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 engine immobilizer 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.

Perform pre-check. See PRE-CHECK under SELF-DIAGNOSTIC SYSTEM. If there is a normal code, go to PROBLEM SYMPTOM INDEX table. If there is a malfunction code, go to DIAGNOSTIC TROUBLE CODE INDEX table.

PROBLEM SYMPTOM INDEX

Symptom

Suspected Area ⁽¹⁾

Immobilizer Is Not Set (Engine Starts With Key Codes Other Than Registered Key Code)

⁽²⁾

Engine Does Not Start

⁽³⁾⁽⁴⁾⁽⁵⁾⁽⁶⁾⁽²⁾

Security Indicator Is Always ON

⁽⁷⁾⁽⁴⁾⁽²⁾

Security Indicator Is Always ON (Although Code Has Been Registered In Automatic Registration Mode, Indicator Is Not OFF)

⁽⁴⁾⁽⁵⁾⁽⁶⁾⁽²⁾

Security Indicator Is OFF (When DTC Of Immobilizer Is Output)

⁽⁴⁾⁽⁵⁾⁽⁶⁾⁽²⁾

Security Indicator Is OFF (When DTC Of Immobilizer Is Not Output)

⁽⁴⁾⁽²⁾

Security Indicator Is Abnormal Blinking

⁽⁴⁾⁽²⁾

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

⁽²⁾	Check the ECM.

⁽³⁾	Check that the key which did not start the engine has been registered and that it is possible to start with other already registered key codes.

⁽⁴⁾	Check the wiring harness.

⁽⁵⁾	Check the transponder key coil. See TRANSPONDER KEY COIL under COMPONENT TESTS.

⁽⁶⁾	Check the transponder key amplifier.

⁽⁷⁾	Check the security indicator. Finish the automatic registration mode because the mode might still remain.

Inspect circuits and parts of the engine immobilizer system. See DIAGNOSTIC TESTS .
After repairs have been completed, confirm that problem has been eliminated. Operate system under same conditions recorded for original complaint. If problem is no longer present and no DTCs are present, repair has corrected problem. If problem is still present or DTCs are reset, further diagnosis and repair is required.