P0504

2GR-FE ENGINE CONTROL: SFI SYSTEM: P0504: Brake Switch "A" / "B" Correlation

DTC P0504 - Brake Switch "A" / "B" Correlation

DESCRIPTION

The stop light switch assembly is a duplex system that transmits 2 signals: STP and ST1-. These 2 signals are used by the ECM to monitor whether or not the brake system is working properly. If both signals, which indicate the brake pedal is being depressed or released, are detected simultaneously, the ECM interprets this as a malfunction in the stop light switch assembly and sets the DTC.
HINT: The normal conditions are as shown in the table below. The signals can be read using the Techstream.









CONFIRMATION DRIVING PATTERN





1. Connect the Techstream to the DLC3.
2. Turn the ignition switch to ON and turn the Techstream on [A].
3. Clear the DTCs (even if no DTCs are stored, perform the Clear DTC procedure) DTC Check / Clear.
4. Depress and release the brake pedal [B].
5. Enter the following menus: Powertrain / Engine / Utility / All Readiness.
6. Input the DTC: P0504.
7. Check the DTC judgment result[C].





HINT: If the judgment result shows ABNORMAL, the system has a malfunction.

8. If the test result is UNKNOWN, enter the following menus: Powertrain / Engine / Trouble Codes / Pending.
9. Read Pending DTCs.
HINT: If a pending DTC is output, the system is malfunctioning.

10. If the test result is INCOMPLETE or UNKNOWN and no pending DTC is output, perform a universal trip and check for permanent DTCs DTC Check / Clear.
HINT:
- If a permanent DTC is output, the system is malfunctioning.
- If no permanent DTC is output, the system is normal.

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 Techstream. The ECM records vehicle and driving condition information as freeze frame data the moment a DTC is stored. When troubleshooting, freeze frame data can be helpful in determining whether the vehicle was running or stopped, whether the engine was warmed up or not, whether the air fuel ratio was lean or rich, as well as other data recorded at the time of a malfunction.
- STP signal conditions can be checked using the Techstream.
1. Connect the Techstream to the DLC3.
2. Turn the ignition switch to ON.
3. Turn the Techstream on.
4. Enter the following menus: Powertrain / Engine / Data List / Stop Light Switch.
5. Check the STP signal when the brake pedal is depressed and released.





PROCEDURE

1. CHECK STOP LIGHT SWITCH ASSEMBLY (TERMINAL VOLTAGE)




(a) Disconnect the stop light switch assembly connector.
(b) Measure the voltage according to the value(s) in the table below.
Standard Voltage:





Text in Illustration





(c) Reconnect the stop light switch assembly connector.

NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR (STOP LIGHT SWITCH ASSEMBLY - BATTERY)
OK -- Continue to next step.

2. CHECK STOP LIGHT SWITCH ASSEMBLY (TERMINAL VOLTAGE)




(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:





Text in Illustration





(d) Reconnect the stop light switch assembly connector.

NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR (STOP LIGHT SWITCH ASSEMBLY - IG2 RELAY)
OK -- Continue to next step.

3. INSPECT STOP LIGHT SWITCH ASSEMBLY




(a) Remove the stop light switch assembly.
(b) Measure the resistance according to the value(s) in the table below.
Standard Resistance:





(c) Reinstall the stop light switch assembly.

NG -- REPLACE STOP LIGHT SWITCH ASSEMBLY
OK -- Continue to next step.

4. CHECK ECM (STP AND ST1 - VOLTAGE)
(a) Disconnect the ECM connector.




(b) Turn the ignition switch to ON.
(c) Measure the voltage according to the value(s) in the table below.
Standard Voltage:





(d) Reconnect the ECM connector.

NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR (STOP LIGHT SWITCH ASSEMBLY - ECM)
OK -- REPLACE ECM