A760H Automatic Transmission: Electronic Controlled Automatic Transmission System

A760H AUTOMATIC TRANSMISSION: ELECTRONIC CONTROLLED AUTOMATIC TRANSMISSION 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 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 10 times.

GO and STOP is defined as follows;






TYPICAL MALFUNCTION THRESHOLDS





WIRING DIAGRAM





INSPECTION PROCEDURE

PROCEDURE

1. READ VALUE USING DATA LIST (STP SIGNAL)
HINT: According to the Data List displayed by the Techstream, you can read the value of the switch, sensor, actuator and so on without parts removal. Reading the Data List as the first step of troubleshooting is one method to shorten labor time.
(a) Warm up the engine.
(b) Turn the engine switch off.
(c) Connect the Techstream to the DLC3.
(d) Turn the engine switch on (IG).
(e) Turn on the tester.
(f) Select the item "Powertrain / Engine and ECT / Data List".
(g) According to the display on the tester, read the "Data List".
Standard:





NOTE:
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.
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.
Voltage:






NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- REPLACE ECM