Toyota Tundra. Manual — part 1614

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 cold engine starts, 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.

HINT:

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

2009 Toyota Tundra

2009 ENGINE PERFORMANCE Engine Control System (3UR-FBE) - Tundra

Saturday, June 19, 2010 7:34:45 PM

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Fig. 243: Secondary Air Injection System Diagram
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.

DTC DETECTION CONDITION AND TROUBLE AREA REFERENCE CHART

DTC

DTC Detection Condition

Trouble Area

P2431
P2436

Pressure sensor indicates less than
45.6 kPa (342 mmHg), or more
than 135 kPa (1013 mmHg) (2 trip
detection logic)



Pressure sensor



Open or short in pressure
sensor circuit

2009 Toyota Tundra

2009 ENGINE PERFORMANCE Engine Control System (3UR-FBE) - Tundra

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MONITOR DESCRIPTION



ECM

P2432
P2437

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



Pressure sensor



Open or short in pressure
sensor circuit



ECM

P2433
P2438

While engine running, voltage
output of pressure sensor remains
above 4.5 V (1 trip detection
logic)



Pressure sensor



Open or short in pressure
sensor circuit



ECM

2009 Toyota Tundra

2009 ENGINE PERFORMANCE Engine Control System (3UR-FBE) - Tundra

Saturday, June 19, 2010 7:34:45 PM

Page 551

© 2006 Mitchell Repair Information Company, LLC.

Fig. 244: Pressure Sensor Circuit (Bank 1)
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.

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.

2009 Toyota Tundra

2009 ENGINE PERFORMANCE Engine Control System (3UR-FBE) - Tundra

Saturday, June 19, 2010 7:34:45 PM

Page 552

© 2006 Mitchell Repair Information Company, LLC.