SFI SYSTEM, Diagnostic DTC:P2431, P2432, P2433, P2436, P2437, P2438

DTC Code DTC Name
P2431 Secondary Air Injection System Air Flow / Pressure Sensor Circuit Range / Performance Bank1
P2432 Secondary Air Injection System Air Flow / Pressure Sensor Circuit Low Bank1
P2433 Secondary Air Injection System Air Flow / Pressure Sensor Circuit High Bank1
P2436 Secondary Air Injection System Air Flow / Pressure Sensor Circuit Range / Performance Bank 2
P2437 Secondary Air Injection System Air Flow / Pressure Sensor Circuit Low Bank 2
P2438 Secondary Air Injection System Air Flow / Pressure Sensor Circuit High Bank 2

DESCRIPTION

The Secondary Air injection (AIR) system consists of an air pump, the Air Switching Valve (ASV), a pressure sensor, the Air Injection Control Driver (AID) and the ECM. For a short time after a cold engine start, the AIR system pumps secondary air to the exhaust port of the cylinder head to purify the exhaust emissions. The secondary air is supplied by the air pump and is pumped to the exhaust port through the ASV.

The AID drives the ASV and the air pump according to command signals transmitted by the ECM. The pressure sensor detects the pressure in the secondary air passage when the AIR system is ON and OFF, and transmits a pressure signal to the ECM.

The AID is not only equipped to drive the pump and valve, but also with a diagnosis function to detect malfunctions in the AIR system circuit.

Tech Tips

As a large current is required to drive the air pump and ASV, an AID is installed to this system.

B00197VE06
DTC Code DTC Detection Condition Trouble Area

P2431

P2436

 The pressure sensor indicates below 45.6 kPa (342 mmHg), or higher than 135 kPa (1013 mmHg) (2 trip detection logic).

  • Pressure sensor

  • Open or short in pressure sensor circuit

  • ECM

P2432

P2437

 While the engine is running, the voltage output of the pressure sensor remains below 0.5 V (1 trip detection logic).

  • Pressure sensor

  • Open or short in pressure sensor circuit

  • ECM

P2433

P2438

 While the engine is running, the voltage output of the pressure sensor remains higher than 4.5 V (1 trip detection logic).

  • Pressure sensor

  • Open or short in pressure sensor circuit

  • ECM

MONITOR DESCRIPTION

A01WU2JE41
Reference (for Bank 1)
*1 VCAI
*2 EAIP
*3 Pressure Sensor

The ECM monitors the pressure in the secondary air passage using the pressure sensor located on the air switching valve in the secondary air injection system.

If there is a defect in the sensor or the sensor circuit, the voltage level deviates from the normal operating range, the ECM interprets this deviation as a malfunction in the pressure sensor or circuit and stores DTC(s).

WIRING DIAGRAM

Refer to DTC P0412 Click here.

CAUTION / NOTICE / HINT

Tech Tips

Read freeze frame data using the intelligent tester. 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 (PRESSURE SENSOR - ECM)


    1. Disconnect the pressure sensor connector.

    2. Disconnect the ECM connectors.

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

      Standard Resistance
      for LHD
      Tester Connection Condition Specified Condition
      C35-3 (AIP) - C53-73 (AIP) Always Below 1 Ω
      C35-2 (VC) - C53-75 (VCAI) Always Below 1 Ω
      C35-4 (E2) - C53-74 (EAIP) Always Below 1 Ω
      C36-3 (AIP2) - C53-72 (AIP2) Always Below 1 Ω
      C36-2 (VC2) - C53-75 (VCAI) Always Below 1 Ω
      C36-4 (E22) - C53-74 (EAIP) Always Below 1 Ω
      C35-3 (AIP) or C53-73 (AIP) - Body ground Always 10 kΩ or higher
      C35-2 (VC) or C53-75 (VCAI) - Body ground Always 10 kΩ or higher
      C36-3 (AIP2) or C53-72 (AIP2) - Body ground Always 10 kΩ or higher
      C36-2 (VC2) or C53-75 (VCAI) - Body ground Always 10 kΩ or higher
      for RHD
      Tester Connection Condition Specified Condition
      C35-3 (AIP) - C54-73 (AIP) Always Below 1 Ω
      C35-2 (VC) - C54-75 (VCAI) Always Below 1 Ω
      C35-4 (E2) - C54-74 (EAIP) Always Below 1 Ω
      C36-3 (AIP2) - C54-72 (AIP2) Always Below 1 Ω
      C36-2 (VC2) - C54-75 (VCAI) Always Below 1 Ω
      C36-4 (E22) - C54-74 (EAIP) Always Below 1 Ω
      C35-3 (AIP) or C54-73 (AIP) - Body ground Always 10 kΩ or higher
      C35-2 (VC) or C54-75 (VCAI) - Body ground Always 10 kΩ or higher
      C36-3 (AIP2) or C54-72 (AIP2) - Body ground Always 10 kΩ or higher
      C36-2 (VC2) or C54-75 (VCAI) - Body ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  2. INSPECT AIR SWITCHING VALVE (PRESSURE SENSOR)

    A01WPEWE11
    *1 for Bank 1:
    *2 Pressure Gauge
    *3 for Bank 2:

    1. Connect a pressure gauge to the air pressure sensor as shown in the illustration.

    2. Connect the intelligent tester to the DLC3.

    3. Turn the engine switch on (IG) and turn the tester on.

    4. Enter the following menus: Powertrain / Engine and ECT / Data List / Air pump pressure (Absolute) and Air Pump2 Pressure (Absolute).

    5. Check that the pressure displayed on the tester fluctuates when applying the pressure to the pressure sensor with the pressure gauge.

      OK
      Pressure fluctuates in response to pressure applied with pressure gauge.

      Tech Tips

      The tester displays the air pump pressure as absolute pressure.


    OK

    REPLACE ECM Click here

    NG

    REPLACE AIR SWITCHING VALVE Click here