DTC P0571 Brake Switch "A" 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. The fail-safe function operates to enable normal driving even if there is a malfunction in the stop light signal circuit. The cancellation condition occurs when voltage is applied to terminal STP. When the brake is applied, voltage is normally applied to terminal STP of the ECM through the STOP fuse and the stop light switch, and the ECM turns the cruise control off.
|
DTC No. |
DTC Detection Condition |
Trouble Area |
|
P0571 |
Voltage of STP terminal and that of ST1- terminal of ECM are less than 1 V for 0.5 sec. or more. |
|
WIRING DIAGRAM

INSPECTION PROCEDURE
1 READ VALUE OF INTELLIGENT TESTER
ECM (Cruise control):

OK: When the brake pedal is operated, the display changes as shown above.
REPLACE ECM
2 CHECK HARNESS AND CONNECTOR (STOP LIGHT SWITCH - BATTERY)

Standard voltage

3 INSPECT STOP LIGHT SWITCH

Standard resistance

4 CHECK ECM

Standard voltage

REPLACE ECM
Vehicle Speed Sensor Malfunction
Input Signal Circuit MalfunctionOn-vehicle inspection
1. INSPECT FRONT AXLE HUB BEARING BACKLASH
(a) Using a dial gauge, check for backlash near the
center of the axle hub.
Maximum:
0.05 mm (0.0020 in.)
If backlash exceeds the maximum, replace the
bearing.
NOTICE:
Ensure that the dial gauge is set at right angles
to the measurement surface ...
VSC Warning Light Remains ON
DESCRIPTION
The skid control ECU is connected to the combination meter via CAN and
multiplex communications.
If the skid control ECU stores DTCs to shut down TRAC and VSC operation, the VSC
warning light comes
on in the combination meter.
WIRING DIAGRAM
INSPECTION PROCEDURE
NOTICE:
...
Disassembly
1. Remove repair service starter kit
(a) Remove the nut and disconnect the lead wire from
the repair service starter kit.
(b) Remove the 2 screws which are used to secure the
repair service starter kit to the repair service starter
kit.
(c) Remove the repair service starter kit.
( ...