Engine Control System

DTC Detecting Condition:

CIRCUIT DESCRIPTION
This signal is used to detect when the brakes have been applied.The STP signal voltage is the same as the voltage supplied to the stop lights.
The STP signal is used mainly to control the fuel cut-off engine speed.(The fuel cut-off engine speed is reduced slightly when the vehicle is braking.)

Wiring Diagram:

Step 1:

Steps 2 - 3:

INSPECTION PROCEDURE

HINT: Read freeze frame data using LEXUS hand-held tester or OBD II scan tool. 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

LEXUS hand-held tester only:
By putting the vehicle's ECM in the check mode, 1 trip detection logic is possible instead of 2 trip detection logic and sensitivity to detect open circuits is increased. This makes it easier to detect intermittent problems.
1. Clear the DTCs (See step 2).
2. Set the check mode (See step 3).
3. Perform a simulation test.
4. Check the connector and terminal.
5. Handle the connector.