Toyota Tundra. Manual — part 1395

TYPICAL ENABLING CONDITIONS

TYPICAL ENABLING CONDITIONS

TYPICAL MALFUNCTION THRESHOLDS

TYPICAL MALFUNCTION THRESHOLDS

INSPECTION PROCEDURE

HINT:



The following conditions may also cause DTC P0505 to be set:

a. The floor carpet overlapping slightly onto the accelerator pedal, causing the accelerator pedal to be

slightly depressed and therefore the throttle valve position to be slightly open.

b. The accelerator pedal being not fully released.



Read freeze frame data using the Techstream. 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.

1. CHECK ANY OTHER DTCS OUTPUT (IN ADDITION TO DTC P0505)

a. Connect the Techstream to the DLC3.

b. Turn the ignition switch to ON.

c. Turn the Techstream ON.

d. Enter the following menus: Powertrain/Engine and ECT/Trouble Codes.

e. Read DTCs.

Result

Duration

10 minutes

MIL Operation

2 driving cycles

Sequence of Operation

None

Engine

Running

Either of following conditions 1 or 2 met

-

1. Frequency that both of following conditions (a)
and (b) set

5 times or more

(a) Engine RPM - Target engine RPM

Less than -100 RPM, or more than 150 RPM

(b) Vehicle condition

Stop after vehicle was driven at 10 km/h (6.25 mph)
or more

2. Frequency that both of following conditions (c)
and (d) set

Once

(c) Engine RPM - Target engine RPM

Less than -100 RPM, or more than 150 RPM

(d) IAC flow rate learning value

2.48 L/sec. or less, or 11.0 L/sec. or more

2008 Toyota Tundra

2008 ENGINE PERFORMANCE Engine Control System (2UZ-FE) - Tundra

RESULT REFERENCE

HINT:

If any DTCs other than P0505 are output, troubleshoot those DTCs first.

B : GO TO DTC CHART (See DIAGNOSTIC TROUBLE CODE CHART )

A : Go To Next Step

2. CHECK PCV HOSE CONNECTIONS

OK: PCV hose is connected correctly and is not damaged.

NG : REPAIR OR REPLACE PCV HOSE

OK : Go To Next Step

3. CHECK AIR INDUCTION SYSTEM

a. Check the air induction system for vacuum leakage. (See ON-VEHICLE INSPECTION ).

OK: No leakage from air induction system.

NG : REPAIR OR REPLACE AIR INDUCTION SYSTEM

OK : Go To Next Step

4. CHECK THROTTLE VALVE

a. Check the throttle valve condition.

OK: Throttle valve is not contaminated with foreign objects and moves smoothly.

NG : REPLACE THROTTLE BODY ASSEMBLY (See REMOVAL )

OK : REPLACE ECM (See REMOVAL )

DTC P050A COLD START IDLE AIR CONTROL SYSTEM PERFORMANCE

DESCRIPTION

DTC DETECTION CONDITION AND TROUBLE AREA

Result

Proceed To

P0505 is output

A

P0505 and other DTCs are output

B

DTC Code

DTC Detection Condition

Trouble Area

2008 Toyota Tundra

2008 ENGINE PERFORMANCE Engine Control System (2UZ-FE) - Tundra

This monitor will run when the engine is started with the engine coolant temperature at -10 to 50°C (14 to 122°
F). The DTC will be set after the engine idles for 13 seconds (2 trip detection logic).

The DTC is designed to monitor the idle air control at cold start. When the engine is started with the engine
coolant temperature at lower than 50°C (122°F), the ECM (PCM) measures the accumulated mass airflow at
engine idling. If it does not reach the criteria within 10 seconds, the ECM (PCM) interprets this as a
malfunction. The MIL is illuminated and a DTC is set when the malfunction is detected in consecutive driving
cycles (2 trip detection logic).

The ETCS (Electronic Throttle Control System) controls the idle speed. The ETCS operates the throttle actuator
to open and close the throttle valve, and adjusts the intake air amount to achieve the target idle speed.

Fig. 182: Engine Coolant Temperature Graph

P050A

Insufficient mass air flow at cold start (2 trip detection logic)



Throttle body



Mass air flow meter



PCV hose



Air cleaner filter



Air induction system



VVT system



ECM

NOTE:

When the negative battery terminal is disconnected during inspections or
repairs, the ISC (Idle Speed Control) learning values are cleared. This DTC
cannot be set with the ISC learning values cleared.
The ISC learning is performed when the engine is warmed up and has been
idling for 5 minutes.

2008 Toyota Tundra

2008 ENGINE PERFORMANCE Engine Control System (2UZ-FE) - Tundra

MONITOR STRATEGY

MONITOR STRATEGY

MONITOR STRATEGY

TYPICAL ENABLING CONDITIONS

TYPICAL ENABLING CONDITIONS

TYPICAL MALFUNCTION THRESHOLDS

TYPICAL MALFUNCTION THRESHOLDS

INSPECTION PROCEDURE

1. CHECK DTCS

OK: Any other DTCs are not set.

NG : GO TO DIAGNOSTIC TROUBLE CODE CHART

OK : Go To Next Step

2. READ VALUE USING TECHSTREAM (FUEL TRIM)

HINT:

Related DTCs

P050A: Cold start idle air speed control system

Required sensors/Components (Main)

Throttle body

Required sensors/Components (Related)

Mass air flow meter
Engine coolant temperature sensor

Frequency of operation

Once per driving cycle

Duration

10 seconds

MIL operation

2 driving cycles

Sequence of operation

None

Battery voltage

8 V or higher

Time after engine start

3 seconds or more

Starter

OFF

ECT at engine start

-10°C (14°F) or more

ECT

-10 to 50°C (14 to 122°F)

Engine idling

3 seconds or more

Fuel-cut

OFF

Vehicle speed

Less than 1.875 mph (3 km/h)

Atmospheric pressure

76 kPa (570 mmHg) or more

Accumulated mass air flow

Less than 52.4 g (varies with ECT)

2008 Toyota Tundra

2008 ENGINE PERFORMANCE Engine Control System (2UZ-FE) - Tundra