System Operation Check

WARNING: This page is about a different car, the 2003 Lexus RX 300 and 2002 Lexus RX 300. However, it is still accessible from the selected car via links, so may be relevant.

Trouble shooting of an anti-theft 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.
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⁾

System Cannot Be Set

⁽²⁾⁽³⁾⁽⁴⁾⁽⁵⁾⁽⁶⁾⁽⁷⁾⁽⁸⁾⁽⁹⁾⁽¹⁰⁾⁽¹¹⁾

System Cannot Be Canceled When Ignition Switch Is Turned To ACC With Key

⁽³⁾⁽¹²⁾⁽⁸⁾⁽¹³⁾⁽⁷⁾

System Cannot Be Canceled When Luggage Compartment Door Is Unlocked With Key

⁽⁶⁾⁽⁸⁾⁽⁷⁾

System Does Not Operate When Engine Hood Is Opened

⁽⁵⁾⁽⁸⁾⁽⁷⁾

System Does Not Operate When Door Is Opened Or Unlocked Without Using A Key Or Transmitter

⁽¹⁴⁾⁽⁹⁾⁽¹⁵⁾⁽⁸⁾⁽¹⁰⁾⁽⁴⁾⁽⁷⁾⁽¹¹⁾

System Does Not Operate When Ignition Switch Is Turned To ACC Without Using A Key Or Transmitter

⁽¹²⁾⁽³⁾⁽⁸⁾⁽⁷⁾⁽¹¹⁾

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

⁽¹⁶⁾⁽⁷⁾⁽⁸⁾

Some Of System Does Not Operate (Taillight Does Not Light Up)

⁽¹⁷⁾⁽⁷⁾⁽⁸⁾

Some Of System Does Not Operate (Anti-Theft Horn Or Horn Does Not Sound)

⁽¹⁸⁾⁽¹⁹⁾⁽²⁰⁾⁽²¹⁾⁽⁷⁾⁽⁸⁾

While Warning Is Given, System Cannot Be Canceled By Unlocking The Door With Key Or Transmitter

⁽²²⁾⁽⁸⁾⁽⁷⁾⁽⁹⁾⁽¹⁵⁾⁽¹⁰⁾⁽¹¹⁾

While Warning Is Given, System Cannot Be Canceled By Turning Ignition Switch To ON With Key

⁽¹²⁾⁽³⁾⁽¹³⁾⁽²³⁾⁽⁸⁾⁽⁷⁾

System Operates For More Then 60 Seconds

⁽⁸⁾

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

⁽²⁾	Check the indicator light. See ANTI-THEFT INDICATOR LIGHT under COMPONENT TESTS.

⁽³⁾	Check the key unlock warning switch. See KEY UNLOCK WARNING SWITCH under COMPONENT TESTS under STEERING COLUMN SWITCHES article in ACCESSORIES & EQUIPMENT.

⁽⁴⁾	Check the appropriate door unlock detection switch. See POWER DOOR LOCKS & LIFTGATE article under DOOR LOCKS & ANTI-THEFT SYSTEMS in ACCESSORIES & EQUIPMENT.

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

⁽⁶⁾	Check the back door courtesy switch. See DOOR COURTESY SWITCH (BACK) under COMPONENT TESTS in AUTOMATIC HEADLIGHTS & LIGHTING article under HEADLIGHTS in ACCESSORIES & EQUIPMENT.

⁽⁷⁾	Check the wire harness.

⁽⁸⁾	Check the body ECU. See BODY CONTROL SYSTEM article under COMMUNICATION DEVICES in ACCESSORIES & EQUIPMENT.

⁽⁹⁾	Check the driver door ECU.

⁽¹⁰⁾	Check the multiplex communication circuit. See MULTIPLEX COMMUNICATION SYSTEM article under COMMUNICATION DEVICES in ACCESSORIES & EQUIPMENT.

⁽¹¹⁾	Check the transmitter.

⁽¹²⁾	Check the ignition switch. See IGNITION SWITCH under COMPONENT TESTS under STEERING COLUMN SWITCHES article in ACCESSORIES & EQUIPMENT.

⁽¹³⁾	Check the RADIO NO. 2 fuse located in the instrument panel junction block.

⁽¹⁴⁾	Check the appropriate door courtesy switch. See AUTOMATIC HEADLIGHTS & LIGHTING article under HEADLIGHTS in ACCESSORIES & EQUIPMENT.

⁽¹⁵⁾	Check the passenger door ECU.

⁽¹⁶⁾	Check the headlight system. See AUTOMATIC HEADLIGHTS & LIGHTING article under HEADLIGHTS in ACCESSORIES & EQUIPMENT.

⁽¹⁷⁾	Check the taillight system. See AUTOMATIC HEADLIGHTS & LIGHTING article under HEADLIGHTS in ACCESSORIES & EQUIPMENT.

⁽¹⁸⁾	Check the anti-theft horn. See ANTI-THEFT HORN under COMPONENT TESTS.

⁽¹⁹⁾	Check the horn. See HORN under COMPONENT TESTS under STEERING COLUMN SWITCHES article in ACCESSORIES & EQUIPMENT.

⁽²⁰⁾	Check the horn relay. See RELAYS under COMPONENT TESTS under STEERING COLUMN SWITCHES article in ACCESSORIES & EQUIPMENT.

⁽²¹⁾	Check the HORN fuse located in the engine room junction block.

⁽²²⁾	Check the appropriate door key lock and unlock switch. See POWER DOOR LOCKS & LIFTGATE article under DOOR LOCKS & ANTI-THEFT SYSTEMS in ACCESSORIES & EQUIPMENT.

⁽²³⁾	Check the GAUGE fuse located in the instrument panel junction block.

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.