Dtc P0504 Brake Switch A / B Correlation
Engine. Toyota Rav4. Aca30, 33, 38 Gsa33 Zsa30, 35
DESCRIPTION
WIRING DIAGRAM
INSPECTION PROCEDURE
CHECK STOP LIGHT SWITCH ASSEMBLY (TERMINAL VOLTAGE)
INSPECT STOP LIGHT SWITCH ASSEMBLY
CHECK ECM (STP AND ST1- VOLTAGE)
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 signals which indicate the brake pedal is being depressed and released are detected simultaneously, the ECM interprets this as a malfunction in the stop light switch and stores the DTC.- HINT:
- The normal conditions are shown in the table below. The signals can be read using the intelligent tester.
Signal
| Brake Pedal Released
| In Transition
| Brake Pedal Depressed
|
STP
| OFF
| ON
| ON
|
ST1-
| ON
| ON
| OFF
|
DTC No.
| DTC Detection Condition
| Trouble Area
|
P0504
| Conditions (a), (b) and (c) continue for 0.5 seconds or more (1 trip detection logic):
(a) The ignition switch is turned to ON.
(b) The brake pedal is released.
(c) The STP signal is off when the ST1- signal is off.
| - Open or short in stop light switch signal circuit
- Stop light switch
- STOP fuse
- IGN fuse
- ECM
|
WIRING DIAGRAM
INSPECTION PROCEDURE
- NOTICE:
- Inspect the fuses for circuits related to this system before performing the following inspection procedure.
- HINT:
- Read freeze frame data using the intelligent tester. The ECM records vehicle and driving condition information as freeze frame data the moment a DTC is stored. When troubleshooting, freeze frame data can help determine if the vehicle was moving or stationary, if the engine was warmed up or not, if the air fuel ratio was lean or rich, and other data from the time the malfunction occurred.
- STP signal condition can be checked using the intelligent tester.
- Connect the intelligent tester to the DLC3.
- Turn the ignition switch to ON and turn the tester on.
- Enter the following menus: Powertrain / Engine and ECT / Data List / Stop Light Switch.
- Check the STP signal when the brake pedal is depressed and released.
Brake Pedal Operation
| Specified Condition
|
Depressed
| STP signal ON
|
Released
| STP signal OFF
|
| 1.CHECK STOP LIGHT SWITCH ASSEMBLY (TERMINAL VOLTAGE) |
Disconnect the 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
|
A66-2 - Body ground
| Always
| 11 to 14 V
|
A66-4 - Body ground
| Ignition switch ON
| 11 to 14 V
|
Text in Illustration*1
| Front view of wire harness connector
(to Stop Light Switch)
|
Reconnect the stop light switch assembly connector.
| | REPAIR OR REPLACE HARNESS OR CONNECTOR (STOP LIGHT SWITCH ASSEMBLY - IG2 RELAY, BATTERY) |
|
|
| 2.INSPECT STOP LIGHT SWITCH ASSEMBLY |
Remove the stop light switch assembly.
Measure the resistance according to the value(s) in the table below.
- Standard Resistance:
Tester Connection
| Switch Condition
| Specified Condition
|
1 - 2
| Switch pin released
| Below 1 Ω
|
Switch pin pushed
| 10 kΩ or higher
|
3 - 4
| Switch pin released
| 10 kΩ or higher
|
Switch pin pushed
| Below 1 Ω
|
Reinstall the stop light switch assembly.
| | REPLACE STOP LIGHT SWITCH ASSEMBLY |
|
|
| 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:
Tester Connection
| Brake Pedal Operation
| Specified Condition
|
A12-35 (ST1-) - Body ground
| Brake pedal released
| 11 to 14 V
|
Brake pedal depressed
| Below 1.5 V
|
A12-36 (STP) - Body ground
| Brake pedal released
| Below 1.5 V
|
Brake pedal depressed
| 11 to 14 V
|
Reconnect the ECM connector.
| | REPAIR OR REPLACE HARNESS OR CONNECTOR (STOP LIGHT SWITCH - ECM) |
|
|
