System Operation Check

WARNING: This page is about a different car, the 2002 Lexus LX 470. 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. See PROBLEM SYMPTOM INDEX table.

PROBLEM SYMPTOM INDEX

Symptom

Suspected Area ⁽¹⁾

Anti-Theft System

No Alerting Condition Is Operated (System Cannot Be Set)

⁽²⁾⁽³⁾⁽⁴⁾⁽⁵⁾⁽⁶⁾⁽⁷⁾

System Operated For More Than 60 Seconds

⁽⁷⁾

Door Lock Control

Lock Or Unlock Cannot Be Operated With Door Lock Control SW

⁽⁸⁾⁽⁷⁾

Door Key Linked Function Does Not Operate

⁽⁹⁾⁽⁷⁾

Key Confinement Prevention Function Does Not Operate

⁽³⁾⁽⁷⁾

Light Control

Auto Turn-Off Does Not Operate

⁽¹⁰⁾⁽¹¹⁾⁽⁷⁾

Others

Illuminated Entry Does Not Operate

⁽¹²⁾⁽⁷⁾

Rear Wiper & Washer

Rear Wiper Does Not Operate

⁽¹³⁾⁽¹⁴⁾⁽⁷⁾

Rear Washer Does Not Operate

⁽¹³⁾⁽¹⁵⁾⁽¹⁶⁾

Rear Wiper Does Not Operate Only At HI Speed

⁽⁷⁾

Rear Wiper Does Not Operate When Washer Switch Is ON

⁽¹³⁾⁽⁷⁾

Wireless Door Lock Control

All Functions Of Wireless Door Lock Control System Do Not Operate

⁽¹⁷⁾⁽³⁾⁽¹⁸⁾⁽⁷⁾

Lock (Or Unlock) Function Does Not Operate

⁽⁹⁾⁽⁵⁾⁽⁷⁾

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

⁽⁴⁾⁽⁷⁾

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

⁽²⁾	Check the anti-theft indicator light circuit. See ANTI-THEFT SYSTEM article under DOOR LOCKS & ANTI-THEFT SYSTEMS in ACCESSORIES & EQUIPMENT.

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

⁽⁴⁾	Check the door courtesy switch circuit. See DOOR COURTESY SWITCH CIRCUIT under CIRCUIT TESTS.

⁽⁵⁾	Check the door unlock detection switch circuit. See DOOR UNLOCK DETECTION SWITCH CIRCUIT under CIRCUIT TESTS.

⁽⁶⁾	Check the engine hood courtesy switch circuit. See ANTI-THEFT SYSTEM article under DOOR LOCKS & ANTI-THEFT SYSTEMS in ACCESSORIES & EQUIPMENT.

⁽⁷⁾	Check the body ECU.

⁽⁸⁾	Check the door lock control switch circuit. See DOOR LOCK CONTROL SWITCH CIRCUIT under CIRCUIT TESTS.

⁽⁹⁾	Check the door key lock and unlock switch circuit. See DOOR KEY LOCK & UNLOCK SWITCH CIRCUIT under CIRCUIT TESTS.

⁽¹⁰⁾	Check the driver side courtesy switch circuit. See DOOR COURTESY SWITCH CIRCUIT under CIRCUIT TESTS.

⁽¹¹⁾	Check the ignition switch. See IGNITION SWITCH POWER SOURCE CIRCUIT under CIRCUIT TESTS.

⁽¹²⁾	Check the illumination circuit. See ILLUMINATION CIRCUIT under CIRCUIT TESTS.

⁽¹³⁾	Check the rear wiper and washer switch circuit. See REAR WIPER & WASHER SWITCH CIRCUIT under CIRCUIT TESTS.

⁽¹⁴⁾	Check the rear wiper motor circuit. see REAR WIPER MOTOR & RELAY CIRCUIT under CIRCUIT TESTS.

⁽¹⁵⁾	Check the rear washer motor. See WIPER/WASHER & HEADLIGHT CLEANER SYSTEMS article under WIPER/WASHER SYSTEMS in ACCESSORIES & EQUIPMENT.

⁽¹⁶⁾	Check the wire harness.

⁽¹⁷⁾	Check the transmitter. See REMOTE KEYLESS ENTRY SYSTEM article under DOOR LOCKS & ANTI-THEFT SYSTEMS in ACCESSORIES & EQUIPMENT.

⁽¹⁸⁾	Check the wireless door lock ECU. REMOTE KEYLESS ENTRY SYSTEM article under DOOR LOCKS & ANTI-THEFT SYSTEMS in ACCESSORIES & EQUIPMENT.

Inspect the body control system circuits. See CIRCUIT TESTS .
After repairs have been completed, confirm that problem has been eliminated. Operate the system under same conditions recorded for original complaint. If problem is no longer present, repair has corrected problem. If problem is still present, further diagnosis and repair is required.