Toyota Tundra. Manual — part 1252

OK : CHECK FOR INTERMITTENT PROBLEMS . (See CHECK FOR INTERMITTENT
PROBLEMS).

DTC P2444 SECONDARY AIR INJECTION SYSTEM PUMP STUCK ON BANK 1; DTC P2445
SECONDARY AIR INJECTION SYSTEM PUMP STUCK OFF BANK 1; DTC P2446 SECONDARY
AIR INJECTION SYSTEM PUMP STUCK ON BANK 2; DTC P2447 SECONDARY AIR INJECTION
SYSTEM PUMP STUCK OFF BANK 2

DESCRIPTION

Refer to P2440 .

DTC TROUBLE DETECTION CONDITION CHART

MONITOR DESCRIPTION

The ECM monitors the pressure in the Secondary air passage using the pressure sensor located on the Air
Switching Valve (ASV) of the Secondary Air Injection (AIR) system. The sensor measures the pressure in the
secondary air passage and transmits a signal to the ECM.

If either of the following conditions occurs, the ECM interprets it as a malfunction of the AIR system, and
illuminates the MIL and sets a DTC:



The pressure indicated by the pressure sensor does not reach threshold levels despite the ECM turning on

DTC

No.

DTC Detection Condition

Trouble Area

P2444
P2446

Secondary air pressure more than 1 kPa (37.5 mmHg) despite
ECM commanding air pump to turn off (2 trip detection
logic)



Short in air pump circuit



Open or short in pressure
sensor circuit



Pressure sensor



Air Injection Control Driver
(AID)



ECM

P2445
P2447

Secondary air pressure less than 1 kPa (7.5 mmHg) despite
ECM commanding air pump to turn on (2 trip detection logic)



Air pump



Open in air pump circuit



Air injection system piping



Vacuum hose (pressure
sensor - air switching valve)



Pressure sensor



Open or short in pressure
sensor circuit



Air Injection Control Driver
(AID)



ECM

2008 Toyota Tundra

2008 ENGINE PERFORMANCE Engine Control System (1GR-FE) - Tundra

the air pump.



The pressure indicated by the pressure sensor exceeds threshold levels despite the ECM turning off the air
pump.

MONITOR STRATEGY

MONITOR STRATEGY

TYPICAL ENABLING CONDITIONS

All:

TYPICAL ENABLING CONDITIONS

Case 1:

TYPICAL ENABLING CONDITIONS

Related DTCs

P2444: Air pump stuck ON
P2445: Air pump stuck OFF
P2446: Air pump stuck ON
P2447: Air pump stuck OFF

Required Sensors/Components (Main)

Pressure sensor

Required Sensors/Components (Related)

-

Frequency of Operation

Once per drive cycle

Duration

7 seconds

MIL Operation

2 driving cycles

Sequence of Operation

None

Monitor runs whenever following DTCs not present

P0010 - P0022: VVT system
P0031 - P0052: Front A/F sensor heater
P0102 - P0103: MAF sensor
P0110 - P0113: IAT sensor
P0115 - P0118: ECT sensor
P0120 - P2125: TP sensor
P0125: Closed loop
P0171 - P0175: Fuel trim
P0300 - P0306: Misfire
P0325 - P0333: Knock sensor
P0335: CKP sensor
P0340 - P0346: VVT sensor
P0351 - P0356: Igniter
P0441 - P2420: EVAP system
P0500: VSS
P2195 - P2A03: A/F sensor
P2430 - P2433: AIR pressure sensor

Battery voltage

11 V or more

Atmospheric pressure

45 kPa (337.5 mmHg) or more

2008 Toyota Tundra

2008 ENGINE PERFORMANCE Engine Control System (1GR-FE) - Tundra

Case 2:

TYPICAL ENABLING CONDITIONS

Case 3:

TYPICAL ENABLING CONDITIONS

TYPICAL MALFUNCTION THRESHOLDS

Condition 1:

TYPICAL MALFUNCTION THRESHOLDS

Condition 2:

TYPICAL MALFUNCTION THRESHOLDS

Condition 3:

TYPICAL MALFUNCTION THRESHOLDS

Secondary air injection pump

ON

Secondary air injection switching valve

ON

Engine speed

Less than 3750 RPM

Delay time after engine started

5 seconds or more

Pressure sensor malfunction

Not detected

Secondary air injection pump

OFF

Engine speed

Less than 3750 RPM

Secondary air injection system monitor during secondary air injection ON

Completed

Pressure sensor malfunction

Not detected

Coolant temperature at engine start

Less than 5°C (41°F)

Ambient temperature at engine start

-15°C (5°F) or more

Cumulative intake air amount

150g/sec. or more

Throttle angle

20° or more

AIR valve

OFF

Pressure sensor malfunction

Not detected

Injection driver malfunction

Not detected

Duration of the following condition

10 to 60 minutes

Engine coolant temperature

25°C (77°F) or more

AIR pressure during AIR ON

1 kPa or more and pulse is generated

AIR pressure during AIR ON

Less than 1 kPa and pulse is generated

AIR pressure during AIR ON

1 kPa or more and pulse is not generated

2008 Toyota Tundra

2008 ENGINE PERFORMANCE Engine Control System (1GR-FE) - Tundra

Condition 4:

TYPICAL MALFUNCTION THRESHOLDS

Condition 5:

TYPICAL MALFUNCTION THRESHOLDS

Condition 6:

TYPICAL MALFUNCTION THRESHOLDS

Condition 7:

TYPICAL MALFUNCTION THRESHOLDS

Condition 8:

TYPICAL MALFUNCTION THRESHOLDS

Case 1:

TYPICAL MALFUNCTION THRESHOLDS

Case 2:

TYPICAL MALFUNCTION THRESHOLDS

Case 3:

TYPICAL MALFUNCTION THRESHOLDS

AIR pressure during AIR ON

Less than 1 kPa and pulse is not generated

AIR pressure during AIR OFF

1 kPa or more and pulse is generated

AIR pressure during AIR OFF

Less than 1 kPa and pulse is generated

AIR pressure during AIR OFF

1 kPa or more and pulse is not generated

AIR pressure during AIR OFF

Less than 1 kPa and pulse is not generated

Both of following conditions met:

(a) and (b)

(a) Not condition 6

Met

(b) Not condition 8

Met

Both of following conditions met:

(a) and (b)

(a) Not condition 1

Met

(b) Not condition 3

Met

AIR amount

4 L/min or less

2008 Toyota Tundra

2008 ENGINE PERFORMANCE Engine Control System (1GR-FE) - Tundra