DESCRIPTION
When the brake pedal is depressed, the stop light switch assembly 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. Cruise control cancellation 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 assembly, and the ECM turns the cruise control off.
DTC |
DTC Detection Condition |
Trouble Area |
---|---|---|
P0571 |
Voltage of STP signal and that of ST1- signal of ECM are less than 1 V for 0.5 seconds or more |
|
WIRING DIAGRAM
CAUTION / NOTICE / HINT
HINT:
Inspect the fuses for circuits related to this system before performing the following inspection procedure.
PROCEDURE
1. |
INSPECT STOP LIGHT SWITCH ASSEMBLY (POWER SOURCE) |
(a) Disconnect the stop light switch assembly connector. |
|
(b) Measure the voltage according to the value(s) in the table below.
Standard Voltage:
Tester Connection |
Condition |
Specified Condition |
---|---|---|
A35-2 - Body ground |
Always |
11 to 14 V |
*1 |
Front view of wire harness connector (to Stop Light Switch Assembly) |
(c) Reconnect the stop light switch assembly connector.
NG | ![]() |
REPAIR OR REPLACE HARNESS OR CONNECTOR (STOP LIGHT SWITCH ASSEMBLY - BATTERY) |
|
2. |
INSPECT STOP LIGHT SWITCH ASSEMBLY (POWER SOURCE) |
(a) Disconnect the stop light switch assembly connector. |
|
(b) Turn the ignition switch to ON.
(c) Measure the voltage according to the value(s) in the table below.
Standard Voltage:
Tester Connection |
Switch Condition |
Specified Condition |
---|---|---|
A35-4 - Body ground |
Ignition switch ON |
11 to 14 V |
*1 |
Front view of wire harness connector (to Stop Light Switch Assembly) |
(d) Reconnect the stop light switch assembly connector.
NG | ![]() |
REPAIR OR REPLACE HARNESS OR CONNECTOR (STOP LIGHT SWITCH ASSEMBLY - IGN FUSE) |
|
3. |
INSPECT STOP LIGHT SWITCH ASSEMBLY |
(a) Remove the stop light switch assembly (See page
|
|
(b) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
Tester Connection |
Switch Condition |
Specified Condition |
---|---|---|
1 - 2 |
Switch pin not pushed |
Below 1 Ω |
3 - 4 |
Switch pin not pushed |
10 kΩ or higher |
1 - 2 |
Switch pin pushed |
10 kΩ or higher |
3 - 4 |
Switch pin pushed |
Below 1 Ω |
(c) Reinstall the stop light switch assembly (See page
).
NG | ![]() |
REPLACE STOP LIGHT SWITCH ASSEMBLY |
|
4. |
CHECK HARNESS AND CONNECTOR (ECM - STOP LIGHT SWITCH ASSEMBLY) |
(a) Disconnect the ECM connector. |
|
(b) Disconnect the stop light switch assembly connector.
(c) Measure the resistance according to the value(s) in the table below.
Standard Resistance (Check for Open):
For 1AR-FE
Tester Connection |
Condition |
Specified Condition |
---|---|---|
A49-29 (STP) - A35-1 |
Always |
Below 1 Ω |
A49-39 (ST1-) - A35-3 |
Always |
Below 1 Ω |
Tester Connection |
Condition |
Specified Condition |
---|---|---|
A41-36 (STP) - A35-1 |
Always |
Below 1 Ω |
A41-35 (ST1-) - A35-3 |
Always |
Below 1 Ω |
Standard Resistance (Check for Short):
For 1AR-FE
Tester Connection |
Condition |
Specified Condition |
---|---|---|
A49-29 (STP) or A35-1 - Body ground |
Always |
10 kΩ or higher |
A49-39 (ST1-) or A35-3 - Body ground |
Always |
10 kΩ or higher |
Tester Connection |
Condition |
Specified Condition |
---|---|---|
A41-36 (STP) or A35-1 - Body ground |
Always |
10 kΩ or higher |
A41-35 (ST1-) or A35-3 - Body ground |
Always |
10 kΩ or higher |
*1 |
Front view of wire harness connector (to Stop Light Switch Assembly) |
*2 |
Front view of wire harness connector (to ECM) |
*3 |
for 1AR-FE |
*4 |
for 2GR-FE |
(d) Reconnect the stop light switch assembly connector.
(e) Reconnect the ECM connector.
Result |
Proceed to |
---|---|
NG |
A |
OK (for 1AR-FE) |
B |
OK (for 2GR-FE) |
C |
A | ![]() |
REPAIR OR REPLACE HARNESS OR CONNECTOR (ECM - STOP LIGHT SWITCH ASSEMBLY) |
B | ![]() |
REPLACE ECM |
C | ![]() |
REPLACE ECM |
Control Module Communication Bus OFF (U0073/86,U0100/85,U0129/83)
DESCRIPTION
The AWD control ECU inputs the signals sent from the ECM and skid control
ECU via the CAN communication system.
When DTCs indicating a CAN communication system malfunction are output,
repair the CAN communication system before r ...
Registering ID codes
The tire pressure warning valve and transmitter is equipped with a unique ID
code. When replacing a tire pressure warning valve and transmitter, it is necessary
to register the ID code of tire pressure warning valve and transmitter. Have the
ID code regi ...
IG Signal Circuit
DESCRIPTION
This circuit detects the ignition switch ON or off condition, and sends it to
the main body ECU (driver side junction block assembly).
WIRING DIAGRAM
CAUTION / NOTICE / HINT
NOTICE:
Inspect the fuses for circuits related to this system b ...