P1444
DTC P1444 SECONDARY AIR INJECTION SYSTEM SWITCHING VALVE NO.2 BANK 2 STUCK OPENCIRCUIT DESCRIPTION
DTC Detection Condition:
The secondary air injection system pumps air to the exhaust port to accelerate the activation of the catalyst.
The secondary air injection system consists of the ECM, air pump, Air Switching Valve (ASV) (EASV), Air Switching Valve No.2 (ASV No.2) (ASV1, 2), pressure sensor and air injection driver (AID). The Air Switching Valve (ASV) (EASV) is an electromagnetic type and Air Switching Valve No.2 (ASV No.2) (ASV1,2) is a vacuum type.
The secondary air injection system pumps pressurized air to the exhaust port by the air pump through the ASV and ASV No.2. The ASV assists the ASV No.2. The ASV No.2 also controls air supply.
The ECM sends signals to the AID, and then the AID operates the air pump and ASV. The pressure sensor detects pressure and exhaust pulsation in the system when the system operates and when it does not operate, and sends the data to the ECM.
MONITOR DESCRIPTION
Monitor Strategy:
Typical Enabling Condition Part 1:
Typical Enabling Condition Part 2:
Typical Malfunction Thresholds:
The ECM detects pressure change with the pressure sensor to determine malfunctioning parts in the system, and stores the DTCs. The ECM measures pressure and/or exhaust pulsation of the system at 6 points, A to F, when the air injection system is in operation or when not in operation. When the pressure is high, the ECM determines that the pump operates. When exhaust pulsation is detected, the ECM determines that the ASV is open. The ECM determines malfunction parts based on the measured value, and stores the DTCs.
Points A and B:
ECM detects pressure changes (decrease), and determines that the ASV No.2 is open.
Points C and F:
ECM detects pressure and exhaust pulsation, and determines the pressure pattern of the system.
Point D:
ECM operates the system, as indicated by the dashed lines, to determine which of the ASV No.2 is malfunctioning only when pressure changes cannot be detected at point A or B.
Point E:
ECM detects exhaust pulsation to determine the condition of the system.
Pressure condition in Secondary Air Injection System (Point C and F)
MONITOR RESULT
Refer to "Monitors, Trips and/or Drive cycle" for detailed information.
The test value and test limit information are described as shown in the table. Check the monitor result and test values after performing the monitor drive pattern (refer to "Confirmation Monitor").
- MID (Monitor Identification Data) is assigned to each emissions-related component.
- TID (Test Identification Data) is assigned to each test value.
- Scaling is used to calculate the test value indicated on generic OBD II scan tools.
Wiring Diagram:
Step 1 - 2:
Step 3 - 4:
Step 5 - 6:
Step 7:
Step 8:
Step 9:
Step 10:
Step 11:
INSPECTION PROCEDURE
CHECK FOR INTERMITTENT PROBLEMS
HINT:
Hand-held tester only:
Inspect the vehicle's ECM using check mode. Intermittent problems are easier to detect when the ECM is in check mode with a hand-held tester. In check mode, the ECM uses 1 trip detection logic, which has a higher sensitivity to malfunctions than normal mode (default) using 2 trip detection logic.
a. Clear the DTCs.
b. Switch the hand-held tester from normal mode to check mode.
c. Perform a simulation test.
d. Check the connector(s) and terminal(s).
e. Wiggle the harness(s) and connector(s).