AUTOMATIC TRANSMISSION SYSTEM - Kick Down Switch Circuit

DESCRIPTION

The kick-down switch is turned ON when the accelerator pedal is fully depressed and a signal is sent to the ECM.

When the kick-down switch is turned ON, the ECM controls gear shifting according to the programmed shift diagrams.

If a short circuit develops in the kick-down switch, the ECM disregards the kick-down signals and controls shifting at the normal shift points.

Automatic Transmission System - Kick Down Switch Circuit. A960E AUTOMATIC TRANSMISSION. Lexus IS250 IS220d GSE20 ALE20

1.CHECK HARNESS AND CONNECTOR (KICK DOWN SWITCH - BODY GROUND)

Disconnect the kick-down switch connector.

Measure the resistance according to the value(s) in the table below.

REPAIR OR REPLACE HARNESS OR CONNECTOR

OK

2.INSPECT KICK DOWN SWITCH ASSEMBLY

Measure resistance according to the value(s) in the table below when kick-down switch is ON and OFF.

Resistance:
Switch Condition Tester Connection Specified Condition
Press continuously
(Kick-down switch is ON) 1 - 2 Below 1 Ω
Release
(Kick-down switch is OFF) ↑ 10 kΩ or higher

REPLACE KICK DOWN SWITCH ASSEMBLY

OK

3.CHECK HARNESS AND CONNECTOR (KICK DOWN SWITCH - ECM)

Connect the kick-down switch connector.

Disconnect the ECM connector.

Measure resistance according to the value(s) in the table below when accelerator pedal is fully depressed or not.

Resistance:
Switch Condition Tester Connection Specified Condition
Fully depressed
(Kick-down switch is ON) A5 - 26 (KD) - Body ground Below 1 Ω
Release
(Kick-down switch is OFF) ↑ 10 kΩ or higher

REPAIR OR REPLACE HARNESS OR CONNECTOR

PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE

LEXUS IS250, IS220d / GSE20 ALE20

Tester Connection	Specified Condition
1 - Body ground	Below 1 Ω

Switch Condition	Tester Connection	Specified Condition
Press continuously (Kick-down switch is ON)	1 - 2	Below 1 Ω
Release (Kick-down switch is OFF)	↑	10 kΩ or higher