Trouble Shooting

NOTE: Prior to trouble shooting, ensure no problems exist in multiplex communications. If problems exist, repair multiplex control system before trouble shooting. See MULTIPLEX CONTROL SYSTEMS - LS400 article.

NOTE: Check circuits and components in listed order. If circuits or components are okay, return to trouble shooting and identify next circuit to be checked.

NOTE: Perform power tilt steering column system self-diagnostics before performing trouble shooting. See DIAGNOSTIC PROCEDURE under SELF-DIAGNOSTIC SYSTEM.

SYMPTOM DIAGNOSIS

Problem

Inspect

Manual, Auto Away/Return & Memory Functions Do Not Operate, Stop Part Way Or Do Not Stop

Tilt & Telescopic

⁽¹⁾ Multiplex Communication System; ⁽²⁾ ECU Power Source Circuit; ⁽³⁾ Key Unlock Warning Switch; ⁽⁴⁾ Body Control ECU; ⁽²⁾ Actuator Power Source Circuit; ⁽²⁾ Sensor Power Source Circuit; ⁽²⁾ Tilt Motor Circuit; ⁽²⁾ Telescopic Motor Circuit; ⁽⁵⁾ Tilt & Telescopic ECU

Tilt Only

⁽¹⁾ Multiplex Communication System; ⁽²⁾ Sensor Power Source Circuit; ⁽²⁾ Tilt Motor Circuit; ⁽⁵⁾ Tilt & Telescopic ECU

Telescopic Only

⁽¹⁾ Multiplex Communication System; ⁽²⁾ Sensor Power Source Circuit; ⁽²⁾ Telescopic Motor Circuit; ⁽⁵⁾ Tilt & Telescopic ECU

Only Tilt & Telescopic Manual Switch Function Does Not Operate

Tilt & Telescopic

⁽¹⁾ Multiplex Communication System; ⁽²⁾ Tilt & Telescopic Manual Switch Circuit; ⁽⁵⁾ Tilt & Telescopic ECU

Tilt Only

⁽¹⁾ Multiplex Communication System; ⁽²⁾ Tilt & Telescopic Manual Switch Circuit; ⁽⁵⁾ Tilt & Telescopic ECU

Telescopic Only

⁽¹⁾ Multiplex Communication System; ⁽²⁾ Tilt & Telescopic Manual Switch Circuit; ⁽⁵⁾ Tilt & Telescopic ECU

Only Auto Away/Return Function Does Not Operate

Away & Return

Check Status Of Auto Away Function Using LEXUS Scan Tool; ⁽¹⁾ Multiplex Communication System; ⁽³⁾ Ignition Switch; ⁽³⁾ Key Unlock Warning Switch; ⁽⁵⁾ Tilt & Telescopic ECU

Away Only

⁽¹⁾ Multiplex Communication System; ⁽³⁾ Key Unlock Warning Switch Circuit; ⁽³⁾ Ignition Switch; ⁽⁵⁾ Tilt & Telescopic ECU

Return Only

⁽¹⁾ Multiplex Communication System; ⁽³⁾ Key Unlock Warning Switch; ⁽³⁾ Ignition Switch; ⁽⁵⁾ Tilt & Telescopic ECU

Only Memory Function Does Not Operate

⁽¹⁾ Multiplex Communication System; ⁽⁶⁾Driver Door ECU; ⁽⁷⁾ Power Seat ECU; ⁽⁵⁾ Tilt & Telescopic ECU

Mirror Function Does Not Operate

⁽¹⁾ Multiplex Communication System; ⁽³⁾ Mirror Select Switch Circuit; ⁽³⁾ Mirror Adjust Manual Switch Circuit; ⁽⁵⁾ Tilt & Telescopic ECU

Shoulder Belt Anchor Does Not Operate

⁽¹⁾ Multiplex Communication System; Driver Door ECU; ⁽³⁾ Shoulder Belt Anchor Motor Circuit; ⁽⁵⁾ Tilt & Telescopic ECU

⁽¹⁾	See MULTIPLEX CONTROL SYSTEMS - LS400 article.

⁽²⁾	Perform appropriate circuit test under CIRCUIT TESTS . If more than one circuit test is listed, perform tests in order listed.

⁽³⁾	See STEERING COLUMN SWITCHES article.

⁽⁴⁾	See BODY CONTROL SYSTEMS - LS400 article.

⁽⁵⁾	Perform TILT & TELESCOPIC ECU PIN VOLTAGE TESTS under COMPONENT TESTS. Repair or replace components as necessary.

⁽⁶⁾	See appropriate wiring diagram in POWER DOOR LOCKS, TRUNK LID & FUEL DOOR RELEASE article.

⁽⁷⁾	See appropriate wiring diagram in appropriate POWER SEATS article.