Transmission Control System

DTC P0724 Brake Switch "B" Circuit High

CIRCUIT DESCRIPTION

DTC Detecting Condition:

This circuit prevents the engine from stalling when brakes are suddenly applied during driving under lock-up condition.

When the brake pedal is operated, this switch sends a signal to the ECM. Then the ECM cancels operation of the lock-up clutch while braking is in progress.

MONITOR DESCRIPTION

Monitor Strategy:

Typical Enabling Conditions:

Typical Malfunction Thresholds:

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 turns on. The vehicle must stop and go (3 km/h (2 mph) to 30 km/h (19 mph)) ten times for two driving cycles in order to detect malfunction.

Wiring Diagram:

Step 1 - 2:

Step 3:

INSPECTION PROCEDURE

HINT: Read freeze frame data using OBD II scan tool or hand-held tester. Because freeze frame records the engine conditions when the malfunction is detected. When troubleshooting, it is useful for determining whether the vehicle was running or stopped, the engine was warmed up or not, the air fuel ratio was lean or rich, etc. at the time of the malfunction.

CHECK FOR INTERMITTENT PROBLEMS

Hand-held tester only:
Inspect the vehicle's ECM using check mode. Intermittent problems are easier to detect when the ECM is in check mode with hand-held tester. In check mode, the ECM uses 1 trip detection logic, which has a higher sensitivity to malfunctions than normal mode (default), which uses 2 trip detection logic.

a. Clear the DTCs.
b. Set the check mode.
c. Perform a simulation test.
d. Check the connector and terminal.
e. Wiggle the harness and connector.