DESCRIPTION
WIRING DIAGRAM
INSPECTION PROCEDURE
CHECK STOP LIGHT SWITCH ASSEMBLY (TERMINAL B VOLTAGE)
INSPECT STOP LIGHT SWITCH ASSEMBLY
CHECK ECM (STP AND ST1- VOLTAGE)
INSPECT FUSE (STOP, IGN)
REPLACE STOP LIGHT SWITCH ASSEMBLY
REPLACE ECM
REPAIR OR REPLACE HARNESS OR CONNECTOR
CHECK FOR SHORTS IN ALL HARNESSES AND CONNECTORS CONNECTED TO FUSE AND REPLACE FUSE
CONFIRM WHETHER MALFUNCTION HAS BEEN SUCCESSFULLY REPAIRED
DTC P0504 Brake Switch "A" / "B" Correlation
DESCRIPTION
The stop light switch is a duplex system that transmits two signals: STP and ST1-. These two signals are used by the ECM to monitor whether or not the brake system is working properly. If the signals, which indicate that the brake pedal is being depressed and released, are detected simultaneously, the ECM interprets this as a malfunction in the stop light switch and sets the DTC.
- The normal conditions are as shown in the table below.
| Signals | Brake Pedal Released | In Transition | Brake Pedal Depressed |
| STP | OFF | ON | ON |
| ST1- | ON | ON | OFF |
P0504| DTC Detection Drive Pattern | DTC Detection Condition | Trouble Area |
| Release and depress brake pedal with ignition switch ON | Conditions (a), (b) and (c) continue for 0.5 seconds or more (1 trip detection logic):
(a) Ignition switch is ON.
(b) Brake pedal is released.
(c) The STP signal is off when the ST1- signal is off, or the STP signal is on when the ST1- signal is on. | Open or short in stop light switch signal circuit
STOP fuse
IGN fuse
Stop light switch
ECM
|
Related Data List| DTC No. | Data List |
| P0504 | Stop Light Switch |
WIRING DIAGRAM
INSPECTION PROCEDURE
Read freeze frame data using the intelligent tester. Freeze frame data records the engine condition when malfunctions are detected. When troubleshooting, freeze frame data can help determine if the vehicle was moving or stationary, if the engine was warmed up or not, and other data from the time the malfunction occurred.
Stop light switch conditions can be checked using the intelligent tester.
Connect the intelligent tester to the DLC3.
Turn the ignition switch to ON.
Turn the tester on.
Enter the following menus: Powertrain / Engine / Data List / Stop Light Switch.
Check Stop Light Switch when the brake pedal is depressed and released.
| Brake Pedal Operation | Specified Condition |
| Depressed | ON |
| Released | OFF |
| 1.CHECK STOP LIGHT SWITCH ASSEMBLY (TERMINAL B VOLTAGE) |
Disconnect the stop light switch connector.
Measure the voltage according to the value(s) in the table below.
- Standard Voltage:
| Tester Connection | Condition | Specified Condition |
| A30-2 - Body ground | Always | 11 to 14 V |
| A30-4 - Body ground | Ignition switch ON | 11 to 14 V |
| 2.INSPECT STOP LIGHT SWITCH ASSEMBLY |
Remove the stop light switch.
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 |
| Switch pin pushed | 10 kΩ or higher |
| 3 - 4 | Switch pin not pushed | 10 kΩ or higher |
| Switch pin pushed | Below 1 Ω |
| 3.CHECK ECM (STP AND ST1- VOLTAGE) |
Disconnect the ECM connector.
Turn the ignition switch to ON.
Measure the voltage according to the value(s) in the table below.
- Standard Voltage:
for LHD| Tester Connection | Brake Pedal Condition | Specified Condition |
| A38-35 (ST1-) - Body ground | Released | 11 to 14 V |
| Depressed | 0 to 3 V |
| A38-36 (STP) - Body ground | Released | 0 to 3 V |
| Depressed | 11 to 14 V |
for RHD| Tester Connection | Brake Pedal Condition | Specified Condition |
| A52-35 (ST1-) - Body ground | Released | 11 to 14 V |
| Depressed | 0 to 3 V |
| A52-36 (STP) - Body ground | Released | 0 to 3 V |
| Depressed | 11 to 14 V |
| 4.INSPECT FUSE (STOP, 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 |
| 5.REPLACE STOP LIGHT SWITCH ASSEMBLY |
Replace the stop light switch assembly ().
| 7.REPAIR OR REPLACE HARNESS OR CONNECTOR |
| 8.CHECK FOR SHORTS IN ALL HARNESSES AND CONNECTORS CONNECTED TO FUSE AND REPLACE FUSE |
| 9.CONFIRM WHETHER MALFUNCTION HAS BEEN SUCCESSFULLY REPAIRED |
Connect the intelligent tester to the DLC3.
Turn the ignition switch off.
Turn the ignition switch to ON and turn the tester on.
Brake pedal released and depressed.
Enter the following menus: Powertrain / Engine / DTC.
Confirm that the DTC is not output again.
