ENGINE CONTROL (2RZ–FE)

17
B–R B–R B–R
IF1
B Y–GR(A/T)

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

3 1I

1 1

7. 5A STA

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

B
ST1 1
2 2

6 1F 11 1F 2 2 2 1F

Y–GR(A/T)
I14

B–O
Y–GR
G–Y
W–R

IGNITION SW

V
B–O
I3
20 3E
Y–B
22

B–O

B–Y

B–Y

Y–B
3E
B–Y
21 3E

CONNECTOR

CONNECTOR
C

JUNCTION

JUNCTION
23 IF1 B W
W

Y–GR

Y–GR
(M/T)

J11

J11
(A/T)

C B
B–O

Y–B
8 IK3

W
V
(A/T)
B–Y

2 2
W–R

CLUTCH START SW

6 1 1 5
PARK/NEUTRAL
POSITION SW

12 IF1 W–R
P
EFI
2 2 RELAY
N

B–O
P1

2 2 V
5 2 2 3
C9
(A/T)

CIRCUIT OPENING
30A AM2

40A AM1

13 16 7 1 5
G

2 2
CONNECTOR 3

TC BAT SIL
W–R
W–B

21 IK2
DATA LINK

RELAY
CG SG
1 1
(A/T)

D7

C6
G
G

4 5 2 3
1 (M/T)
W–B

W–L
BR

L
120A ALT

5 3E

15 3A 5 BN7
2 8 3E
L

16 3A
G

4
2
F8
23 IK2 FUEL
M
PUMP
W

5
W–B

W–B

W–B
W–L
BR

W–R

BATTERY
D B
J 9 A , J10 B
JUNCTION
CONNECTOR
13 BN7
E A
W–B

W–L
W–B

EA IE EF IG

94
2003 TOYOTA TACOMA (EWD517U)
 1
B–R B–R
IK2
Y–GR(A/T)

B–R B–R B–R

I13 I13 I13
G–Y

B–R

B–R

B–R

B–R

POWER STEERING OIL

STOP LIGHT SW
2 2 2 2 2

INJECTOR NO. 1

INJECTOR NO. 2

INJECTOR NO. 3

INJECTOR NO. 4

PRESSURE SW
S5

P10
I6

I7

I8

I9
1 1 1 1 1 1
G–Y
G–W

7 3F

Y
Y–B
Y–GR(A/T)

W–R

R–L
W

R
19 IK2
15
B–Y 6 3F
IF1
G–W
B–Y

Y–B

Y
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

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

+B EVP TBP FC STA EVG VG THA E2 THW

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

W–R

B–W

G–R
W–L

Y–G

L–B
GR
G

2 IK6
G–B

4 3E 2 3E

ENGINE COOLANT
TEMP. SENSOR
MASS AIR FLOW METER

26 BN7 4 5 2 2
G–B

1 3E 3 3E
W–R

W–R

E3
SWITCHING VALVE)

2 2
VSV (PRESSURE

1
3 1
M1
VSV (EVAP)

7 IF1
I14
V12

W–R
V4

L–B

L–B

L–B

1 1
W–R

W–R

W–R

W–R

W–R

3 BN7
13 IK2 L–B L–B
I13 I13
W–R W–R W–R W–R W–R
I13 I13
W–R
I14 W–R
W–L

W–R

95
2003 TOYOTA TACOMA (EWD517U)
ENGINE CONTROL (2RZ–FE)

FROM POWER SOURCE SYSTEM (SEE PAGE 54)

10A
TAIL

2
I20 I21 I22 I23

FROM CRUISE CONTROL ECU

A25 IGNITION COIL IGNITION COIL IGNITION COIL IGNITION COIL
A/C CONTROL 2 AND IGNITER AND IGNITER AND IGNITER AND IGNITER
ASSEMBLY G NO. 1 NO. 2 NO. 3 NO. 4
TO TACHOMETER
[COMB. METER]

6 1E
4 3 2 3 2 3 2 3 2
G–R
10 9 1F

B–Y

B–Y

B–Y

B–Y
L–R

L–Y
B–L

L
16 3C

B–Y
I13 I13
L–Y

L–B

LG–R
LG–B

20 3C
(*1)

B–Y
G–R

13 A 14 A 13 B 20 A 5 B 11 D 12 D 10 D 13 D 14 D
AC1 ACT TAC ELS IDLO IGT1 IGT2 IGF IGT3 IGT4

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

VTA VC PTNK E04 RSD CCV AFHT AF+ AF– KNK

9 C 2 C 8 B 6 D 15 D 1 C 4 C 11 C 20 C 28 D
G–Y

(SHIELDED)

G–Y
I13
W

8 IK6
W–B

B–R
R–Y

R–L
BR
Y

G–Y

G–Y

VSV (CANISTER CLOSED VALVE)

24 BN7 23 BN7
VAPOR PRESSURE SENSOR

AIR FUEL RATIO SENSOR

G–Y

R–Y

3 1
(SHIELDED)

3 2 2
(BANK 1 SENSOR 1)

3 2 1 3
B

I13
T1 1 1 2 I1 1 2 4
V11

A23
V8

THROTTLE IDLE AIR

L–B

L–B

POSITION CONTROL
SENSOR VALVE
L–B
W–R

W–R

W–R
BR

BR
KNOCK SENSOR

I13 1
25 IK2 25 BN7
L–B
L–B
W–R W–R W–R
K1

I13 I13 BR

W–R W–R
W–B

BR

EF

96
2003 TOYOTA TACOMA (EWD517U)
 FROM POWER SOURCE SYSTEM (SEE PAGE 54)
* 1 : W/ TACHOMETER
* 2 : W/O TACHOMETER

BR
I13 10A
GAUGE

C2 C1
CRANKSHAFT CAMSHAFT
POSITION SENSOR POSITION SENSOR
5 1F
3 BR
E4
G–O

B–R
1 2 2 1
(SHIELDED)

(SHIELDED) 4 3D 19 3D
G

R
L

G–O

BR
5 3D 20 3D 17 3D

I13

G–O

B–R

B–R
G

C10
16 C 24 C 15 C 21 A 3 COMBINATION METER 5
NE+ NE– G2+ SP1

(*2)
(* 1)

INDICATOR LAMP
SPEEDOMETER

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

W–B

W–B

G–R
V–R

V–R

B–R
BR

BR
R–W

L
B

(SHIELDED)
I13

22 IK2 12 IK2

20 IK2 6 IK2 15 IK2

(SHIELDED)

BR
R–W

HEATED OXYGEN SENSOR

B

G–R

B–R
L
(BANK 1 SENSOR 2)

3 1

I15 2 3
4 2
1 B–R
H9
W–R
BR
V

17 3B V10
VEHICLE SPEED
I13 SENSOR
14 IK2 5 IK2
BR

BR

BR

19 3B

BR BR BR
I13 I13
W–R
BR
W–B

W–B

W–B
BR

EF ID

97
2003 TOYOTA TACOMA (EWD517U)
ENGINE CONTROL (2RZ–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 the 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) 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.

98
2003 TOYOTA TACOMA (EWD517U)
2. CONTROL SYSTEM
∗ SFI system
The SFI system monitors the engine conditions through the signals (Input signals (1 to 12) ) 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 HT1B 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.

99
2003 TOYOTA TACOMA (EWD517U)
ENGINE CONTROL (2RZ–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 : Plus generation with vehicle moving
STP–E1 : 7.5–14 volts (Stop light SW on)
IGT1, IGT2–E1 : Plus generator (Cranking or idling)
#10, #20, #30, #40–E1 : 9–14 volts (Ignition 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 (2RZ–FE) F8 37 (Except Double Cab) J10 B 33 (2RZ–FE)
A25 34 H9 35 J11 35
C1 32 (2RZ–FE) I1 33 (2RZ–FE) K1 33 (2RZ–FE)
C2 32 (2RZ–FE) I6 33 (2RZ–FE) M1 33 (2RZ–FE)
C6 34 I7 33 (2RZ–FE) P1 33 (2RZ–FE)
C9 34 I8 33 (2RZ–FE) P10 33 (2RZ–FE)
C10 34 I9 33 (2RZ–FE) S5 35
D7 34 I14 35 T1 33 (2RZ–FE)
E3 32 (2RZ–FE) I20 33 (2RZ–FE) V4 33 (2RZ–FE)
E5 A 35 I21 33 (2RZ–FE) V8 37 (Except Double Cab)
E6 B 35 I22 33 (2RZ–FE) V10 33 (2RZ–FE)
E7 C 35 I23 33 (2RZ–FE) V11 33 (2RZ–FE)
E8 D 35 J9 A 33 (2RZ–FE) V12 37 (Except Double Cab)

100
2003 TOYOTA TACOMA (EWD517U)
 : 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
No.3
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))
IK6
BN7 48 (Except Double Cab) Frame Wire and Cowl Wire (Under the Driver’s Seat)

: GROUND POINTS

Code See Page Ground Points Location

EA 42 (2RZ–FE) Front Left Fender
EF 42 (2RZ–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 (2RZ–FE) Engine Wire I14
44 Cowl Wire
I3 44 Cowl Wire I15
I13 44 Engine Wire

101
2003 TOYOTA TACOMA (EWD517U)