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 MalfunctionOxygen (A/F) Sensor Signal Stuck
HINT:
Although the DTC titles say oxygen sensor, these DTCs relate to the
Air-Fuel Ratio (A/F) sensor.
Sensor 1 refers to the sensor mounted in front of the Three-Way
Catalytic Converter (TWC) and
located near the engine assembly.
DESCRIPTION
The A/F sensor generates a voltage* ...
Cruise Control Switch Circuit
DESCRIPTION
The cruise control main switch operates 8 functions: SET, - (COAST),
TAP-DOWN, RES (RESUME), +
(ACCEL), TAP-UP, CANCEL, and MODE. The SET, TAP-DOWN, and - (COAST) functions,
and the RES
(RESUME), TAP-UP, and + (ACCEL) functions are operated with the same switch. The
cruise contr ...
Disassembly
1. REMOVE NO. 2 FRONT AXLE INBOARD JOINT BOOT LH CLAMP
(a) Using pliers, remove the No. 2 front axle inboard
joint boot LH clamp, as shown in the illustration.
2. REMOVE FRONT AXLE INBOARD JOINT BOOT LH
CLAMP
(a) Remove the front axle inboard joint boot LH clamp
using the same procedures a ...