ENGINE CONTROL (3RZ–FE)

17
B–R B–R B–R
IF1
B B–Y(A/T)

7 AM2 IG2 6 FROM POWER SOURCE SYSTEM (SEE PAGE 54)

3 1I

1 1

ACC
7. 5A 7. 5A 20A 7. 5A 10A
STA IGN EFI OBD STOP
2 AM1 IG1

ST1 1
2 2

6 1F 11 1F 2 2 2 1F
I14

(A/T)

B–O
B–Y

B–Y
W–R

IGNITION SW
G–Y
20 3E

B–Y

B–Y

V
23 IF1
22
R
3E

B–O
21 3E 2 2 B–Y

B–Y 1 5
(A/T) B W
EFI 12 IF1
J11
(M/T)

8 IK3 RELAY
B–Y

B JUNCTION
CONNECTOR
(A/T)
B–Y

2 3
CLUTCH START SW

9 1 2 2
PARK/NEUTRAL

V
POSITION SW

P W–R W–R
W–B
W–R

N W–R
P1

I3
6 2
C9

W–R

W–R
B–W
(A/T)

W
R

V
2 2

2 2 21 IK2 13 16 7 1 5
TC BAT SIL
D7
30A AM2

40A AM1

OPENING
CIRCUIT
B–W
(A/T)

DATA LINK

RELAY
B–W
CONNECTOR 3
TAC CG SG

C6
(M/T)
9 4 5 2 3
1 1 5 3E
LG–B

1
W–B

W–L

L
120A ALT

8 3E
BR

9 BN1
B–W

FROM COMBINATION

15 3A
L

2
4
METER

FUEL PUMP
W–B

16 3A
W

M
W–L

F8

23 IK2
5
J 9 A , J10 B

W–B

W–B

D B
BR
CONNECTOR

25 IK2
JUNCTION

BATTERY

6 BN1
W–L

E A
W–B

W–L
W–B

B–W

EA IE EF IG

2001 TOYOTA TACOMA (EWD440U)

78
 1
B–R B–R
IK2
B–Y(A/T)

B–R B–R B–R

I13 I13 I13
G–Y

B–R

B–R

B–R

B–R

OIL PRESSURE SW
STOP LIGHT SW

POWER STEERING
2 2 2 2 2

INJECTOR NO. 1

INJECTOR NO. 2

INJECTOR NO. 3

INJECTOR NO. 4
G–Y

S5

P10
I6

I7

I8

I9
1 1 1 1 1 1

G–Y
G–W

5
R R 7 3F
B–Y(A/T)
IK2

W–R

R–L
W

Y
15
B–Y B–Y
IF1
6 3F
G–W

12 A 1 A 7 B 15 A 22 A 1 D 2 D 3 D 4 D 28 B
SIL BATT TC STP NSW # 10 # 20 # 30 # 40 PSSW

W–R
E5 A , E6 B , E7 C , E8 D
W–R ENGINE CONTROL MODULE
W–R

EVP TPC +B FC STA EVG VG THA E2 THG THW

7 IF1 6 C 7 C 16 A 6 B 7 A 22 C 14 C 21 C 18 C 19 C 12 C
W–G
W–R

W–R

B–W

B–W

G–R
W–L

Y–G
G–B

P–L
GR

LG

EGR GAS TEMP. SENSOR

ENGINE COOLANT
4 3E 1 3E

TEMP. SENSOR
MASS AIR FLOW METER

4 5 2 2 2
2
W–R
3E
E3

3 3E
E1

1 1
PRESSURE SENSOR)
W–R

3 1
M1

2 2
VSV (VAPOR
VSV (EVAP)

I14
W–R

LG

LG

LG

LG
W–R

V4

V9

1 1
W–R

W–R

W–R

13 IK2
W–R

LG LG LG
I13 I13 I13
W–R W–R W–R W–R
I13 I13 I13
W–R
W–L

B–W

W–R

2001 TOYOTA TACOMA (EWD440U)

79
ENGINE CONTROL (3RZ–FE)

(TRANSFER L4 POSITION)
I20 I21 I22 I23

TO ADD DETECTION SW
A25 IGNITION IGNITION IGNITION IGNITION
A/C CONTROL COIL AND COIL AND COIL AND COIL AND

TO DETECTION SW
ASSEMBLY IGNITER NO. 1 IGNITER NO. 2 IGNITER NO. 3 IGNITER NO. 4

TO TACHOMETER
[ADD ACTUATOR]

[COMB. METER]
10 9 3 2 3 2 3 2 3 2

B–Y

B–Y

B–Y

B–Y
LG–B
(* 1)
B–Y
I13 I13
(4WD A/T)
(4WD)
G–B

11 IK2
L–Y

L–B

GR

LG–B

B–Y

L–R

L–Y
B–L
(* 1)

L
13 A 14 A 10 B 19 A 13 B 11 D 12 D 10 D 13 D 14 D
AC1 ACT 4WD L4 TAC IGT1 IGT2 IGF IGT3 IGT4

E5 A , E6 B , E7 C , E8 D
ENGINE CONTROL MODULE

IDLO VTA VC PTNK E04 RSD EGR AFHT AF+ AF– KNK
5 B 9 C 2 C 8 B 6 D 15 D 5 C 4 C 11 C 20 C 28 D
W–B
G–Y
LG–R

(SHIELDED)
B–R
R–Y

R–B

W
Y

B
I13
BR
TO CRUISE CONTROL ECU

G–Y

G–Y

D1
DATA LINK
3 1 1 CONNECTOR 1
AIR FUEL RATIO SENSOR

3 2 3 2
(SHIELDED)
VSV (EGR)

1 3
(BANK 1 SENSOR 1)

+B E1
V3

I13
2 12 3
T1 1 V8 1 2 I1 2 4
THROTTLE VAPOR IDLE AIR
KNOCK SENSOR

POSITION PRESSURE CONTROL VALVE

A23

1
SENSOR SENSOR
W–R

W–R

W–R

W–R
BR
LG

LG

BR
K1

LG
I13
W–R W–R W–R W–R
I13 I13 I13
W–R BR BR
I13
W–B

BR

W–R W–R

EF

2001 TOYOTA TACOMA (EWD440U)

80
 FROM POWER SOURCE SYSTEM (SEE PAGE 54) * 1 : W/ TACHOMETER FROM POWER SOURCE SYSTEM (SEE PAGE 54)
* 2 : W/O TACHOMETER

BR
10A I13 10A
TAIL GAUGE

C2 C1
2 CRANKSHAFT CAMSHAFT
POSITION SENSOR POSITION SENSOR
2 5 1F
3 BR
G

E4
G–O

B–R
6 1E 1 2 2 1
(SHIELDED)

(SHIELDED) 4 3D 19 3D
G

R
4 1F
L
G–R

G–O

BR
16 3C
5 3D 20 3D 17 3D

I13

G–O
20 3C

B–R

B–R
G–R

20 A 16 C 24 C 15 C 21 A 3 5
ELS NE+ NE– G2+ SP1
(* 1)

(* 2)

INDICATOR LAMP
SPEEDOMETER
COMBINATION METER

MALFUNCTION
CONTROL
E5 A , E6 B , E7 C , E8 D CIRCUIT
ENGINE CONTROL MODULE
(* 2)
C10

(* 2)

(* 1)

(* 1)
OXS HTS E1 E01 E02 E03 W
7 8 2 9
10 C 3 C 17 C 21 D 31 D 5 D 6 A
(SHIELDED)

R–W

W–B

W–B

W–B

G–R
V–R

V–R

B–R
BR

BR

L
B

12 IK2 4 IK7
20 IK2 6 IK2 15 IK2
(SHIELDED)

R–W

G–R
B

BR

P
L
HEATED OXYGEN SENSOR

3 1
(BANK 1 SENSOR 2)

I15

4 2
BR

W–R
BR

H9

2 3 1
14 IK2 17 3B
BR

BR

BR
I13
BR

BR

10 IK7 19 3B
BR V10
BR

I13 I13
VEHICLE SPEED SENSOR
BR BR
BR
W–B

W–B

W–B

I13
BR

W–R

EF ID

2001 TOYOTA TACOMA (EWD440U)

81
ENGINE CONTROL (3RZ–FE)
SYSTEM OUTLINE
The engine control system utilizes a microcomputer and maintains overall control of the engine, transmission, etc. An outline
of engine control is given here.
1. INPUT SIGNAL
(1) Engine coolant temp. signal system
The engine coolant temp. sensor detects the engine coolant temp. and has a built–in thermistor with a resistance which
varies according to the water temp. Thus the engine coolant temp. is input in the form of a control signal to TERMINAL
THW of the engine control module.
(2) Intake air temp. signal system
The intake air temp. sensor is installed inside the mass air flow meter and detects the intake air temp., which is input as
a control signal to TERMINAL THA of the engine control module.
(3) Heated oxygen sensor signal system
The oxygen density in exhaust emissions is detected and input as a control signal to TERMINAL OXS of the engine
control module. To maintain stable detection performance by the heated oxygen sensor, a heater is used for warming
the sensor. The heater is also controlled by the engine control module (HTS).
(4) RPM signal system
Camshaft position and crankshaft position are detected by the camshaft position sensor and crankshaft position sensor,
camshaft position is input as a control signal to TERMINAL G2+ of the engine control module, and engine RPM is input
to TERMINAL NE+.
(5) Throttle signal system
The throttle position sensor detects the throttle valve opening angle, which is input as a control signal to TERMINAL VTA
of the engine control module.
(6) Vehicle speed signal system
The vehicle speed sensor detects the vehicle speed and inputs a control signal to TERMINAL SP1 of the engine control
module via the combination meter.
(7) A/C SW signal system
The operating voltage of the A/C magnetic clutch is detected and input in the form of a control signal to TERMINAL AC1
of the engine control module.
(8) Battery signal system
Voltage is constantly applied to TERMINAL BATT of the engine control module. When the ignition SW is turned to on,
voltage for engine control module operation is applied via the EFI relay to TERMINAL +B of the engine control module.
(9) Intake air volume signal system
Intake air volume is detected by the mass air flow meter and a signal is input into TERMINAL VG of the engine control
module as a control signal.
(10) Stop light SW signal system
The stop light SW is used to detect whether or not the vehicle is braking and the information is input as a control signal
to TERMINAL STP of the engine control module.
(11) Starter signal system
To confirm that the engine is cranking, the voltage applied to the starter motor during cranking is detected and is input as
a control signal to TERMINAL STA of the engine control module.
(12) Engine knock signal system
Engine knocking is detected by the knock sensor and input as a control signal to TERMINAL KNK of the engine control
module.
(13) 4WD signal system
Whether or not the vehicle is operating in 4WD mode is determined, and a control signal is input to TERMINAL 4WD of
the engine control module.
(14) Air fuel ratio signal system
The air fuel ratio is detected and input as a control signal into TERMINAL AF+ of the engine control module.

2001 TOYOTA TACOMA (EWD440U)

82
2. CONTROL SYSTEM
∗ SFI system
The SFI system monitors the engine conditions through the signals (Input signals (1 to 13) ) input from each sensor to
the engine control module. Based on this data and the program memorized in the engine control module, the most
appropriate fuel injection timing is decided and current is output to TERMINALS #10, #20, #30 and #40 of the engine
control module, causing the injectors to operate (to inject fuel). It is this system which, through the work of the engine
control module, finely controls fuel injection in response to driving conditions.
∗ Electronic spark advance system
The ESA system monitors the engine conditions using the signals (input signals (1, 4, 5 to 7, 9, 11, 12) ) input to the
engine control module from each sensor. Based on this data and the program memorized in the engine control module,
the most appropriate ignition timing is decided and current is output to TERMINALS IGT1, IGT2, IGT3 and IGT4 of the
engine control module. This output controls the igniter to produce the most appropriate ignition timing for the driving
conditions.
∗ Heated oxygen sensor heater control system
The heated oxygen sensor heater control system turns the heater to on when the intake air volume is low (Temp. of
exhaust emissions low), and warms up the heated oxygen sensor to improve detection performance of the sensor. The
engine control module evaluates the signals (Input signals (1, 4, 8, 9, 11) ) from each sensor, current is output to
TERMINAL HTS and controls the heater.
3. DIAGNOSIS SYSTEM
With the diagnosis system, when there is a malfunction in the ECU signal system, the malfunctioning system is recorded in
the memory. The malfunctioning system can then be found by reading the display (Code) of the malfunction indicator lamp.
4. FAIL–SAFE SYSTEM
When a malfunction occurs in any system, if there is a possibility of engine trouble being caused by continued control based
on the signals from that system, the fail–safe system either controls the system by using data (Standard values) recorded in
the engine control module memory or else stops the engine.

2001 TOYOTA TACOMA (EWD440U)

83
ENGINE CONTROL (3RZ–FE)
SERVICE HINTS
EFI RELAY
5–3 : Closed with ignition SW at ON or ST position
C6 CIRCUIT OPENING RELAY
5–3 : Closed with starter running or ignition SW at ON or ST position
I6, I7, I8, I9 INJECTOR
1–2 : 13.4–14.2 Ω
T1 THROTTLE POSITION SENSOR
2–1 : 4–9 kΩ
E3 ENGINE COOLANT TEMP. SENSOR
1–2 : 10–20 kΩ (–20°C, –4°F)
4–7 kΩ (0°C, 32°F)
2–3 kΩ (20°C, 68°F)
0.9–1.3 kΩ (40°C, 104°F)
0.4–0.7 kΩ (60°C, 140°F)
0.2–0.4 kΩ (80°C, 176°F)
E5 (A), E6 (B), E7 (C), E8 (D) ENGINE CONTROL MODULE
Voltage at engine control module wiring connectors
+B–E1 : 9–14 volts (Ignition SW on)
BATT–E1 : 9–14 volts (Always)
VC–E2 : 4.5–5.5 volts (Ignition SW on )
VTA–E2 : 0.3–0.8 volts (Ignition SW on and throttle valve fully closed)
3.2–4.9 volts (Ignition SW on and throttle valve fully open)
STA–E1 : 6 volts or more (Ignition SW at ST position)
W–E1 : 9–14 volts (No trouble and engine running)
THA–E2 : 0.5–3.4 volts (Ignition SW on and intake air temp. 20°C, 68°F)
THW–E2 : 0.2–1.0 volts (Ignition SW on and coolant temp. 80°C, 176°F)
SP1–E1 : Pulse generation with vehicle moving
STP–E1 : 7.5–14 Volts (Stop light SW on)
RESISTANCE AT ECU WIRING CONNECTOR
(Disconnect wiring connector)
VTA–E2 : 3.3–10 kΩ (Throttle valve fully open)
0.2–0.8 kΩ (Throttle valve fully closed)
THA–E2 : 2–3 kΩ (Intake air temp. 20°C, 68°F)
THW–E2 : 0.2–0.4 kΩ (Coolant temp. 80°C, 178°F)
+B–E1 : 0.2–0.4 kΩ
NE+–E1 : 140–180 Ω

: PARTS LOCATION
Code See Page Code See Page Code See Page
A23 32 (3RZ–FE) E8 D 35 J9 A 33 (3RZ–FE)
A25 34 36 (Double Cab) J10 B 33 (3RZ–FE)
F8
C1 32 (3RZ–FE) 37 (Except Double Cab) J11 35
C2 32 (3RZ–FE) H9 35 K1 33 (3RZ–FE)
C6 34 I1 33 (3RZ–FE) M1 33 (3RZ–FE)
C9 34 I6 33 (3RZ–FE) P1 33 (3RZ–FE)
C10 34 I7 33 (3RZ–FE) P10 33 (3RZ–FE)
D1 32 (3RZ–FE) I8 33 (3RZ–FE) S5 35
D7 34 I9 33 (3RZ–FE) T1 33 (3RZ–FE)
E1 32 (3RZ–FE) I14 35 V3 33 (3RZ–FE)
E3 32 (3RZ–FE) I20 33 (3RZ–FE) V4 33 (3RZ–FE)
E5 A 35 I21 33 (3RZ–FE) V8 33 (3RZ–FE)
E6 B 35 I22 33 (3RZ–FE) V9 33 (3RZ–FE)
E7 C 35 I23 33 (3RZ–FE) V10 33 (3RZ–FE)

2001 TOYOTA TACOMA (EWD440U)

84
 : RELAY BLOCKS

Code See Page Relay Blocks (Relay Block Location)

2 21 R/B No.2 (Engine Compartment Left)
,,,
,,,
,,,
: JUNCTION BLOCK AND WIRE HARNESS CONNECTOR

Code See Page Junction Block and Wire Harness (Connector Location)
1E 23 Engine Room Main Wire and J/B No.1 (Lower Finish Panel)
1F 23 Cowl Wire and J/B No.1 (Lower Finish Panel)
1I 23 Engine Room Main Wire and J/B No.1 (Lower Finish Panel)
3A
3B
3C
24 Cowl Wire and J/B No.3
No 3 (Behind the Instrument Panel Left)
3D
3E
3F

: CONNECTOR JOINING WIRE HARNESS AND WIRE HARNESS

Code See Page Joining Wire Harness and Wire Harness (Connector Location)
IF1 44 Engine Room Main Wire and Cowl Wire (Left Kick Panel)
IK2
IK3 44 Engine
g Wire and Cowl Wire ((Above the Glove Box))
IK7
46 (Double Cab)
BN1 Frame Wire and Cowl Wire (Under the Driver’s Seat)
48 (Except Double Cab)

: GROUND POINTS

Code See Page Ground Points Location

EA 42 (3RZ–FE) Front Left Fender
EF 42 (3RZ–FE) Ignition Coil Braket
ID 44 Left Kick Panel
IE 44 Around the Right Edge of the Reinforcement
IG 44 Around the Left Edge of the Reinforcement

: SPLICE POINTS

Code See Page Wire Harness with Splice Points Code See Page Wire Harness with Splice Points
E4 42 (3RZ–FE) Engine Wire I14
44 Cowl Wire
I3 44 Cowl Wire I15
I13 44 Engine Wire

2001 TOYOTA TACOMA (EWD440U)

85