Trouble Shooting

NOTE: This is the flowchart when detecting PRESENT CODE. If recording PAST CODE, perform step 3 and check wiring connecting each part or connection failure of the connectors. For code details, see PRESENT CODE & PAST CODE of RETRIEVING DIAGNOSTIC CODES under SELF-DIAGNOSTIC SYSTEM.

Trouble shooting of a multiplex communication system complaint begins with verification of the customer problem. If problem occurs, go to step 3. If problem does not occur, go to next step.
If problem does not occur, review conditions under which problem occurred for customer and try to duplicate those conditions. For example, if the problem occurs on rainy days or during high humidity conditions, sprinkle water onto vehicle and see if malfunction occurs. DO NOT sprinkle water directly into engine compartment or onto electronic components. Visually inspect for signs of mechanical and electrical damage. Inspect for blown fuses and damaged relays. Inspect for loose or corroded connections, damaged wiring harnesses and/or switches. Check for a broken or partially broken wire inside insulation, which could cause system malfunction but prove good in a continuity/voltage check with system disconnected. Ensure any aftermarket electronic equipment is properly installed. If fault is found, repair as necessary. If problem still cannot be created, go to next step.
Perform pre-check. See PRE-CHECK under SELF-DIAGNOSTIC SYSTEM. If there is a normal code, go to the next step. If there is a malfunction code, perform a circuit inspection. See DIAGNOSTIC TESTS .

Determine problem symptom.

For air conditioning and other systems, see PROBLEM SYMPTOM INDEX (AIR CONDITIONING & OTHER SYSTEMS) table.
For door lock, window and security systems, see PROBLEM SYMPTOM INDEX (DOOR LOCK, WINDOW & SECURITY SYSTEMS) table.
For driver information system, see PROBLEM SYMPTOM INDEX (DRIVER INFORMATION SYSTEM) table.
For illumination and lighting systems, see PROBLEM SYMPTOM INDEX (ILLUMINATION & LIGHTING SYSTEMS) table.
For mirror, power seat and seat belt systems, see PROBLEM SYMPTOM INDEX (MIRROR, POWER SEAT & SEAT BELT SYSTEMS) table.

PROBLEM SYMPTOM INDEX (AIR CONDITIONING & OTHER SYSTEMS)

Symptom

Suspected Area ⁽¹⁾

Air Conditioning System

⁽²⁾

Rear Air Conditioning System

⁽²⁾⁽³⁾

Other Systems

Cellular Mobile Telephone

⁽⁴⁾

Cruise Control System

⁽⁵⁾

Fuel Lid Opener System

⁽⁶⁾⁽³⁾

Fuel Cut System When Colliding

⁽⁷⁾⁽⁸⁾

Headlight Cleaner System

⁽⁶⁾

Horn System

⁽⁹⁾

Adaptive Laser Cruise Control System

⁽⁵⁾⁽¹⁰⁾⁽¹¹⁾⁽¹²⁾⁽¹³⁾

Radio & Player System

⁽¹⁴⁾

Rear Sunshade System

⁽¹⁵⁾⁽³⁾

Rear Window Defogger System

⁽¹⁶⁾

Wiper & Washer System

⁽⁶⁾⁽⁹⁾⁽¹¹⁾⁽¹⁵⁾

Wiper & Washer System (Automatic Wiper System)

⁽¹⁵⁾⁽¹²⁾⁽¹¹⁾

LEXUS Link System

⁽¹⁷⁾

⁽¹⁾	Perform test procedures in order listed under suspected area.

⁽²⁾	Check the air conditioning system. See AUTOMATIC A/C-HEATER SYSTEMS - LS430 in HVAC.

⁽³⁾	Check the luggage room junction block ECU control system. See BODY CONTROL SYSTEMS article.

⁽⁴⁾	Check the LEXUS navigation system. Further diagnosis information is not available. Check the steering pad switch system. See appropriate STEERING COLUMN SWITCHES article.

⁽⁵⁾	Check the cruise control system. See appropriate CRUISE CONTROL article.

⁽⁶⁾	Check the driver side junction block (body No. 2) control system. For 2002, see BODY CONTROL SYSTEMS article. For 2003, see appropriate BODY CONTROL SYSTEMS article.

⁽⁷⁾	Check the engine system. For 2002 vehicle, see SYSTEM & COMPONENT TESTING - GS300, GS430, IS300 & LS430 under FAULT ISOLATION in ENGINE PERFORMANCE. For 2003 vehicle, see SYSTEM & COMPONENT TESTING under FAULT ISOLATION in ENGINE PERFORMANCE.

⁽⁸⁾	Check the supplemental restraint system. For 2002 vehicle, see AIR BAG RESTRAINT SYSTEMS article. For 2003 vehicle, see AIR BAG RESTRAINT SYSTEMS article.

⁽⁹⁾	Check the front light (body No. 5) control system. For 2002, see BODY CONTROL SYSTEMS article. For 2003, see appropriate BODY CONTROL SYSTEMS article.

⁽¹⁰⁾	Check the combination meter system. See appropriate INSTRUMENT PANELS article.

⁽¹¹⁾	Check the combination switch control system. See appropriate INSTRUMENT PANELS article.

⁽¹²⁾	Check the rain sensor system. See appropriate WIPER/WASHER article.

⁽¹³⁾	Check the anti-lock brake and vehicle skid control systems. See appropriate ANTI-LOCK article in BRAKES.

⁽¹⁴⁾	Check the audio system. Further diagnosis information is not available.

⁽¹⁵⁾	Check the passenger side junction block (body No. 3) control system. For 2002, see BODY CONTROL SYSTEMS article. For 2003, see appropriate BODY CONTROL SYSTEMS article.

⁽¹⁶⁾	Check the rear window defogger system. See appropriate REAR WINDOW DEFOGGER & HEATED MIRRORS article.

⁽¹⁷⁾	Check the LEXUS link system. Further diagnosis information is not available.

PROBLEM SYMPTOM INDEX (DOOR LOCK, WINDOW & SECURITY SYSTEMS)

Symptom

Suspected Area ⁽¹⁾

Anti-Theft System (Door Lock System Is Normal)

⁽²⁾⁽³⁾⁽⁴⁾

Door Lock System

⁽²⁾⁽⁵⁾

Door Lock System (Key Confinement Prevention Function)

⁽²⁾⁽⁶⁾⁽⁵⁾

Door Closer System

⁽⁵⁾

Engine Immobilizer System

⁽⁶⁾⁽⁷⁾

Luggage Compartment Door Opener System

⁽⁴⁾⁽³⁾⁽²⁾

Luggage Compartment Door Closer System

⁽⁴⁾⁽³⁾⁽²⁾

Power Window Control System

⁽⁸⁾

Remote Keyless Entry System (Door Lock System Is Normal)

⁽⁹⁾⁽⁴⁾⁽¹⁰⁾⁽⁵⁾

⁽¹⁾	Perform test procedures in order listed under suspected area.

⁽²⁾	Check the anti-theft system. See appropriate ANTI-THEFT SYSTEM article.

⁽³⁾	Check the driver side junction block (body No. 2) control system. For 2002, see BODY CONTROL SYSTEMS article. For 2003, see appropriate BODY CONTROL SYSTEMS article.

⁽⁴⁾	Check the luggage room junction block ECU control system. For 2002, see BODY CONTROL SYSTEMS article. For 2003, see appropriate BODY CONTROL SYSTEMS article.

⁽⁵⁾	Check appropriate door system. See appropriate POWER DOOR LOCKS, TRUNK LID & FUEL DOOR RELEASE article.

⁽⁶⁾	Check the engine immobilizer system. See appropriate ENGINE IMMOBILIZER SYSTEM article.

⁽⁷⁾	Check the engine system. For 2002, see SELF-DIAGNOSTICS - LS430 under FAULT ISOLATION in ENGINE PERFORMANCE. For 2003, see SELF-DIAGNOSTICS - LS 430 .

⁽⁸⁾	Check the power window system. See appropriate POWER WINDOWS article.

⁽⁹⁾	Check the remote keyless entry system. See appropriate REMOTE KEYLESS ENTRY article.

⁽¹⁰⁾	Check the moon roof system. See appropriate MOON ROOF article.

PROBLEM SYMPTOM INDEX (DRIVER INFORMATION SYSTEM)

Symptom

Suspected Area ⁽¹⁾

Combination Meter (Gauges, Warning Lights, Indicator Lights, Buzzer)

⁽²⁾

Clock

⁽³⁾⁽²⁾

Multi Information Display

⁽²⁾⁽⁴⁾

Key Remainder System

⁽²⁾⁽⁵⁾⁽⁶⁾

LEXUS Park Assist System

⁽⁷⁾⁽⁸⁾

LEXUS Navigation System

⁽⁹⁾⁽⁴⁾⁽¹⁰⁾

Seat Belt Warning System

⁽²⁾⁽¹¹⁾⁽¹⁰⁾

Driving Position Memory System

⁽¹²⁾

⁽¹⁾	Perform test procedures in order listed under suspected area.

⁽²⁾	Check the combination meter system. See appropriate INSTRUMENT PANELS article.

⁽³⁾	Check the A/C system. See appropriate AUTOMATIC A/C-HEATER SYSTEMS article in HVAC.

⁽⁴⁾	Check the steering pad switch system. See appropriate STEERING COLUMN SWITCHES article.

⁽⁵⁾	Check the engine immobilizer system. See appropriate ENGINE IMMOBILIZER SYSTEM article.

⁽⁶⁾	Check the door lock system. See appropriate POWER DOOR LOCKS, TRUNK LID & FUEL DOOR RELEASE article.

⁽⁷⁾	Check the LEXUS park assist system. See appropriate PARKING ASSIST SYSTEM in WARNING SYSTEM.

⁽⁸⁾	Check the rain sensor system. See appropriate WIPER/WASHER SYSTEM article.

⁽⁹⁾	Check the LEXUS navigation system. Further diagnosis information is not available.

⁽¹⁰⁾	Check the passenger side junction block (body No. 3) control system. For 2002, see BODY CONTROL SYSTEMS article. For 2003, see appropriate BODY CONTROL SYSTEMS article.

⁽¹¹⁾	Check the driver side junction block (body No. 2) control system. For 2002, see BODY CONTROL SYSTEMS article. For 2003, see appropriate BODY CONTROL SYSTEMS article.

⁽¹²⁾	Check the power seat control system. See appropriate POWER & HEATED SEATS article.

PROBLEM SYMPTOM INDEX (ILLUMINATION & LIGHTING SYSTEMS)

Symptom

Suspected Area ⁽¹⁾

Illumination System

Buckle Illumination

⁽²⁾⁽³⁾⁽⁴⁾

Door Courtesy Light

⁽⁵⁾

Illumination System (Switch Illuminations, Combination Meter Illumination)

⁽⁶⁾

Illuminated Entry System (Illumination Is Normal)

⁽⁶⁾⁽⁷⁾⁽⁵⁾

Illumination & Interior Light System (Vanity Light, Interior Light, Front Personal Light, Step Light, Ignition Key Illumination)

⁽⁷⁾

Outer Step Light Does Not Light Up (In Outer Mirror)

⁽⁸⁾⁽⁵⁾

Luggage Compartment Light

⁽⁹⁾

Lighting System

Automatic Light Control System (Headlight Is Normal)

⁽⁶⁾⁽⁹⁾⁽¹⁰⁾⁽¹¹⁾⁽¹²⁾

Back-Up Light System

⁽⁶⁾⁽⁹⁾⁽¹³⁾

Front Fog Light System (Headlight Is Normal)

⁽⁶⁾⁽¹⁴⁾⁽¹¹⁾

Front Parking Light &/Or Front Clearance Light

⁽⁶⁾⁽¹¹⁾

Headlight Beam Level Control System (Headlight Is Normal)

⁽⁷⁾⁽¹⁰⁾

Headlight System (Hi Beam Or Flash)

⁽⁶⁾⁽¹⁴⁾⁽¹¹⁾

Headlight System (Low Beam)

⁽⁶⁾⁽¹⁴⁾

License Plate Light

⁽⁶⁾⁽⁹⁾

Light Auto Turn Off System (Headlight Is Normal)

⁽⁶⁾⁽¹⁵⁾⁽¹¹⁾⁽⁵⁾⁽¹⁶⁾

Side Marker Light

⁽⁶⁾⁽¹¹⁾

Stop Light System

⁽⁶⁾⁽⁹⁾

Taillight System &/Or Turn Signal & Hazard Warning System

⁽⁶⁾⁽¹⁴⁾⁽⁹⁾

⁽¹⁾	Perform test procedures in order listed under suspected area.

⁽²⁾	Check the driver side junction block (body No. 2) control system (driver belt). For 2002, see BODY CONTROL SYSTEMS article. For 2003, see appropriate BODY CONTROL SYSTEMS article.

⁽³⁾	Check the passenger side junction block (body No. 3) control system (passenger belt). For 2002, see BODY CONTROL SYSTEMS article. For 2003, see appropriate BODY CONTROL SYSTEMS article.

⁽⁴⁾	Check the luggage room junction block ECU control system (rear belt). For 2002, see BODY CONTROL SYSTEMS article. For 2003, see appropriate BODY CONTROL SYSTEMS article.

⁽⁵⁾	See appropriate AUTOMATIC HEADLIGHTS & LIGHTING SYSTEMS article.

⁽⁶⁾	Check the driver side junction block (body No. 2) control system. For 2002, see BODY CONTROL SYSTEMS article. For 2003, see appropriate BODY CONTROL SYSTEMS article.

⁽⁷⁾	Check the passenger side junction block (body No. 3) control system. For 2002, see BODY CONTROL SYSTEMS article. For 2003, see appropriate BODY CONTROL SYSTEMS article.

⁽⁸⁾	Check the passenger side junction block ECU. For 2002, see BODY CONTROL SYSTEMS article. For 2003, see appropriate BODY CONTROL SYSTEMS article.

⁽⁹⁾	Check the luggage room junction block ECU control system. For 2002, see BODY CONTROL SYSTEMS article. For 2003, see appropriate BODY CONTROL SYSTEMS article.

⁽¹⁰⁾	Check the combination meter system. See appropriate INSTRUMENT PANEL article.

⁽¹¹⁾	Check the front light (body No. 5) control system. For 2002, see BODY CONTROL SYSTEMS article. For 2003, see appropriate BODY CONTROL SYSTEMS article.

⁽¹²⁾	Check the LEXUS navigation system. Further diagnosis information is not available.

⁽¹³⁾	Check the automatic transmission system. For 2002 vehicle, see DIAGNOSIS - A-650E in TRANSAXLE/TRANSMISSION. For 2003 vehicle, see appropriate DIAGNOSIS - A-650E under AUTOMATIC TRANSMISSION in TRANSAXLE/TRANSMISSION.

⁽¹⁴⁾	Check the combination switch control system. See appropriate STEERING COLUMN SWITCHES article.

⁽¹⁵⁾	Check the engine immobilizer system. See appropriate ENGINE IMMOBILIZER SYSTEM article.

⁽¹⁶⁾	Check the anti-theft system. See appropriate ANTI-THEFT SYSTEM article.

PROBLEM SYMPTOM INDEX (MIRROR, POWER SEAT & SEAT BELT SYSTEMS)

Symptom

Suspected Area ⁽¹⁾

Mirror System

Automatic Glare-Resistant EC Mirror System

⁽²⁾

Remote Control Mirror System &/Or Retract Mirror System

⁽²⁾⁽³⁾

Mirror Heater System

⁽²⁾⁽⁴⁾

Seat & Seat Belt System

Driver's Power Seat System

⁽⁵⁾

Rear Passenger's Power Seat System

⁽⁶⁾⁽⁵⁾⁽⁷⁾

Rear Seat Heater System

⁽⁶⁾⁽⁸⁾

Vibration Seat System

⁽⁹⁾

Power Shoulder Belt Anchorage System

⁽¹⁰⁾⁽³⁾⁽¹¹⁾

Driving Position Memory System

⁽¹²⁾⁽¹³⁾

⁽¹⁾	Perform test procedures in order listed under suspected area.

⁽²⁾	Check the mirror system. See appropriate POWER, ELECTRO CHROMIC & MEMORY MIRROR SYSTEMS article.

⁽³⁾	Check the driver side junction block (body No. 2) control system. For 2002, see BODY CONTROL SYSTEMS article. For 2003, see appropriate BODY CONTROL SYSTEMS article.

⁽⁴⁾	Check the A/C system. See appropriate AUTOMATIC A/C-HEATER SYSTEMS article in HVAC.

⁽⁵⁾	Check the power seat control system. See appropriate POWER & HEATED SEATS article.

⁽⁶⁾	Check the rear seat switch. See appropriate POWER & HEATED SEATS article.

⁽⁷⁾	Check the luggage room junction block ECU control system. For 2002, see BODY CONTROL SYSTEMS article. For 2003, see appropriate BODY CONTROL SYSTEMS article.

⁽⁸⁾	Check the seat heater system. See appropriate POWER & HEATED SEATS article.

⁽⁹⁾	Check the seat vibration system. See appropriate POWER & HEATED SEATS article.

⁽¹⁰⁾	Check the power shoulder belt anchorage system. See appropriate PASSIVE RESTRAINTS article in RESTRAINTS.

⁽¹¹⁾	Check the passenger side junction block (body No. 3) control system. For 2002, see BODY CONTROL SYSTEMS article. For 2003, see appropriate BODY CONTROL SYSTEMS article.

⁽¹²⁾	Check the driving position memory system. See appropriate POWER & HEATED SEATS article.

⁽¹³⁾	Check the tilt and telescopic steering system. See appropriate POWER TILT STEERING COLUMN SYSTEMS article in STEERING.

After problem has been identified and repaired, confirm repairs. See CONFIRMATION TEST under SELF-DIAGNOSTIC SYSTEM.