A00038
EFI
AM2
ALT
AM1
IG Switch
Battery
Starter Relay
Park/Neutral
Position
Switch (A/T)
From
Camshaft
Position
Sensor
Clutch
Start
Switch
(M/T)
(NE Signal)
(STA Signal)
Starter
IG
ST
EFI Relay
Circuit Opening
Relay
Fuel Pump
ECM
FC
STA
NE
Tr
DI–210
–
DIAGNOSTICS
ENGINE (2RZ–FE, 3RZ–FE)
472
Author:
Date:
2003 TOYOTA TACOMA (RM1002U)
Fuel Pump Control Circuit
CIRCUIT DESCRIPTION
In the diagram below, when the engine is cranked, current flows from terminal ST of the ignition switch to
the starter relay coil and also current flows to terminal STA of ECM (STA signal).
When the STA signal and NE signal are input to the ECM, Tr is turned ON, current flows to coil of the circuit
opening relay, the relay switches on, power is supplied to the fuel pump and the fuel pump operates.
While the NE signal is generated (engine running), the ECM keeps Tr ON (circuit opening relay ON) and the
fuel pump also keeps operating.
DI9TR–02
A20076
W–L
2
J/B No. 1
R/B No. 2
ECM
IGN
7
6
AM2
Battery
I14
Ignition
Switch
IG
1F
11
4
1I
1
E6
B–O
IF1
7
13
B–R
W
4
2
2
J/B No. 3
5
BN7
5 BN7
3E
3E
1
4
6
FC
W–B
W–B
L
L
W–R
W–R
W–R
1
2
3
5
F8
Fuel Pump
W–R
C6
Circuit
Opening
Relay
From
Terminal 3 of EFI Relay
(See page DI–206)
E01
BE6653
P25111
A00094
ON
Fuel Return Hose
–
DIAGNOSTICS
ENGINE (2RZ–FE, 3RZ–FE)
DI–211
473
Author:
Date:
2003 TOYOTA TACOMA (RM1002U)
WIRING DIAGRAM
INSPECTION PROCEDURE
Hand–held tester:
1
Connect hand–held tester, and check operation of fuel pump.
PREPARATION:
(a)
Connect the hand–held tester to the DLC3.
(b)
Turn the ignition switch ON and push the hand–held tes-
ter main switch ON.
(c)
Select the item ”DIAGNOSIS/ENHANCED OBD II/AC-
TIVE TEST/FUEL PUMP/SPD”.
(d)
Use the ACTIVE TEST mode to operate the fuel pump.
CHECK:
Check for fuel pressure in the fuel return hose when it is pinched
off.
OK:
There is pressure in the fuel return hose.
HINT:
At this time, you will hear a fuel flowing noise.
A18845
FC (+)
DI–212
–
DIAGNOSTICS
ENGINE (2RZ–FE, 3RZ–FE)
474
Author:
Date:
2003 TOYOTA TACOMA (RM1002U)
O