P0724

1NR-FE ENGINE CONTROL: SFI SYSTEM: P0724: Brake Switch "B" Circuit High
P0724 - Brake Switch "B" Circuit High

DESCRIPTION

The stop light switch is part of 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. This DTC indicates that the stop light switch remains on. When the stop light switch remains on during GO and STOP driving, the ECM interprets this as a fault in the stop light switch. Then the MIL illuminates and the ECM stores the DTC.

MONITOR DESCRIPTION

This DTC indicates that the stop light switch remains on. When the stop light switch remains on during "STOP and GO" driving, the ECM interprets this as a fault in the stop light switch. The ECM turns on MIL and stores the DTC. The vehicle must STOP (less than 3 km/h [1.86 mph]) and GO (30 km/h [18.65 mph] or more) 5 times during 2 driving cycles, in order to detect a malfunction.

MONITOR STRATEGY

TYPICAL ENABLING CONDITIONS

TYPICAL MALFUNCTION THRESHOLDS

CONFIRMATION DRIVING PATTERN

1. Connect the Techstream to the DLC3.

2. Turn the ignition switch to ON and turn the Techstream on.

3. Clear DTCs (even if no DTCs are stored, perform the clear DTC procedure).

4. Turn the ignition switch off and wait for at least 30 seconds.

5. Turn the ignition switch to ON and turn the Techstream on [A].

6. Wait 5 seconds after clearing DTCs.

7. Enter the following menus: Powertrain / Engine and ECT / Trouble Codes [B].

8. Read pending DTCs.

HINT
- If a pending DTC is output, the system is malfunctioning.
- If a pending DTC is not output, perform the following procedure.

9. Enter the following menus: Powertrain / Engine and ECT / Utility / All Readiness.

10. Input the DTC: P0724.

11. Check the DTC judgment result.

HINT
- If the judgment result shows NORMAL, the system is normal.
- If the judgment result shows ABNORMAL, the system has a malfunction.
- If the judgment result shows INCOMPLETE or N/A, perform steps [C] through [E].

12. Start the engine [C].

13. Accelerate the vehicle to 30 km/h (18.65 mph) or more, depress the brake pedal and decelerate the vehicle to 3 km/h (1.86 mph) or less [D]. Repeat step [D] 5 times.

CAUTION:
When performing the confirmation driving pattern, obey all speed limits and traffic laws.

14. Check the DTC judgment result [E].

15. If no pending DTC is output, perform a universal trip and check for permanent DTCs Reading and Clearing Diagnostic Trouble Codes.

HINT
- If a permanent DTC is output, the system is malfunctioning.
- If no permanent DTC is output, the system is normal.

WIRING DIAGRAM

Refer to DTC P0504 P0504.

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 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.
- Using the Techstream, the Data List item "Stop Light Switch" and "ST1" can be read P0504.

PROCEDURE

1. READ VALUE USING TECHSTREAM (STOP LIGHT SWITCH)

(a) Connect the Techstream to the DLC3.

(b) Turn the ignition switch to ON.

(c) Turn the Techstream on.

(d) Enter the following menus: Powertrain / Engine and ECT / Data List / Stop Light Switch.

(e) Read the values displayed on the Techstream.

OK:

NG -- CHECK STOP LIGHT SWITCH ASSEMBLY INSTALLATION

OK -- CHECK FOR INTERMITTENT PROBLEMS Check for Intermittent Problems

2. CHECK STOP LIGHT SWITCH ASSEMBLY INSTALLATION

(a) Check the stop light switch installation Adjustments.

OK:

Stop light switch is installed correctly.

NG -- SECURELY REINSTALL STOP LIGHT SWITCH ASSEMBLY Installation
OK -- Continue to next step.

3. INSPECT STOP LIGHT SWITCH ASSEMBLY

(a) Inspect the stop light switch assembly Testing and Inspection.

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

4. CHECK HARNESS AND CONNECTOR (STOP LIGHT SWITCH ASSEMBLY - ECM)

(a) Disconnect the ECM connector.

(b) Turn the ignition switch to ON.

Text in Illustration

NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR

OK -- REPLACE ECM Removal