Caution / Notice / Hint

HINT: 

Determination by ECM monitoring:

The ECM locates malfunctions in the Secondary Air Injection (AIR) system by detecting the pressure in the AIR passage between the air pump and Air Switching Valve (ASV) and stores a DTC. Soon after cold engine starts, the monitor runs for a short time while the AIR system is both ON and OFF. The ECM detects both the pressure and the exhaust pulsation and compares them.

The following 8 patterns are AIR system pressure conditions in the AIR system passage.

If the detected pressure is high, the air pump is assumed to be ON and if it alternates sharply, the ASV is assumed to be open. The ECM locates malfunctions from the combination of pressures detected when the AIR system is ON and OFF.

HINT: 

The exhaust pulsation value is calculated in the ECM. If the calculated value exceeds a certain level, the ECM determines that the exhaust pulsation is in the AIR system.

HINT: 

• In case 3 and 7, as the pressure sensor detects a slight pump operation pulsation, the detected value is not constant. Since the pump outlet is blocked by closing the ASV, the average pressure is higher than in case 1 (approximately 10 to 30 kPa).
• In case 1, the average pressure is approximately 3 to 11 kPa. The value of 2.4 kPa indicated in the table above is a threshold for detecting pump malfunctions.

HINT: 

• If the vacuum hose between the ASV and the pressure sensor is not connected correctly, case 4 may occur.
• By using the Techstream 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. Furthermore, Pending Codes also can be checked by performing Utility / Secondary Air Injection Check / Automatic Mode after the repair.
• Read freeze frame data using the Techstream. 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.
• Bank 1 refers to the bank that includes the No. 1 cylinder*.

  *: The No. 1 cylinder is the cylinder which is farthest from the transmission.

• Bank 2 refers to the bank that does not include the No. 1 cylinder.

1. System Check:
2. The pressure in the secondary air passage can be checked using the Techstream.
   1. Start the engine and warm it up.
   2. Turn the ignition switch off.
   3. Connect the Techstream to the DLC3.
   4. Turn the ignition switch to ON and turn the Techstream on.
   5. Enter the following menus: Powertrain / Engine and ECT / Utility / Secondary Air Injection Check / Manual Mode / AIR PUMP 1: ON, ASV1: OPEN, AIR PUMP 2: ON, ASV2: OPEN and AIR PUMP 1: OFF, ASV1 CLOSE, AIR PUMP 2: OFF, ASV2 CLOSE.

      HINT: 

      When Manual Mode is selected, the Techstream initialization (atmospheric pressure measurement) is performed automatically. The initialization takes 10 seconds. After the initialization, AIR PUMP and ASV operation can be selected.

   6. Start the engine.
   7. Perform the AIR system intrusive operation while the engine is idling.
   8. Check that the air pump (AIR PUMP), ASV and pressure in the AIR system passage (PRESSURE) displayed on the Techstream indicate the conditions shown in the table below.

      Standard

      Operation	AIR PUMP	ASV	PRESSURE*1	PULSATION*2
      AIR PUMP: ON, ASV: OPEN	ON	OPEN	2.4 kPa or more	10 kPa or more
      AIR PUMP: OFF, ASV: CLOSE	OFF	CLOSE	Less than 2.4 kPa	Less than 30 kPa

      *1:

      Average pumping pressure (gauge pressure). The pressure should be 2.4 kPa or more when the AIR system operates.

      *2:

      The cumulative exhaust pulsation calculated by the ECM. If the calculated value exceeds a certain level, the ECM determines that the exhaust pulsation is in the AIR system.

   9. Turn the ignition switch to OFF.
      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 Techstream is prohibited, the Techstream display indicates the prohibition (WAIT or ERROR).

        If an ERROR is displayed on the Techstream during the test, stop the engine for 10 minutes, and then try again.

      • Performing the Secondary Air Injection Check repeatedly may cause damage to the AIR system. If necessary, 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 ignition switch turned to ON or the engine running.
      • Turn the ignition switch off when the Secondary Air Injection Check operation finishes.