I26141
O6 O/D ECU
OD1 7
R–Y*1
(A/T)
*1: 2RZ–FE
*2: Expect 2RZ–FE
ECM
11
E5
*2
8
E8
*2
LG
LG
1
IK3
LG
6
OD
ECT
14
R–Y
(A/T)
C17
Cruise Control ECU
E2
ECT No.2 solenoid
R–Y*2
(A/T)
DI–748
–
DIAGNOSTICS
CRUISE CONTROL SYSTEM (w/o ETCS–i)
1010
Author:
Date:
2003 TOYOTA TACOMA (RM1002U)
Electronically Controlled Transmission Communication Circuit
CIRCUIT DESCRIPTION
When the vehicle is driven uphill under the cruise control, a signal to prevent a upshift until the end of the
uphill slope is sent from the cruise control ECU to the electronically controlled transmission, in order to re-
duce shifting due to ON–OFF overdrive operation and to provide smooth driving when a downshifting in the
electronically controlled transmission occurs.
Terminal ECT of the cruise control ECU detects a shift change signal (input to electronically controlled trans-
mission No. 2 solenoid) from the ECM.
When the vehicle speeds down and when terminal ECT of the cruise control ECU receives a downshifting
signal, it sends a signal from terminal OD to the ECM to cut overdrive until the end of the uphill slope, and
the gear shiftings are reduced and gear shifting points in the electronically controlled transmission are
changed.
WIRING DIAGRAM
DI8ZL–03
I22453
ON
OD
(–)
(+)
–
DIAGNOSTICS
CRUISE CONTROL SYSTEM (w/o ETCS–i)
DI–749
1011
Author:
Date:
2003 TOYOTA TACOMA (RM1002U)
INSPECTION PROCEDURE
1
Check operation of overdrive.
PREPARATION:
Drive the vehicle after the engine warmed up.
CHECK:
Check that overdrive ON ↔ OFF occurs by an operation of the OD switch ON–OFF.
NG
Check and repair electronically controlled
transmission (See page DI–454).
OK
2
Check voltage between terminal OD of cruise control ECU connector and body
ground.
PREPARATION:
(a)
Remove the ECU with the connector being connected.
(b)
Turn the ignition switch ON.
(c)
Disconnect the ECU connector.
CHECK:
Measure the voltage between terminal OD of the ECU connec-
tor and the body ground.
OK:
Voltage: 10 – 16 V
NG
Go to step 5.
OK
I22454
ECT
(–)
(+)
DI–750
–
DIAGNOSTICS
CR