Toyota COMPUTER-CONTROLLED SYSTEM

ELECTRONIC CONTROL SYSTEM
- Communications Signal s
3 . CRUISE CONTROL SYSTEM
COMMUNICATIONS SIGNA L
This signal is the ignition timing retard request
signal that is sent from the Cruise Control ECU
to the Engine ECU .
ELECTRICAL CIRCUITRY
OHP 4
0
4
. TRC SYSTEM COMMUNICATIONS
SIGNA L
This signal is sent from the TRC ECU to the
Engine ECU to inform it that traction control is in
operation . When the TRC ECU outputs the TR
signal, the Engine ECU executes various types of
corrections related to traction control, such as
retarding the ignition timing .
ELECTRICAL CIRCUITR Y
TRC ECU
Engine EC
U
OHP 40
5 . ABS (ANTI-LOCK BRAKE SYSTEM)
COMMUNICATIONS SIGNA L
This signal detects when the ABS system is
operating . It is used in fuel cut-off control to
reduce the effectiveness of engine braking as
necessary .
ELECTRICAL CIRCUITR Y
ABS ECU
Engine EC U
OHP 4
0
6 . INTERCOOLER SYSTEM WARNING
SIGNA L
When trouble occurs in the intercooler system in
vehicles equipped with a turbocharging system
having a water-cooled type intercooler, the
Intercooler ECU sends this signal to the Engine
ECU, which lights the "CHECK ENGINE" lamp .
ELECTRICAL CIRCUITR Y
Intercooler
ECU
Engine EC U
OHP 40
46