Automatic Transaxle System

U241E AUTOMATIC TRANSAXLE: AUTOMATIC TRANSAXLE 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 signals 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) 5 times for two driving cycles in order to detect a malfunction.

MONITOR STRATEGY





TYPICAL ENABLING CONDITIONS





TYPICAL MALFUNCTION THRESHOLDS





WIRING DIAGRAM





INSPECTION PROCEDURE

PROCEDURE

1. READ VALUE USING DATA LIST
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.
(a) Warm up the engine.
(b) Turn the ignition switch off.
(c) Connect the Techstream to the DLC3.
(d) Turn the ignition switch to ON.
(e) Turn on the Techstream.
(f) Select the item "Powertrain / Engine and ECT / Data List".
(g) According to the display on the tester, read the "Data List".





NOTICE: In the table below, the value listed under "Normal Condition" are reference values. Do not depend solely on these reference values when deciding whether apart 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