DTC P0571: Stop Light Switch Circuit Malfunction [08/2015 - 08/2019]: Procedure
WARNING: This page is about a different car, the 2019 Toyota 4Runner, 2018 Toyota 4Runner, 2017 Toyota 4Runner, and 2016 Toyota 4Runner. However, it is still accessible from the selected car via links, so may be relevant.
- CHECK HARNESS AND CONNECTOR (STOP LIGHT SWITCH ASSEMBLY - BATTERY)
- Disconnect the A47 stop light switch assembly connector.
- Measure the voltage according to the value(s) in the table below.
Standard Voltage
Tester Connection Switch Condition Specified Condition A47-6 (B) - Body ground Ignition switch ON 11 to 14 V Ignition switch off Below 1 V A47-7 (B) - Body ground Always 11 to 14 V TEXT IN ILLUSTRATION*a Front view of wire harness connector
(to Stop Light Switch Assembly) - Measure the resistance according to the value(s) in the table below.
Standard Resistance
Tester Connection Switch Condition Specified Condition A47-2 (GND) - Body ground Always Below 1 Ω
Result:
NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
Result:
OK
See step 2
- Disconnect the A47 stop light switch assembly connector.
- INSPECT STOP LIGHT SWITCH ASSEMBLY
- Inspect the stop light switch assembly (Refer to ON-VEHICLE INSPECTION [08/2015 - 08/2019] ).
Result:
NG
REPLACE STOP LIGHT SWITCH ASSEMBLY
(Refer to REMOVAL [08/2015 - ] )
Result:
OK
See step 3
- CHECK HARNESS AND CONNECTOR (STOP LIGHT SWITCH ASSEMBLY - ECM)
- Disconnect the A47 stop light switch assembly connector.
- Disconnect the F50 and F51 ECM connectors.
- Measure the resistance according to the value(s) in the table below.
Standard Resistance
Tester Connection Condition Specified Condition A47-3 (L) - F50-18 (STP) Always Below 1 Ω A47-5 (L) - F51-8 (ST1-) A47-3 (L) - Body ground Always 10 kΩ or higher A47-5 (L) - Body ground
Result:
OK
REPLACE ECM
(Refer to REMOVAL [08/2015 - ] )
Result:
NG
REPAIR OR REPLACE HARNESS OR CONNECTOR