Brake Switch "B" Circuit High (P0724)

The purpose of this circuit is to prevent the engine from stalling when brakes are suddenly applied while driving in lock-up condition.

When the brake pedal is depressed, the stop light switch sends a signal to the ECM. Then the ECM cancels the operation of the lock-up clutch while braking is in progress.

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 [1,9 mph]) and go (30 km/h [18,6 mph] or more) 5 times during 2 driving cycles, in order to detect a malfunction.

1. 1
   Connect the Techstream to the DLC3.
2. 2
   Turn the ignition switch to ON and turn the Techstream on.
3. 3
   Clear the DTCs (even if no DTCs are stored, perform the clear DTC procedure) (See page ).
4. 4
   Turn the ignition switch off and wait for at least 30 seconds.
5. 5
   Turn the ignition switch to ON and turn the Techstream on [A].
6. 6
   Wait 5 seconds.
7. 7
   Enter the following menus: Powertrain / Engine / Trouble Codes [B].
8. 8
   Read the 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. 9
   Enter the following menus: Powertrain / Engine / Utility / All Readiness.
10. 10
    Input the DTC: P0724.
11. 11
    Check the DTC judgment result.

    Techstream Display	Description
    NORMAL	DTC judgment completed System normal
    ABNORMAL	DTC judgment completed System abnormal
    INCOMPLETE	DTC judgment not completed Perform driving pattern after confirming DTC enabling conditions
    N/A	Unable to perform DTC judgment Number of DTCs which do not fulfill DTC preconditions has reached ECU memory limit

    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. 12
    Start the engine [C].
13. 13
    Accelerate the vehicle to 30 km/h or more, depress the brake pedal and decelerate the vehicle to 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.

14. 14
    Check the DTC judgment result [E].
15. 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 (See page ).
    

    HINT:

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

Refer to DTC P0504 (See page ).

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.

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 / Data List / Stop Light Switch.

(e) Read the values displayed on the Techstream.

OK:

OK

CHECK FOR INTERMITTENT PROBLEMS

NG

1. INSPECT STOP LIGHT SWITCH ASSEMBLY

(a) Inspect the stop light switch assembly (See page ).

NG

REPLACE STOP LIGHT SWITCH ASSEMBLY

OK

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

(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:

OK

REPLACE ECM

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR