P0504

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 or released, are detected simultaneously, the ECM interprets this as a malfunction in the stop light switch and sets the DTC.

HINT
The normal 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

P0724

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 2 mph (3 km/h)) and go (19 mph (30 km/h) or more) 5 times for two driving cycles in order to detect a malfunction.

MONITOR STRATEGY





TYPICAL ENABLING CONDITIONS





TYPICAL MALFUNCTION THRESHOLDS





WIRING DIAGRAM









CONFIRMATION DRIVING PATTERN

P0724:





1. Connect the Techstream to the DLC3.

2. Turn the ignition 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 ignition switch off and wait for 30 seconds.

5. Turn the ignition switch on (IG) and turn the Techstream on [A].

6. Wait 5 seconds after clear the DTCs.

7. Enter the following menus: Powertrain / Engine and ECT / 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 and ECT / 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 and ECT / 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.

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.
* Stop light switch conditions can be checked using the Techstream.
(1) Connect the Techstream to the DLC3.
(2) Turn the ignition switch on (IG).
(3) Turn the Techstream on.
(4) Enter the following menus: Powertrain / Engine and ECT / Data List / Stop Light Switch and ST1.
(5) Check the Data List indication when the brake pedal is depressed and released.





PROCEDURE

1. CHECK OPERATION OF STOP LIGHT

(a) Check whether the stop lights turn on and off normally when the brake pedal is depressed and released.

OK:

Stop lights turn on when brake pedal is depressed.

NG -- GO TO LIGHTING SYSTEM (STOP LIGHT SYSTEM) Symptom Related Diagnostic Procedures
OK -- Continue to next step.

2. 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.

3. READ VALUE USING TECHSTREAM (STP SIGNAL AND ST1- VOLTAGE)

(a) Connect the Techstream to the DLC3.





(b) Turn the ignition switch on (IG) and turn the Techstream on.

(c) Select the following menu items: Powertrain / Engine and ECT / Data List / Stop Light Switch.

(d) Check the STP signal when the brake pedal is depressed and released.

Standard:





(e) Measure the voltage according to the value(s) in the table below.

Standard voltage:





Text in Illustration





NG -- CHECK HARNESS AND CONNECTOR (STOP LIGHT SWITCH - ECM)

OK -- CHECK FOR INTERMITTENT PROBLEMS Check for Intermittent Problems

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

(a) Disconnect the stop light switch connector.

(b) Disconnect the ECM connector.

(c) Measure the resistance according to the value(s) in the table below.

Standard resistance:

Check for open






(d) Reconnect the stop light switch connector.

(e) Reconnect the ECM connector.

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

OK -- REPLACE ECM Components