Engine Control - SFI System

2UR-GSE ENGINE CONTROL: SFI SYSTEM: P0724: Brake Switch "B" Circuit High

DTC 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 1.86 mph [3 km/h]) and go (18.65 mph [30 km/h] or more) 5 times during 2 driving cycles, in order to detect a malfunction.

MONITOR STRATEGY





TYPICAL ENABLING CONDITIONS

The stop light switch remains ON during GO and STOP 5 times.

GO and STOP are defined as follows;





TYPICAL MALFUNCTION THRESHOLDS





WIRING DIAGRAM





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.

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 -- INSPECT STOP LIGHT SWITCH ASSEMBLY
OK -- CHECK FOR INTERMITTENT PROBLEMS
2. INSPECT STOP LIGHT SWITCH ASSEMBLY P0504

NG -- REPLACE STOP LIGHT SWITCH ASSEMBLY
OK -- Continue to next step.
3. 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 Short):





(d) Reconnect the stop light switch connector and ECM connector.
NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR (STOP LIGHT SWITCH - ECM)
OK -- REPLACE ECM