Toyota Celica 2005 Repair Manual page 1302

DTC P0571/52 Brake Switch "A" Circuit
CIRCUIT DESCRIPTION
When the brake pedal is depressed, the stop light switch sends a signal to ECM. When ECM receives this
signal, it cancels the cruise control.
A fail−safe function is provided to maintain normal driving, even if there is a malfunction in the stop light signal
circuit.
The cancel condition occurs when the battery positive voltage is supplied to terminal STP.
When the stop light switch is on, battery positive voltage is applied through the STOP fuse and the stop light
switch to terminal STP of the ECM, and the ECM turns the cruise control OFF.
If the harness connected to terminal STP has an open circuit, terminal STP will have battery positive voltage
and the cruise control will be turned OFF.
DTC No.
Stop Light switch does not turn off even once the vehicle is
P0571/52
driven
WIRING DIAGRAM
J6
J/C
B−O
C C
W
I10
Ignition SW
1
AM1
IG1
B−R
5
AM2 IG2
B−O
Battery
2005 CELICA (RM1131U)
DIAGNOSTICS
DTC Detecting Condition
S8
Stop Light SW
3
4
9
G−W
IK
2
1
2
G−B
IK
5
IK
T0 7
Back−up
IB
Light SW
8
L−R
IK
2
11
B−O
B−R
IK
6
B−R
FL MAIN
− CRUISE CONTROL SYSTEM (2ZZ−GE)
S Stop light switch
S Harness or connector between ECM and stop light switch
circuit
S ECM
R−Y
Instrument Panel J/B
STOP
AM1
BK/UP LP IG1 Relay
6 C
3
1
Engine Room J/B
AM2
16
1
2F
2A
1301
Trouble Area
9 12
R−Y
IE3 E8
6 19
G−W
E8
IB
5
12
W−B
II
2
9
IC
B−R
IF
DI−1101
DIAJR−03
ECM
ST1−
STP
I25314