has a duty cycle of 20% (this indicates an open in the air pump circuit).

  • Battery voltage is 8 V or higher.

  • Open in air pump drive circuit

  • Air pump assembly

  • Air injection control driver

  • ECM
P0418

All conditions are met for 3 seconds or more while idling immediately after the engine is started (1 trip detection logic):


  • Secondary air injection system is operating (the air pump and air switching valve are on).

  • Diagnostic signal the from air injection control driver has a duty cycle of 20% (this indicates a short in the air pump circuit).

  • Battery voltage is 8 V or higher.

  • Short between air pump drive circuit and body ground

  • Air pump assembly

  • Air injection control driver

  • ECM

MONITOR DESCRIPTION

This DTC indicates an open or short circuit in the circuit containing the air pump of the secondary air injection system. The air injection control driver performs diagnosis of the air pump, air switching valve and itself, and sends the results of this diagnosis to the ECM as a duty signal. When the ECM receives a signal indicating a malfunction in the air pump, air switching valve or air injection control driver, it illuminates the MIL and stores a DTC.

CONFIRMATION DRIVING PATTERN

Note


  • This Secondary Air Injection Check only allows technicians to operate the AIR system for a maximum of 5 seconds. Furthermore, the check can only be performed up to 4 times per trip. If the test is repeated, intervals of at least 30 seconds are required between checks. While AIR system operation using the GTS is prohibited, the GTS display indicates the prohibition (WAIT or ERROR). If ERROR is displayed on the GTS during the test, stop the engine for 10 minutes, and then try again.

  • Performing Secondary Air Injection Check repeatedly may cause damage to the secondary air injection system. If it is necessary to repeat the check, leave an interval of several minutes between System Check operations to prevent the system from overheating.

  • When performing the Secondary Air Injection Check operation after the battery cable has been reconnected, wait for 7 minutes with the engine switch turned on (IG) or the engine running.

  • Turn the engine switch off when the Secondary Air Injection Check operation finishes.


  1. Start the engine and warm it up.

  2. Turn the engine switch off.

  3. Connect the GTS to the DLC3.

  4. Turn the engine switch on (IG).

  5. Turn the GTS on.

  6. Clear DTCs (even if no DTCs are stored, perform the clear DTC operation) Click here.

  7. Turn the engine switch off and wait for at least 30 seconds.

  8. Turn the engine switch on (IG) and turn the GTS on.

  9. Enter the following menus: Powertrain / Engine and ECT / Utility / Secondary Air Injection Check / Automatic Mode.

  10. Start the engine after the GTS initialization is finished.

  11. Perform the System Check operation by pressing ENTER (Next).

  12. Perform the following to confirm the AIR system pending codes: Press ENTER (Exit).

  13. Check for pending DTCs.

    OK
    No pending DTC is output.

  14. After "Secondary air injection check" is completed, check for All Readiness by entering the following menus: Powertrain / Engine and ECT / Utility / All Readiness.

  15. Input the DTC: P0418.

  16. Check the DTC judgment result.

    GTS Display Description
    NORMAL

    • DTC judgment completed

    • System normal
    ABNORMAL

    • DTC judgment completed

    • System abnormal
    INCOMPLETE

    • DTC judgment not completed

    • Perform driving pattern after confirming DTC enabling conditions
    N/A

    • Unable to perform DTC judgment

    • Number of DTCs which do not fulfill DTC preconditions has reached ECU memory limit

    Tech Tips


    • If the judgment result shows NORMAL, the system is normal.

    • If the judgment result shows ABNORMAL, the system has a malfunction.

  17. Turn the engine switch off.

WIRING DIAGRAM

Refer to DTC P0412 Click here.

INSPECTION PROCEDURE

Tech Tips


  • By using the GTS to perform the Secondary Air Injection Check operation in the System Check, the air-fuel ratio and the pressure in the secondary air injection system passage can be checked while the secondary air injection system is operating. This helps technicians to troubleshoot the system when it malfunctions.

  • Read freeze frame data using the GTS. Freeze frame data records the engine condition when malfunctions are detected. When troubleshooting, freeze frame data can help determine if the vehicle was moving or stationary, if the engine was warmed up or not, if the air-fuel ratio was lean or rich, and other data from the time the malfunction occurred.

PROCEDURE


  1. CHECK HARNESS AND CONNECTOR (AIR PUMP - AIR INJECTION CONTROL DRIVER, BODY GROUND)


    1. Disconnect the air pump connector.

    2. Disconnect the air injection control driver connector.

    3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance
      Tester Connection Condition Specified Condition
      C57-2 (B) - C29-2 (VP) Always Below 1 Ω
      C57-4 (E) - Body ground Always Below 1 Ω
      C29-1 (BATT) - Positive (+) battery terminal Always Below 1 Ω
      C57-2 (B) or C29-2 (VP) - Body ground Always 10 kΩ or higher
      C29-1 (BATT) or Positive (+) battery terminal - Body ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  2. CHECK AIR PUMP ASSEMBLY


    1. Inspect the air pump assembly Click here.


    NG

    REPLACE AIR PUMP ASSEMBLY Click here

    OK

    REPLACE AIR INJECTION CONTROL DRIVER Click here

  3. REPLACE AIR PUMP ASSEMBLY


    1. Replace the air pump assembly Click here.


    NEXT

  4. CHECK WHETHER DTC OUTPUT RECURS (DTC P0418)


    1. Start the engine and warm it up.

    2. Turn the engine switch off.

    3. Connect the GTS to the DLC3.

    4. Turn the engine switch on (IG) and turn the GTS on.

    5. Clear DTCs (if stored) Click here.

    6. Enter the following menus: Powertrain / Engine and ECT / Utility / Secondary Air Injection Check / Automatic Mode.

    7. Start the engine after the GTS initialization is finished.

    8. Perform the System Check operation by pressing Next.

    9. After operating the secondary air injection system, perform the following to confirm the secondary air injection system pending codes: Press the Exit button.

    10. Check pending DTCs.

      OK
      No pending DTC is output.

    11. Turn the engine switch off.

      Note


      • When performing the Secondary Air Injection Check operation after the battery cable has been reconnected, wait for 7 minutes with the engine switch turned on (IG) or the engine running.

      • Turn the engine switch off when the Secondary Air Injection Check operation finishes.


    NG

    REPLACE AIR INJECTION CONTROL DRIVER Click here

    OK

    END