SFI System
2GR-FE ENGINE CONTROL SYSTEM: SFI SYSTEM: P0504, P0724: Brake Switch "A" / "B" Correlation
P0724 - Brake Switch "B" Circuit High
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 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.
HINT
The normal signal conditions are as shown in the table below.
- [OFF] denotes ground potential.
- [ON] denotes battery potential (+B).
- On the Techstream, both the Data List items Stop Light Switch and ST1 are ON when the brake pedal is depressed because the ST1 indication characteristic is opposite to the Stop Light Switch indication.
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 and the MIL comes on and the ECM stores the DTC. The vehicle must stop (less than 1.86 mph (3 km/h)) and go (18.65 mph (30 km/h) or more) 5 times in two driving cycles in order to detect a malfunction.
MONITOR STRATEGY
TYPICAL ENABLING CONDITIONS
TYPICAL MALFUNCTION THRESHOLDS
CONFIRMATION DRIVING PATTERN
P0504:
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 30 seconds.
5. Turn the engine switch on (IG) and turn the Techstream on.
6. Depress and release the brake pedal.
7. Enter the following menus: Powertrain / Engine / Trouble Codes.
8. Read the DTC.
9. If a DTC is output, the system is malfunctioning.
HINT
If a DTC is not output, perform the following procedure.
10. Enter the following menus: Powertrain / Engine / Utility / All Readiness.
11. Input the DTC: P0504.
12. 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.
13. If the test result is INCOMPLETE or N/A and no 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.
P0724:
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 30 seconds.
5. Turn the engine switch on (IG) and turn the Techstream on [A].
6. Wait 5 seconds after clear the DTCs.
7. Enter the following menus: Powertrain / Engine / Trouble Codes / Pending.
8. Read the pending DTC [B].
9. If a pending DTC is output, the system is malfunctioning.
HINT
If a pending DTC is not output, perform the following procedure.
10. Enter the following menus: Powertrain / Engine / Utility / All Readiness.
11. Input the DTC: P0724.
12. 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].
13. Start the engine [C].
14. Accelerate the vehicle to 19 mph (30 km/h) or more, depress the brake pedal and decelerate the vehicle to 1.8 mph (3 km/h) or less [D]. Repeat step [D] 5 times.
CAUTION:
When performing the confirmation driving pattern, obey all speed limits and traffic laws.
15. Enter the following menus: Powertrain / Engine / Utility / All Readiness.
16. Check the DTC judgment result [E].
HINT
- If the judgment result shows ABNORMAL, the system has a malfunction.
- If the judgment result shows NORMAL, the system is normal.
17. 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
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.
- Stop light switch assembly conditions can be checked using the Techstream.
(1) Connect the Techstream to the DLC3.
(2) Turn the engine switch on (IG).
(3) Turn the Techstream on.
(4) Enter the following menus: Powertrain / Engine / Data List / Stop Light Switch and ST1.
(5) Check the Data List indication when the brake pedal is depressed and released.
PROCEDURE
1. READ VALUE USING TECHSTREAM (STP SIGNAL AND ST1- SIGNAL)
(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) Check the STP signal when the brake pedal is depressed and released.
OK:
(e) Enter the following menus: Powertrain / Engine / Data List / ST1.
(f) Check the ST1 signal when the brake pedal is depressed and released.
OK:
OK -- CHECK FOR INTERMITTENT PROBLEMS Check for Intermittent Problems
NG -- Continue to next step.
2. INSPECT STOP LIGHT SWITCH ASSEMBLY
(a) Inspect the stop light switch assembly Inspection.
NG -- REPLACE STOP LIGHT SWITCH ASSEMBLY Removal
OK -- Continue to next step.
3. CHECK ECM (STP, ST1- VOLTAGE)
(a) Disconnect the A10 ECM connector.
(b) Measure the voltage according to the value(s) in the table below.
Standard voltage:
(c) Turn the engine switch on (IG).
(d) Measure the voltage according to the value(s) in the table below.
Standard voltage:
NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- REPLACE ECM Removal