Toyota Tundra. Manual — part 1356

B : REPAIR COMPLETE

A : Go To Next Step

12. PERFORM ACTIVE TEST USING TECHSTREAM (INJECTION VOLUME)

Fig. 90: HO2 Sensor Voltage Output Graph

a. Connect the Techstream to the DLC3.

b. Start the engine and turn the Techstream ON.

c. Warm up the engine.

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

e. Change the fuel injection volume using the tester, and monitor the voltage output of Air-Fuel Ratio

(A/F) and HO2 sensors displayed on the tester.

HINT:



Change the fuel injection volume within the range of -12% and +12%. The injection volume
can be changed in 1% graduations within the range.



The A/F sensor is displayed as AFS B1 S1 or AFS B2 S1, and the HO2 sensor is displayed as
O2S B1 S2 or O2S B2 S2 on the Techstream.

Result

No DTC is output

B

2008 Toyota Tundra

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

RESULT REFERENCE

HINT:

A normal HO2 sensor voltage (O2S B1 S2 or O2S B2 S2) reacts in accordance with increases and
decreases in fuel injection volumes. When the A/F sensor voltage remains at either less or more
than 3.3 V despite the HO2 sensor indicating a normal reaction, the A/F sensor is malfunctioning.

NG : REPLACE AIR FUEL RATIO SENSOR (See REMOVAL )

OK : CHECK EXTREMELY RICH OR LEAN ACTUAL AIR-FUEL RATIO AND REPAIR
CASE (INJECTOR, FUEL PRESSURE, EXHAUST GAS LEAKAGE, ETC)

13. CHECK FOR EXHAUST GAS LEAK

OK: No gas leakage.

NG : REPAIR OR REPLACE EXHAUST GAS LEAKAGE POINT

OK : Go To Next Step

14. INSPECT HEATED OXYGEN SENSOR (HEATER RESISTANCE) (See INSPECTION

PROCEDURE )

NG : REPLACE HEATED OXYGEN SENSOR (See REMOVAL )

OK : Go To Next Step

15. INSPECT INTEGRATION RELAY (EFI RELAY) (See INSPECTION PROCEDURE )

NG : REPLACE INTEGRATION RELAY (See EFI RELAY )

OK : Go To Next Step

16. CHECK HARNESS AND CONNECTOR (HEATED OXYGEN SENSOR - ECM)

a. Disconnect the D31 or D32 HO2 sensor connector.

b. Turn the ignition switch to ON.

c. Measure the voltage according to the value (s) in the table below.

Standard voltage

STANDARD VOLTAGE SPECIFICATION

Tester Display (Sensor)

Voltage Variation

Proceed To

AFS B1 S1 (A/F)
AFS B2 S1 (A/F)

Alternates between more and less than 3.3 V

OK

Remains at more than 3.3 V

NG

Remains at less than 3.3 V

NG

2008 Toyota Tundra

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

d. Turn the ignition switch off.

e. Disconnect the D74 ECM connector.

f. Measure the resistance according to the value (s) in the table below.

Fig. 91: Identifying Heated Oxygen Sensor & ECM Connector Terminal

Standard resistance

STANDARD RESISTANCE SPECIFICATION

Tester Connection

Switch Condition Specified Condition

D31-2 (+B) - Body ground Ignition switch ON

9 to 14 V

D32-2 (+B) - Body ground Ignition switch ON

9 to 14 V

Tester Connection

Condition Specified Condition

D31-1 (HT1B) - D74-45 (HT1B)

Always

Below 1 ohms

D31-3 (OX1B) - D74-114 (OX1B)

Always

Below 1 ohms

D31-4 (E1) - D74-115 (EX1B)

Always

Below 1 ohms

D32-1 (HT2B) - D74-44 (HT2B)

Always

Below 1 ohms

D32-3 (OX2B) - D74-112 (OX2B)

Always

Below 1 ohms

D32-4 (E1) - D74-113 (EX2B)

Always

Below 1 ohms

2008 Toyota Tundra

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

Fig. 92: Oxygen Sensor System Diagram

NG : REPAIR OR REPLACE HARNESS OR CONNECTOR

OK : REPLACE HEATED OXYGEN SENSOR (See REMOVAL )

17. READ VALUE USING TECHSTREAM (OUTPUT VOLTAGE OF HEATED OXYGEN

SENSOR)

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/Data List/A/F Control System/O2S B1 S2

or O2S B2 S2.

e. After warming up the engine, run the engine at an engine speed of 2500 RPM for 3 minutes.

f. Engine is idling.

g. Depress the accelerator pedal quickly until the engine speed reaches 2500 RPM 3 times.

Result

RESULT REFERENCE

D31-1 (HT1B) or 074-45 (HT1B) - Body ground

Always

10 kohms or higher

D31-3 (OX1B) or D74-114 (OX1B) - Body ground Always

10 kohms or higher

D32-1 (HT2B) or D74-44 (HT2B) - Body ground

Always

10 kohms or higher

D32-3 (OX2B) or D74-112 (OX2B) - Body ground Always

10 kohms or higher

Result

Proceed To

Higher than 1.2 V

A

2008 Toyota Tundra

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