SFI System
2UR-GSE ENGINE CONTROL: SFI SYSTEM: P0724: Brake Switch "B" Circuit High
P0724 - Brake Switch "B" Circuit High
DESCRIPTION
The purpose of this circuit is to prevent the engine from stalling, while driving in lock-up condition, when brakes are suddenly applied.
When the brake pedal is depressed, this switch sends a signal to the ECM. Then the ECM cancels the operation of the lock-up clutch while braking is in progress.
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 malfunction in the stop light switch and the MIL comes on and the ECM 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 engine switch on (IG) and turn the Techstream on.
3. Clear the DTCs (even if no DTCs are stored, perform the clear DTC procedure) Reading and Clearing Diagnostic Trouble Codes.
4. Turn the engine switch off and wait for at least 30 seconds.
5. Turn the engine switch on (IG) and turn the Techstream on [A].
6. Wait 5 seconds.
7. Enter the following menus: Powertrain / Engine / Trouble Codes.
8. Read the pending DTC [B].
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 / Utility / All Readiness.
10. Input the DTC: P0724.
11. Check the DTC judgment result.
HINT
- If the judgment result shows ABNORMAL, the system has a malfunction.
- If the judgment result shows NORMAL, the system is normal.
- 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 (18.6 mph) or more, depress the brake pedal and decelerate the vehicle to 3 km/h (1.8 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 the test result is INCOMPLETE or N/A and 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
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.
- Using the Techstream, the Data List item "Stop Light Switch" and "ST1" can be read Data List / Active List.
PROCEDURE
1. READ VALUE USING TECHSTREAM (STOP LIGHT SWITCH)
(a) Connect the Techstream to the DLC3.
(b) Turn the engine switch on (IG) and turn the Techstream on.
(c) Enter the following menus: Powertrain / Engine / Data List / Stop Light Switch.
(d) 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 assembly installation Adjustments.
OK:
Stop light switch assembly is installed correctly.
NG -- SECURELY REINSTALL STOP LIGHT SWITCH ASSEMBLY
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 - ECM)
(a) Measure the voltage according to the value(s) in the table below.
Standard Voltage:
NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR (STOP LIGHT SWITCH - ECM)
OK -- REPLACE ECM Removal