Inspection Procedure

WARNING: This page is about a different car, the 2003 Lexus LS 430. However, it is still accessible from the selected car via links, so may be relevant.

HINT:

In case of using the LEXUS hand-held tester, start the inspection from step 1 and in case of not using the LEXUS hand-held tester, start from step 2.

Check stop light switch using LEXUS hand-held tester.

PREPARATION:

Connect the LEXUS hand-held tester to the DLC3.

CHECK:

Check the stop light switch using DATA LIST.

OK:

CONDITION

Condition	Stop light switch 1 (Sub CPU)	Stop light switch 2 (Sub CPU)	Stop light switch 2 (Main CPU)
Depressed	ON	ON	ON
Released	OFF	OFF	OFF

HINT:

Stop light SW1 has a function to disconnect the connection (OFF) when the pedal is depressed, however, ECM controls by the logic reverse, so with the LEXUS hand-held tester, it displays ON.
Stop light SW 1 indicates the input of ST1-terminal and Stop light SW 2 indicates the input of STP terminal.

OK : Proceed to next circuit inspection shown on problem symptom table (See PROBLEM SYMPTOMS TABLE ).
NG : Go to next step.

Check stop light switch (See INSPECTION ).
1. NG : Replace stop light switch.
2. OK : Go to next step.
Check wire harness and connector between terminal STP of ECM and stop light switch, and terminal ST1-of ECM and stop light switch (See HOW TO USE THE DIAGNOSTIC CHART AND INSPECTION PROCEDURE ).
1. NG : Repair or replace wire harness or connector.
2. OK : Check and replace ECM (See HOW TO USE THE DIAGNOSTIC CHART AND INSPECTION PROCEDURE ).