Repairing A 2102 Toyota Tacoma Sec Switching Valve

Refer to DTC P2440 (See page ES-356).

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 sets 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 4 patterns are AIR system pressure conditions in the AIR system passage. Pressure condition in Secondary Air Injection System Case 1:

Air Pump

ON

Air Switching Valve

Open

Pressure

2.5 kPa or more

Pulsation Detection

Exhaust gas pulsation detected

Pressure condition in Secondary Air Injection System Case 2:

Air Pump

OFF

Air Switching Valve

Open

Pressure

Less than 2.5 kPa

Pulsation Detection

Exhaust gas pulsation detected

Pressure condition in Secondary Air Injection System Case 3:

Air Pump

ON

Air Switching Valve

Closed

Pressure

2.5 kPa or more

Pulsation Detection

Slight pulsation detected

Pressure condition in Secondary Air Injection System Case 4:

Air Pump

OFF

Air Switching Valve

Closed

Pressure

Less than 2.5 kPa

Pulsation Detection

Exhaust pulsation not detected

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.

: 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, 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 20 to 30 kPa).

• In case 1, the average pressure is approximately 9 to 11 kPa. The value of 2.5 kPa indicated in the table above is a threshold for detecting pump malfunctions.

Detected Conditions while AIR operating: Air pump ON, ASV Open

Detected Conditions while AIR not operating: Air pump OFF, ASV Closed

ECM Determination

DTCs Output

Case 1

Case 4

Normal

-

Case 1

Case 2

ASV stuck open

P2440

Case 1

Case 3

Air pump stuck ON

P2444

Case 2

Case 4

Air pump stuck OFF

P2445

Case 3

Case 4

ASV stuck closed

P2441

Case 1

Case 1

ASV stuck open and Air pump stuck ON

P2440 and P2444

Case 2

Case 2

ASV stuck open and Air pump stuck OFF

P2440 and P2445

Case 3

Case 3

ASV stuck closed and Air pump stuck ON

P2441 and P2444

Case 4

Case 4

ASV stuck closed and Air pump stuck OFF

P2441 and P2445

HINT:

• If the vacuum hose between the ASV and the pressure sensor is not connected correctly, case 4 may occur.

• By using an intelligent tester to perform the AIR INJ 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 SYSTEM CHECK / AUTOMATIC OPERATION after the repair.

• Read freeze frame data using an intelligent tester. Freeze frame data record 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.

SYSTEM CHECK:

The pressure in the secondary air passage can be checked using an intelligent tester.

(a)Start the engine and warm it up.

Intelligent Tester Display:

AIR INJ CHECK

MANUAL OPERATION

AIR PUMP

ON

ASV

OPEN

A/F BANK1

19.095

PRESSURE

17 kPa-g

PULSATION

25.39 kPa-g

AI STATUS

OK

Remaining Time 05 sec.

Press IEXITI to

(b)Turn the ignition switch to OFF.

(c) Connect an intelligent tester to the DLC3.

(d)Turn the ignition switch to ON and turn the tester ON.

(e)Select the following menu items:

DIAGNOSIS / ENHANCED OBD II / SYSTEM CHECK / AIR INJ CHECK / MANUAL OPERATION /

HINT:

When MANUAL OPERATION is selected, the tester initialization (atmospheric pressure measurement) is performed automatically. The initialization takes 10 seconds. After the initialization, AP and ASV operation canbe selected.

(f) Start the engine.

(g)Perform the AIR system intrusive operation while the engine is idling.

(h)Check that the air pump (AIR PUMP), ASV and pressure in the AIR system passage (PRESSURE) displayed on the tester, indicate the conditions shown in the table below.

Standard

Intelligent Tester Operations

AIR PUMP

ASV

PRESSURE *1

PULSATION *2

AP: ON, ASV: OPEN

ON

OPEN

2.5 kPa or more

11.25 kPa or more

AP: OFF, ASV: CLOSE

OFF

CLOSE

Less than 2.5 kPa

Less than 11.25 kPa

Average pumping pressure (gauge pressure). The pressure should be 2.5 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.

(i) Turn the ignition switch to OFF.

NOTICE:

• This 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 intelligent tester is prohibited, the tester display indicates the prohibition (WAIT or ERROR).

If an ERROR as shown in the illustration is displayed on the tester during the test, stop the engine for 10 minutes, and then try again.

• Performing the AIR INJ CHECK repetitively 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 AIR INJ 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 to OFF when the AIR INJ CHECK operation finishes.

CHECK ANY OTHER DTCS OUTPUT (IN ADDITION TO DTC P2444 AND/OR P2445)

(a) Connect an intelligent tester to the DLC3.

(b) Turn the ignition switch to ON and turn the tester ON.

(c) Select the following menu items: DIAGNOSIS / ENHANCED OBD II / DTC INFO / CURRENT CODES.

Result

Display (DTC Output)

Proceed To

P2444 and/or P2445

A

P2444 and/or P2445, and P0418

B

P2444 and/or P2445, and other DTCs (except P0418)

C

If any DTCs other than P2444, P2445 and/or P0418 are output, troubleshoot those DTCs first.

GO TO AIR PUMP INSPECTION PROCEDURE

GO TO DTC CHART

Do It Yourself Car Diagnosis

Do It Yourself Car Diagnosis

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Responses

  • KAROLIN
    What causes the tacoma secondary air valve to be stuck open?
    2 years ago
  • lleyton
    What is a p2440 code on 2012 Toyota Tacoma?
    2 years ago
  • mike
    Where is secondary air valve located on 2012 toyota tacoma?
    2 years ago
  • tim grubb
    What are the air pump valves on a toyota?
    1 year ago
  • milla
    WHAT ARE AIR PUMPS AND SWITCHING VALVES ON TACOMA?
    11 months ago
  • fethawi
    How to clean secondary air injection valve on 2012 toyota tacoma?
    6 months ago
  • sarah
    How long does reset last for secondary air tacoma?
    4 days ago

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