DESCRIPTION When the brake
pedal is depressed, the stop light switch assembly sends a signal to the
ECM. Upon receiving the signal, the ECM cancels the cruise control
system. |
DTC No. | Detection Item |
DTC Detection Condition | Trouble Area | |
P0571 | Brake Switch "A" Circuit |
When voltage of STP terminal and that of ST1- terminal of ECM are less than 1 V for 0.5 seconds or more |
- Stop light switch assembly
- ECM
- Harness or connector
| WIRING DIAGRAM
 CAUTION / NOTICE / HINT
NOTICE:
- Inspect the fuses for circuits related to this system before performing the following procedure.
- Before replacing the ECM, refer to Registration.
Click here 
PROCEDURE |
1. | CHECK HARNESS AND CONNECTOR (STOP LIGHT SWITCH ASSEMBLY - BATTERY) |
| (a) Disconnect the stop light switch assembly connector. |
 |
|
*a | Front view of wire harness connector
(to Stop Light Switch Assembly) | | |
(b) Measure the voltage according to the value(s) in the table below. Standard Voltage: |
Tester Connection | Condition |
Specified Condition | |
A4-2 - Body ground | Always |
11 to 14 V | |
A4-4 - Body ground | Ignition switch ON |
11 to 14 V | |
A4-4 - Body ground | Ignition switch off |
Below 1 V |
| NG |
 | REPAIR OR REPLACE HARNESS OR CONNECTOR |
|
OK |
 | |
| 2. |
INSPECT STOP LIGHT SWITCH ASSEMBLY | (a) Remove the stop light switch assembly.
Click here (b) Inspect the stop light switch assembly.
Click here
| NG |
| REPLACE STOP LIGHT SWITCH ASSEMBLY |
|
OK | |
| |
| 3. |
CHECK HARNESS AND CONNECTOR (ECM - STOP LIGHT SWITCH ASSEMBLY) |
| (a) Disconnect the ECM connector. |
 |
|
*a | Front view of wire harness connector
(to ECM) | |
*1 | for 1UR-FE | |
*2 | for 3UR-FE | | |
(b) Measure the voltage according to the value(s) in the table below. Standard Voltage (for 1UR-FE): |
Tester Connection | Condition |
Specified Condition | |
A24-35 (ST1-) - Body ground |
Ignition switch ON, brake pedal depressed |
0 to 1.5 V | |
Ignition switch ON, brake pedal released |
7.5 to 14 V | |
A24-36 (STP) - Body ground |
Brake pedal depressed |
7.5 to 14 V | |
Brake pedal released |
0 to 1.5 V | Standard Voltage (for 3UR-FE): |
Tester Connection | Condition |
Specified Condition | |
A24-8 (ST1-) - Body ground |
Ignition switch ON, brake pedal depressed |
0 to 1.5 V | |
Ignition switch ON, brake pedal released |
7.5 to 14 V | |
A24-7 (STP) - Body ground |
Brake pedal depressed |
7.5 to 14 V | |
Brake pedal released |
0 to 1.5 V |
| OK |
| REPLACE ECM |
| NG |
| REPAIR OR REPLACE HARNESS OR CONNECTOR | | 
