TROUBLE SHOOTING
Note. Prior to trouble shooting, ensure no problems exist in multiplex communications. If problems exist, repair multiplex control system before trouble shooting. See MULTIPLEX COMMUNICATIONS article.
Note. Check circuits and components in listed order. If circuits or components are okay, return to trouble shooting and identify next circuit to be checked.
SELF-DIAGNOSTIC SYSTEM
Turn ignition off. Connect Lexus Hand-Held Tester (scan tool) to Data Link Connector 3 (DLC3), located under left side of instrument panel, left of steering column. Turn ignition and scan tool on. Using manufacturer's instructions, use scan tool to check for Diagnostic Trouble Codes (DTCs). After repairs, use scan tool to clear DTCs. If DTCs exist, go to appropriate test. See DIAGNOSTIC TROUBLE CODE IDENTIFICATION table.
| Code | Definition |
|---|---|
| B2602 | Key Unlock Warning Switch Circuit Malfunction |
| B2603 | Tilt & Telescopic Manual Switch Circuit Malfunction |
| B2610 | Tilt Position Sensor Or Motor Circuit |
| B2611 | Telescopic Position Sensor Or Motor Circuit |
| B2620 | ECU Power Source Circuit Malfunction |
| B2621 | Communication Interruption |
DIAGNOSTIC TROUBLE CODE IDENTIFICATION
Testing
Disconnect key unlock warning switch connector. Check continuity between switch connector terminals No. 1 and 2. (Scheme 4) Continuity should exist when key is in ignition. Continuity should not exist when key is out of ignition. If continuity is not as specified, replace switch. If continuity is as specified, check continuity between switch terminal No. 1 (White/Black wire) and ground. Check continuity of Yellow wire between switch terminal No. 2 and body ECU No. 2. See WIRING DIAGRAMS. Repair as necessary.
Scheme 4
Check tilt and telescopic manual switch. See MANUAL SWITCH CIRCUIT in SYSTEM TESTS. Replace as necessary. If switch is okay, check ECU pin voltages. See PIN VOLTAGE TESTS. Repair as necessary. If no problem is found, replace tilt and telescopic ECU.
Check actuator power supply circuit. See ACTUATOR POWER SUPPLY CIRCUIT in SYSTEM TESTS. Repair as necessary. Check tilt motor circuit. See TILT MOTOR CIRCUIT in SYSTEM TESTS. Repair as necessary. Check ECU pin voltages. See PIN VOLTAGE TESTS. Repair as necessary. If no problem is found, replace tilt and telescopic ECU.
Check actuator power supply circuit. See ACTUATOR POWER SUPPLY CIRCUIT in SYSTEM TESTS. Repair as necessary. Check telescopic motor circuit. See TELESCOPIC MOTOR CIRCUIT in SYSTEM TESTS. Repair as necessary. Check ECU pin voltages. See PIN VOLTAGE TESTS. Repair as necessary. If no problem is found, replace tilt and telescopic ECU.
Ensure battery is fully charged (11 volts or more). Check tilt and telescopic ECU power supply circuit. See TILT & TELESCOPIC ECU POWER SUPPLY CIRCUIT in SYSTEM TESTS. Repair as necessary. Check ECU pin voltages. See PIN VOLTAGE TESTS. Repair as necessary. If no problem is found, replace tilt and telescopic ECU.
Check multiplex control system. See MULTIPLEX CONTROL SYSTEMS article.