A20056
ECM
STP
ST1–
G–W E5
20
9
L–W
4
3
2
1
E6
3F
3F
7
6
Stop Light Switch
W
J/B No. 3
1F
IGN
AM2
J/B
ALT
2
2
2
2
STOP
1I
1K
1F
2
11
4
6
7
2
G–W
G–Y
B–W
B–R
W–R
B–R
Battery
AM2
IG2
J/B No. 1
R/B No. 2
Ignition
Switch
1
2
1
2
1
DI–702
–
DIAGNOSTICS
CRUISE CONTROL SYSTEM (w/ ETCS–i)
964
Author:
Date:
2003 TOYOTA TACOMA (RM1002U)
DTC
P0571/52 Brake Switch ”A” Circuit
CIRCUIT DESCRIPTION
When the brake pedal is depressed, the stop light switch sends a signal to the ECM. When the ECM receives
this signal, it cancels the cruise control.
A fail–safe function is provided so that the functions normally, even if there is a malfunction in the stop light
signal circuit.
The cancel condition occurs as battery positive voltage is supplied to terminal STP.
When the brake is on, battery positive voltage is normally 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.
DTC Detection Condition
Trouble Area
P0571/52
Stop light switch does not turn off even once the vehicle is
driven (2 trip detection logic)
Short in stop light switch signal circuit
Stop light switch
ECM
WIRING DIAGRAM
DIAUA–01
–
DIAGNOSTICS
CRUISE CONTROL SYSTEM (w/ ETCS–i)
DI–703
965
Author:
Date:
2003 TOYOTA TACOMA (RM1002U)
INSPECTION PROCEDURE
HINT:
Read freeze frame data using the hand–held tester or the OBD II scan tool, as freeze frame data records
the engine conditions when a malfunction is detected. When troubleshooting, it is useful for determining
whether the vehicle was running or stopped, the engine was warmed up or not, the air–fuel ratio was lean
or rich, etc. at the time of the malfunction.
Hand–held tester:
1
Check stop light switch using hand–held tester.
PREPARATION:
Connect the hand–held tester to the DLC3.
(a)
Connect the hand–held tester to the DLC3.
(b)
Turn the ignition switch ON and push the hand–hel