Toyota Tundra. Manual — part 1305

Engine cranks normally but
difficult to start

CIRCUIT

Compression

ON-VEHICLE

INSPECTION

Difficult to start with cold
engine

Ignition system

ON-VEHICLE

INSPECTION

Spark plug

ON-VEHICLE

INSPECTION

Fuel pump control circuit

FUEL PUMP CONTROL

CIRCUIT

Injector

INSPECTION

Difficult to start with warm
engine

Injector

INSPECTION

Ignition system

ON-VEHICLE

INSPECTION

Spark plug

ON-VEHICLE

INSPECTION

Fuel pump control circuit

FUEL PUMP CONTROL

CIRCUIT

High engine idle speed

Electronic throttle control system

THROTTLE BODY

A/C signal circuit (for Automatic Air
Conditioning System)

TERMINALS OF ECU

A/C signal circuit (for Manual Air
Conditioning System)

TERMINALS OF ECU

ECM power source circuit

ECM POWER SOURCE

CIRCUIT

Acoustic Control Induction System
(ACIS)

ACIS CONTROL CIRCUIT

Low engine idle speed (Poor
idling)

Electronic throttle control system

THROTTLE BODY

A/C signal circuit (for Automatic Air
Conditioning System)

TERMINALS OF ECU

A/C signal circuit (for Manual Air
Conditioning System)

TERMINALS OF ECU

Fuel pump control circuit

FUEL PUMP CONTROL

CIRCUIT

Air induction system

ON-VEHICLE

INSPECTION

Acoustic Control Induction System
(ACIS)

ACIS CONTROL CIRCUIT

PCV hose

ON-VEHICLE

INSPECTION

Compression

ON-VEHICLE

INSPECTION

Spark plug

ON-VEHICLE

INSPECTION

Injector

INSPECTION

2008 Toyota Tundra

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

Rough idling

Ignition system

ON-VEHICLE

INSPECTION

Fuel pump control circuit

FUEL PUMP CONTROL

CIRCUIT

Electronic throttle control system

THROTTLE BODY

Air induction system

ON-VEHICLE

INSPECTION

Acoustic Control Induction System
(ACIS)

ACIS CONTROL CIRCUIT

PCV hose

ON-VEHICLE

INSPECTION

Mass air flow meter

MASS AIR FLOW METER

Idle hunting

Electronic throttle control system

THROTTLE BODY

Air induction system

ON-VEHICLE

INSPECTION

ECM power source circuit

ECM POWER SOURCE

CIRCUIT

Acoustic Control Induction System
(ACIS)

ACIS CONTROL CIRCUIT

Hesitation/Poor acceleration

Fuel pump control circuit

FUEL PUMP CONTROL

CIRCUIT

Spark plug

ON-VEHICLE

INSPECTION

Ignition system

ON-VEHICLE

INSPECTION

Injector

INSPECTION

Mass air flow meter

MASS AIR FLOW METER

Electronic throttle control system

THROTTLE BODY

Air induction system

ON-VEHICLE

INSPECTION

Compression

ON-VEHICLE

INSPECTION

Surging (Poor driveability)

Spark plug

ON-VEHICLE

INSPECTION

Fuel pump control circuit

FUEL PUMP CONTROL

CIRCUIT

Ignition system

ON-VEHICLE

INSPECTION

Injector

INSPECTION

Mass air flow meter

MASS AIR FLOW METER

Variable valve timing system

CAMSHAFT OIL

CONTROL VALVE

Compression

ON-VEHICLE

INSPECTION

2008 Toyota Tundra

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

TERMINALS OF ECM

1. CHECK ECM

Fig. 15: Identifying Terminals Of ECM

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

HINT:

Engine stalls soon after starting

Fuel pump control circuit

FUEL PUMP CONTROL

CIRCUIT

Spark plug

ON-VEHICLE

INSPECTION

Ignition system

ON-VEHICLE

INSPECTION

Injector

INSPECTION

Variable valve timing system

CAMSHAFT OIL

CONTROL VALVE

Electronic throttle control system

THROTTLE BODY

Air induction system

ON-VEHICLE

INSPECTION

PCV hose

ON-VEHICLE

INSPECTION

Compression

ON-VEHICLE

INSPECTION

Engine stalls only during A/C
operation

A/C signal circuit (for Automatic Air
Conditioning System)

TERMINALS OF ECU

A/C signal circuit (for Manual Air
Conditioning System)

TERMINALS OF ECU

ECM

TERMINALS OF ECM

Unable/difficult to refuel

Refueling valve (canister)

-

2008 Toyota Tundra

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

The standard normal voltage between each pair of ECM terminals is shown in the table below. The
appropriate conditions for checking each pair of terminals are also indicated. The result of checks
should be compared with the standard normal voltage for that pair of terminals, displayed in the
Specified Condition column. The illustration above can be used as a reference to identify the ECM
terminal locations.

CONNECTOR TERMINAL WIRING COLOR REFERENCE

Terminal No.

(Symbols)

Wiring

Color

Terminal Description

Condition

Specified

Condition

A24-1 (BATT)

- D74-81 (E1)

L - BR

Battery (for measuring
battery voltage and for
ECM memory)

Always

11 to 14 V

D74-41 (+BM)

- D74-81 (E1)

P - BR

Power source of throttle
actuator

Always

11 to 14 V

A24-28

(IGSW) - D74-

81 (E1)

LG - BR Ignition switch

Ignition switch ON

11 to 14 V

A24-3 (+B) -

D74-81 (E1)

GR - BR Power source of ECM

Ignition switch ON

11 to 14 V

A24-2 (+B2) -

D74-81 (E1)

GR - BR Power source of ECM

Ignition switch ON

11 to 14 V

D74-58 (OC1+)
- D74-57 (OC1-

)

B-B-L

Camshaft timing oil
control valve (OCV)

Ignition switch ON

Pulse generation

(See awaveform

1)

D74-52 (OC2+)
- D74-51 (OC2-

)

L-B - R-B

Camshaft timing oil
control valve (OCV)
(Intake side (for bank 2))

Ignition switch ON

Pulse generation

(See awaveform

1)

A24-34

(MREL) - D74-

81 (E1)

W - BR EFI relay

Ignition switch ON

11 to 14 V

D74-74 (VG) -

D74-75 (E2G)

L-Y - G-W Mass air flow meter

Idling, Shift lever
position P or N, A/C
switch OFF

0.5 to 3.0 V

D74-73 (THA)

- D74-97

(ETHW)

Y-B - BR

Intake air temperature
sensor

Idling, Intake air
temperature 20°C (68°F)

0.5 to 3.4 V

D74-76 (THW)

- D74-97

(ETHW)

G-B - BR

Engine coolant
temperature sensor

Idling, Engine coolant
temperature 80°C (176°
F)

0.2 to 1.0 V

D74-80

(VCTA) - D74-

79 (ETA)

L - Y

Power source of throttle
position sensor (specific
voltage)

Ignition switch ON

4.5 to 5.5 V

D74-78

(VTA1) - D74-

79 (ETA)

R - Y-Y

Throttle position sensor
(for engine control)

Ignition switch ON,
Throttle valve fully
closed

0.5 to 1.2 V

Ignition switch ON,

2008 Toyota Tundra

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