System Operation Check

WARNING: This page is about a different car, the 2002 Lexus RX 300. However, it is still accessible from the selected car via links, so may be relevant.

Trouble shooting of a body control 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.
Inspect the multiplex communication system and confirm that there is no trouble by the basic inspection and DTC check. See PRE-CHECK under SELF-DIAGNOSTIC under MULTIPLEX COMMUNICATION SYSTEM article under COMMUNICATION DEVICES in ACCESSORIES & EQUIPMENT.

Determine problem symptom.

For anti-theft system problem, see PROBLEM SYMPTOM INDEX (ANTI-THEFT SYSTEM) table.
For door lock control or wireless door lock control problem, see PROBLEM SYMPTOM INDEX (DOOR LOCK CONTROL & WIRELESS DOOR LOCK CONTROL) table.
For rear wiper/washer, light control or other problem, see PROBLEM SYMPTOM INDEX (REAR WIPER/WASHER, LIGHT CONTROL & OTHERS) table.

PROBLEM SYMPTOM INDEX (ANTI-THEFT SYSTEM)

Symptom

Suspected Area ⁽¹⁾

No Alerting Condition Is Operated (System Cannot Be Set)

⁽²⁾⁽³⁾⁽⁴⁾⁽⁵⁾⁽⁶⁾⁽⁷⁾⁽⁸⁾

Cannot Be Canceled When IG Is ON With A Key

⁽³⁾⁽⁹⁾⁽⁸⁾

Cannot Be Canceled When Unlocking The Back Door With A Key

⁽⁶⁾⁽⁸⁾

Some Of The System Does Not Operate (Headlight Does Not Light Up)

⁽¹⁰⁾⁽⁸⁾

Taillight Does Not Light Up

⁽¹¹⁾⁽⁸⁾

Anti-Theft Horn Or Horn Does Not Sound

⁽¹²⁾⁽¹³⁾⁽⁸⁾

Hazard Does Not Light Up

⁽¹⁴⁾⁽⁸⁾

During Warning Condition, Cannot Be Canceled By Unlocking The Door With A Key

⁽³⁾⁽¹⁵⁾⁽⁸⁾

During Warning Condition, Cannot Be Canceled By Unlocking The Door With A Key (Transmitter)

⁽¹⁶⁾⁽¹⁷⁾⁽⁸⁾

During Warning Condition, Cannot Be Cancelled by Turning The ACC Or ON With A Key

⁽⁹⁾⁽³⁾⁽⁸⁾

System Is Operated For More Than 60 Seconds

⁽⁸⁾

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

⁽²⁾	Check the security indicator circuit. See ANTI-THEFT INDICATOR CIRCUIT under CIRCUIT TESTS.

⁽³⁾	Check the key unlock warning switch circuit. See KEY UNLOCK WARNING SWITCH CIRCUIT under CIRCUIT TESTS.

⁽⁴⁾	Check the courtesy switch circuit. See AUTOMATIC HEADLIGHTS & LIGHTING article under HEADLIGHTS in ACCESSORIES & EQUIPMENT.

⁽⁵⁾	Check the engine hood courtesy switch circuit. See ENGINE HOOD COURTESY SWITCH CIRCUIT under CIRCUIT TESTS.

⁽⁶⁾	Check the back door courtesy switch circuit. See REAR INTERIOR LIGHT & BACK DOOR COURTESY SWITCH CIRCUIT under CIRCUIT TESTS.

⁽⁷⁾	Check any door ECU.

⁽⁸⁾	Check the body ECU.

⁽⁹⁾	Check the ignition switch. See STEERING COLUMN SWITCHES article in ACCESSORIES & EQUIPMENT.

⁽¹⁰⁾	Check the headlight relay circuit. See HEADLIGHT RELAY CIRCUIT under CIRCUIT TESTS.

⁽¹¹⁾	Check the taillight relay circuit. See TAILLIGHT RELAY CIRCUIT under CIRCUIT TESTS.

⁽¹²⁾	Check the security horn circuit. See ANTI-THEFT HORN CIRCUIT under CIRCUIT TESTS.

⁽¹³⁾	Check the horn circuit. See HORN CIRCUIT under CIRCUIT TESTS.

⁽¹⁴⁾	Check the hazard circuit. See HAZARD SWITCH CIRCUIT under CIRCUIT TESTS.

⁽¹⁵⁾	Check the driver or passenger door ECU.

⁽¹⁶⁾	Check the transmitter. See REMOTE KEYLESS ENTRY article under DOOR LOCKS & ANTI-THEFT SYSTEMS in ACCESSORIES & EQUIPMENT.

⁽¹⁷⁾	Check the wireless tuner circuit. See WIRELESS DOOR LOCK TUNER CIRCUIT under CIRCUIT TESTS.

PROBLEM SYMPTOM INDEX (DOOR LOCK CONTROL & WIRELESS DOOR LOCK CONTROL)

Symptom

Suspected Area ⁽¹⁾

Door Lock Control

Lock Or Unlock Cannot Be Operated With Door Lock Control SW

⁽²⁾⁽³⁾

Door Key Linked Function Does Not Operate

⁽²⁾⁽³⁾

Key Confinement Prevention Function Does Not Operate

⁽⁴⁾⁽³⁾

Wireless Door Lock Control

All Function Of Wireless Door Lock Control System Do Not Operate

⁽⁵⁾⁽⁶⁾⁽⁴⁾⁽³⁾

Lock (Or Unlock) Function Does Not Operate

⁽⁷⁾⁽⁸⁾⁽³⁾

Automatic Lock Function Operates Even If Any Door Is Opened Within 30 Seconds After All Doors Are Unlocked By Wireless Door Lock Control System

⁽⁹⁾⁽⁸⁾⁽³⁾

Wireless Door Lock Operates, But Buzzer Does Not Sound

⁽¹⁰⁾⁽³⁾

Buzzer Sounds, But Wireless Door Lock Function Does Not Operate

⁽³⁾

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

⁽²⁾	Check the appropriate door ECU (driver or passenger).

⁽³⁾	Check the body ECU.

⁽⁴⁾	Check the key unlock switch circuit. See KEY UNLOCK WARNING SWITCH CIRCUIT under CIRCUIT TESTS.

⁽⁵⁾	Check the transmitter. See REMOTE KEYLESS ENTRY article under DOOR LOCKS & ANTI-THEFT SYSTEMS in ACCESSORIES & EQUIPMENT.

⁽⁶⁾	Check the wireless tuner circuit. See WIRELESS DOOR LOCK TUNER CIRCUIT under CIRCUIT TESTS.

⁽⁷⁾	Check the appropriate door unlock detection switch circuit. See POWER DOOR LOCKS & LIFTGATE article under DOOR LOCKS & ANTI-THEFT SYSTEMS in ACCESSORIES & EQUIPMENT.

⁽⁸⁾	Check any door ECU.

⁽⁹⁾	Check the appropriate door courtesy switch circuit. See AUTOMATIC HEADLIGHTS & LIGHTING article under HEADLIGHTS in ACCESSORIES & EQUIPMENT.

⁽¹⁰⁾	Check the wireless door lock buzzer circuit. WIRELESS DOOR LOCK BUZZER CIRCUIT under CIRCUIT TESTS.

PROBLEM SYMPTOM INDEX (REAR WIPER/WASHER, LIGHT CONTROL & OTHERS)

Symptom

Suspected Area ⁽¹⁾

Light Control

Automatic Light Control Does Not Operate

⁽²⁾⁽³⁾⁽⁴⁾

Auto Turn-Off Does Not Operate

⁽⁵⁾⁽⁶⁾⁽⁷⁾⁽⁴⁾

Others

Does Not Operate The Illuminated Entry

⁽⁸⁾⁽⁴⁾

A/C Panel & Multi Display Does Not Deteriorate

⁽⁹⁾⁽⁴⁾

Rear Wiper & Washer

Rear Wiper Does Not Operate

⁽¹⁰⁾⁽¹¹⁾⁽⁴⁾

Rear Washer Does Not Operate

⁽¹²⁾⁽¹³⁾⁽¹⁴⁾

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

⁽²⁾	Check the light sensor circuit. See DTC B1244/44: LIGHT SENSOR CIRCUIT MALFUNCTION under DIAGNOSTIC TESTS under MULTIPLEX COMMUNICATION SYSTEM article under COMMUNICATION DEVICES in ACCESSORIES & EQUIPMENT.

⁽³⁾	Check the headlight control switch circuit. See LIGHT CONTROL SWITCH CIRCUIT under CIRCUIT TESTS.

⁽⁴⁾	Check the body ECU.

⁽⁵⁾	Check the driver side door courtesy switch circuit. See AUTOMATIC HEADLIGHTS & LIGHTING article under HEADLIGHTS in ACCESSORIES & EQUIPMENT.

⁽⁶⁾	Check the ignition switch. See STEERING COLUMN SWITCHES article in ACCESSORIES & EQUIPMENT.

⁽⁷⁾	Check the driver door ECU.

⁽⁸⁾	Check the illumination circuit. See ILLUMINATION CIRCUIT under CIRCUIT TESTS.

⁽⁹⁾	Check the rheostat light control unit. See INSTRUMENT PANEL article in ACCESSORIES & EQUIPMENT.

⁽¹⁰⁾	Check the wiper switch circuit. See WIPER/WASHER SYSTEMS article in ACCESSORIES & EQUIPMENT.

⁽¹¹⁾	Check the rear wiper motor circuit. See WIPER/WASHER SYSTEMS article in ACCESSORIES & EQUIPMENT.

⁽¹²⁾	Check the washer switch circuit. See WIPER/WASHER SYSTEMS article in ACCESSORIES & EQUIPMENT.

⁽¹³⁾	Check the washer motor. See WIPER/WASHER SYSTEMS article in ACCESSORIES & EQUIPMENT.

⁽¹⁴⁾	Check the wiring harness.

Inspect the body control system circuits. See CIRCUIT TESTS .
After problem has been identified and repaired, confirm repairs. See CONFIRMATION TEST under SELF-DIAGNOSTIC SYSTEM.