A760H Automatic Transmission

A760H AUTOMATIC TRANSMISSION: AUTOMATIC TRANSMISSION SYSTEM (for 4GR-FSE): 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 fault 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 (2 mph)) and go (30 km/h (19 mph) or more) ten times for two 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 is defined as follows;





TYPICAL MALFUNCTION THRESHOLDS





WIRING DIAGRAM

P0504.

INSPECTION PROCEDURE

NOTICE:
Perform the universal trip to clear permanent DTCs Reading and Clearing Diagnostic Trouble Codes.

PROCEDURE

1. READ VALUE USING DATA LIST (STP SIGNAL)

HINT
Using Techstream to read the Data List allows the values or states of switches, sensors, actuators and other items to be read without removing any parts. This non-intrusive inspection can be very useful because intermittent conditions or signals may be discovered before parts or wiring is disturbed. Reading the Data List information early in troubleshooting is one way to save diagnostic time.

(a) Turn the engine switch off.

(b) Connect the Techstream to the DLC3.

(c) Turn the engine switch on (IG) position.

(d) Turn the Techstream on.

(e) Select the item "Powertrain / ECT / Data List".

(f) According to the display on the tester, read the "Data List".

Standard:





NOTICE:
In the table above, the conditions listed under "Normal Condition" are reference conditions. Do not depend solely on these reference conditions when deciding whether a part is faulty or not.

OK -- CHECK HARNESS AND CONNECTOR (STOP LIGHT SWITCH ASSEMBLY - ECM)
NG -- Continue to next step.

2. INSPECT STOP LIGHT SWITCH ASSEMBLY

(a) Remove the stop light switch assembly.





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

Standard resistance:





NG -- REPLACE STOP LIGHT SWITCH ASSEMBLY
OK -- Continue to next step.

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

(a) Install the stop light switch assembly.





(b) Disconnect the ECM connector.

(c) Measure the voltage according to the value(s) in the table below when the brake pedal is depressed and released.

Standard voltage:





NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR

OK -- REPLACE ECM