Toyota Celica 2005 Repair Manual page 758

4 Check STP signal and ST1− voltage.
ON
Brake Pedal
Depressed
ST1−
( )
NG
5 Check harness and connector between ECM and stop light switch (See page
IN−30).
OK
Replace ECM (See page SF−78).
2005 CELICA (RM1131U)
DIAGNOSTICS
PREPARATION:
(a)
(b)
Brake Pedal
Release
(c)
CHECK:
(a)
(b)
OK:
STP
A19642
( )
− ENGINE (2ZZ−GE)
Connect the to the DLC3.
Turn the ignition switch ON and hand−held tester main
switch ON.
Enter the following menu: "DIAGNOSIS / ENHANCED
OBD II / DATA LIST / ALL / STOP LIGHT SW".
Read the STP signal on the hand−held tester.
Measure the voltage between terminals ST1− and body
ground.
Brake Pedal
Depressed
Released
OK Check for intermittent problems (See page
DI−295).
NG Repair or replace harness or connector.
757
STP Signal ST1− Voltage
ON Below 1.5 V
OFF
DI−559
7.5 to 14 V