DTC P0504: Brake Switch "A" / "B" Correlation [08/2015 - 08/2017]: Procedure
WARNING: This page is about a different car, the 2018 Toyota Sequoia, 2017 Toyota Sequoia, and 2016 Toyota Sequoia. However, it is still accessible from the selected car via links, so may be relevant.
- CHECK STOP LIGHT SWITCH ASSEMBLY (B+ VOLTAGE)
- Disconnect the A4 stop light switch connector.
- Measure the voltage according to the value(s) in the table below.
Standard voltage
Tester Connection Switch Condition Specified Condition A4-2 - Body ground Always 11 to 14 V A4-4 - Body ground Ignition switch ON 11 to 14 V
Result:
NG
See step 4
Result:
OK
See step 2
- INSPECT STOP LIGHT SWITCH ASSEMBLY
- Remove the stop light switch (Refer to REMOVAL [08/2015 - ] ).
- Measure the resistance according to the value(s) in the table below.
Standard resistance
Tester Connection Switch Condition Specified Condition 1 - 2 Pin not pushed Below 1 Ω Pin pushed 10 kΩ or higher 3 - 4 Pin not pushed 10 kΩ or higher Pin pushed Below 1 Ω
Result:
NG
REPLACE STOP LIGHT SWITCH ASSEMBLY
(Refer to REMOVAL [08/2015 - ] )
Result:
OK
See step 3
- CHECK ECM (STP AND ST1 - VOLTAGE)
- Disconnect the A27 ECM connector.
- Turn the ignition switch to ON.
- Measure the voltage according to the value(s) in the table below.
Standard voltage
Tester Connection Condition Specified Condition A27-35 (ST1-) - Body ground Brake pedal released 11 to 14 V Brake pedal depressed 0 to 3 V A27-26 (STP) - Body ground Brake pedal released 0 to 3 V Brake pedal depressed 11 to 14 V
Result:
OK
REPLACE ECM
(Refer to REMOVAL [08/2015 - 08/2018] )
Result:
NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
- INSPECT FUSE (STOP AND IGN)
- Remove the STOP and IGN fuses from the engine room relay block.
- Measure the resistance according to the value(s) in the table below.
Standard resistance
Tester Connection Condition Specified Condition STOP fuse Always Below 1 Ω IGN fuse Always Below 1 Ω
Result:
OK
REPAIR OR REPLACE HARNESS OR CONNECTOR (ECM - STOP LIGHT SWITCH)
Result:
NG
CHECK FOR SHORTS IN ALL HARNESSES AND CONNECTORS CONNECTED TO FUSE AND REPLACE FUSE