AA80E Automatic Transmission

AA80E AUTOMATIC TRANSMISSION: AUTOMATIC TRANSMISSION SYSTEM: 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 the lock-up condition when the brakes are suddenly applied.

When the brake pedal is depressed, this switch sends a signal to the TCM. Then the TCM 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 GO and STOP driving, the TCM interprets this as a fault in the stop light switch. Then the MIL illuminates and the TCM stores the DTC. The vehicle must GO (30 km/h (18.63 mph) or more) and STOP (less than 3 km/h (1.86 mph)) 5 times for 2 driving cycles in order for the DTC to be output.

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

NOTICE:
Perform the universal trip to clear permanent DTCs DTC Check / Clear.

HINT
Using the 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.

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

- Warm up the engine.

- Turn the engine switch off.

- Connect the Techstream to the DLC3.

- Turn the engine switch on (IG).

- Turn the Techstream on.

- Enter the following menus: Powertrain / ECT / Data List.

- According to the display on the Techstream, read the Data List.

TCM:





PROCEDURE

1. INSPECT STOP LIGHT SWITCH





(a) Remove the stop light switch.

(b) Measure the resistance of the stop light switch.

Standard resistance:





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

2. CHECK STOP LIGHT SWITCH (POWER SOURCE)

(a) Disconnect the A35 stop light switch connector.





(b) Measure the voltage of the wire harness side connector.

Standard voltage:





NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR (STOP LIGHT SWITCH - BATTERY)
OK -- Continue to next step.

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

(a) Connect the stop light switch connector.





(b) Disconnect the TCM 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 -- Continue to next step.

4. REPLACE TCM

(a) Replace the TCM Service and Repair.

NEXT -- PERFORM A/T CODE REGISTRATION Registration