Toyota Tundra. Manual — part 1358

Fig. 95: Fuel Compensation Amount

MONITOR STRATEGY

MONITOR STRATEGY

TYPICAL ENABLING CONDITIONS

TYPICAL ENABLING CONDITIONS

Related DTCs

P0171: Fuel trim lean (bank 1)
P0172: Fuel trim rich (bank 1)
P0174: Fuel trim lean (bank 2)
P0175: Fuel trim rich (bank 2)

Required Sensors/Components (Main)

Fuel system

Required Sensors/Components (Related)

A/F sensor, Mass air flow meter, Crankshaft position sensor

Frequency of Operation

Continuous

Duration

Within 10 seconds

MIL Operation

2 driving cycles

Sequence of Operation

None

Monitor runs whenever following DTCs not

P0010, P0020 (VVT OCV)
P0011 (VVT System 1 - Advance)
P0012 (VVT System 1 - Retard)
P0021 (VVT System 2 - Advance)
P0022 (VVT System 2 - Retard)
P0031, P0032, P0051, P0052 (A/F Sensor Heater -
Sensor 1)
P0102 - P0103 (MAF meter)
P0115 - P0118 (ECT sensor)

2008 Toyota Tundra

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

TYPICAL MALFUNCTION THRESHOLDS

TYPICAL MALFUNCTION THRESHOLDS

WIRING DIAGRAM

Refer to DTC P2195 .

INSPECTION PROCEDURE

HINT:



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.



A low A/F sensor voltage could be caused by a rich air-fuel mixture. Check for conditions that would
cause the engine to run rich.



A high A/F sensor voltage could be caused by a lean air-fuel mixture. Check for conditions that would
cause the engine to run lean.

1. CHECK ANY OTHER DTCS OUTPUT (IN ADDITION TO DTC P0171, P0172, P0174 OR P0175)

a. Connect the Techstream to the DLC3.

b. Turn the ignition switch to ON and turn the Techstream ON.

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

present

P0120 - P0223, P2135 (TP sensor)
P0125 (Insufficient ECT for Closed Loop)
P0335 (CKP sensor)
P0351 - P0354 (Igniter)
P0500 (VSS)
P2440 (AIR control valve stuck open)
P2441 (AIR control valve stuck close)
P2444 (AIP stuck On)
P2445 (AIP stuck Off)

Fuel system status

Closed loop

Battery voltage

11V or higher

Either of following conditions 1 or 2 set

-

1. Engine RPM

Below 1000 RPM

2. Intake air amount per revolution

0.26 g/rev or more

Catalyst monitor

Not executed

Purge-cut

Executing

Either of following conditions 1 or 2 met

-

1. Average of short-term fuel trim and long-term fuel trim

35% or more (varies with ECT)

2. Average of short-term fuel trim and long-term fuel trim

-35% or less (varies with ECT)

2008 Toyota Tundra

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

d. Read DTCs.

Result

RESULT REFERENCE

HINT:

If any DTCs other than P0171, P0172, P0174 or P0175 are output, troubleshoot those DTCs first.

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

A : Go To Next Step

2. PERFORM ACTIVE TEST USING TECHSTREAM (A/F CONTROL)

a. Connect the Techstream to the DLC3.

b. Start the engine and turn the Techstream ON.

c. Warm up the engine at an engine speed of 2500 RPM for approximately 90 seconds.

d. Enter the following menus: Powertrain/Engine and ECT/Active Test/Control the Injection Volume

for A/F Sensor.

e. Perform the Control the Injection Volume for A/F Sensor operation with the engine in an idling

condition (press the RIGHT or LEFT button to change the fuel injection volume).

f. Monitor the output voltages of A/F and HO2 sensors (AFS B1S1 and O2S B1S2 or AFS B2S1 and

O2S B2S2) displayed on the Techstream.

Result:

The A/F sensor reacts in accordance with increases and decreases in the fuel injection
volume:

+25% = Rich output:

Less than 3.0 V

-12.5% = Lean output:

More than 3.35 V

Result

Proceed To

P0171, P0172, P0174 or P0175 is output

A

P0171, P0172, P0174 or P0175 and other DTCs are output

B

NOTE:

The A/F sensor has an output delay of a few seconds and the HO2
sensor has a maximum output delay of approximately 20 seconds.

2008 Toyota Tundra

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

A/F SENSOR (SENSOR 1) OUTPUT VOLTAGE REFERENCE

Following the Control the Injection Volume for A/F Sensor procedure enables technicians to check
and graph the voltage outputs of both the A/F and HO2 sensors.

Enter the following menus: Powertrain/Engine and ECT/Active Test/Control the Injection Volume
for A/F Sensor/A/F Control System/AFS B1 S1 and O2S B1 S2 or AFS B2 S1 and O2S B2 S2.

Result

RESULT REFERENCE

B : Go to step 11

C : Go to step 15

A : Go To Next Step

3. READ VALUE USING TECHSTREAM (MAF)

a. Check the mass air flow meter. (See REMOVAL ).

NG : REPLACE MASS AIR FLOW METER (See REMOVAL )

OK : Go To Next Step

Case

A/F Sensor (Sensor 1)

Output Voltage

HO2 Sensor (Sensor 2)

Output Voltage

Main Suspected Trouble

Area

1

-

2



A/F sensor



A/F sensor heater



A/F sensor circuit

3



Injector



Fuel pressure



Gas leakage from
exhaust system (Air-
fuel ratio extremely
rich or lean)

Result Proceed To
Case 1

C

Case 2

B

Case 3

A

2008 Toyota Tundra

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