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
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Short in CAN Bus Lines
DESCRIPTION
The CAN bus wires are considered to be shorted when the resistance between
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Symptom
Trouble Area
Resistance between terminals 6 (CANH) and 14 (CANL) of the DLC3
is below 54 Ω.
...