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 CONTROL SYSTEMS - LS430 article. Check circuits and components in listed order. If circuits or components are okay, return to trouble shooting and identify next circuit to be checked. Perform power tilt steering column system self-diagnostics before performing trouble shooting. See DIAGNOSTIC PROCEDURE under SELF-DIAGNOSTIC SYSTEM.
| Problem | Inspect | |
|---|---|---|
| Manual, Auto Away/Return & Memory Functions Do Not Operate, Stop Part Way Or Do Not Stop | ||
| Tilt & Telescopic | (1) Multiplex Communication System; (2) ECU Power Source Circuit; (3) Key Unlock Warning Switch; (4) Body Control ECU; (2) Actuator Power Source Circuit; (2) Sensor Power Source Circuit; (2) Tilt Motor Circuit; (2) Telescopic Motor Circuit; (5) Tilt & Telescopic ECU | |
| Tilt Only | (1) Multiplex Communication System; (2) Sensor Power Source Circuit; (2) Tilt Motor Circuit; (5) Tilt & Telescopic ECU | |
| Telescopic Only | (1) Multiplex Communication System; (2) Sensor Power Source Circuit; (2) Telescopic Motor Circuit; (5) Tilt & Telescopic ECU | |
| Only Tilt & Telescopic Manual Switch Function Does Not Operate | ||
| Tilt & Telescopic | (1) Multiplex Communication System; (2) Tilt & Telescopic Manual Switch Circuit; (5) Tilt & Telescopic ECU | |
| Tilt Only | (1) Multiplex Communication System; (2) Tilt & Telescopic Manual Switch Circuit; (5) Tilt & Telescopic ECU | |
| Telescopic Only | (1) Multiplex Communication System; (2) Tilt & Telescopic Manual Switch Circuit; (5) Tilt & Telescopic ECU | |
| Only Auto Away/Return Function Does Not Operate | ||
| Away & Return | Check Status Of Auto Away Function Using LEXUS Scan Tool; (1) Multiplex Communication System; (3) Ignition Switch; (3) Key Unlock Warning Switch; (5) Tilt & Telescopic ECU | |
| Away Only | (1) Multiplex Communication System; (3) Key Unlock Warning Switch Circuit; (3) Ignition Switch; (5) Tilt & Telescopic ECU | |
| Return Only | (1) Multiplex Communication System; (3) Key Unlock Warning Switch; (3) Ignition Switch; (5) Tilt & Telescopic ECU | |
| (1) See MULTIPLEX CONTROL SYSTEMS - LS430 article. (2) Perform appropriate test under SYSTEM TESTS . If more than one test is listed, perform tests in order listed. (3) See STEERING COLUMN SWITCHES article. (4) See BODY CONTROL SYSTEMS - LS430 article. (5) Perform TILT & TELESCOPIC ECU PIN VOLTAGE TESTS under PIN VOLTAGE TESTS. Repair or replace components as necessary. | ||
| (1) | See MULTIPLEX CONTROL SYSTEMS - LS430 article. |
| (2) | Perform appropriate test under SYSTEM TESTS . If more than one test is listed, perform tests in order listed. |
| (3) | See STEERING COLUMN SWITCHES article. |
| (4) | See BODY CONTROL SYSTEMS - LS430 article. |
| (5) | Perform TILT & TELESCOPIC ECU PIN VOLTAGE TESTS under PIN VOLTAGE TESTS. Repair or replace components as necessary. |
SYMPTOM DIAGNOSIS
DIAGNOSTIC PROCEDURE
Connect LEXUS or OBDII scan tool to Data Link Connector 3 (DLC3) located under left side of instrument panel. Turn ignition switch to ON position. Using scan tool, check DTCs and freeze frame data. If no DTC is retrieved, see SYMPTOM DIAGNOSIS table under TROUBLE SHOOTING. If any DTCs are retrieved, see POWER TILT COLUMN DTC IDENTIFICATION table. Each DTC will be displayed in order, starting with lowest DTC. Erase DTCs using scan tool.
| DTC | Definition |
|---|---|
| B2602 | Key Unlock Warning Switch Circuit Malfunction |
| B2610 | Tilt Position Sensor Or Motor Circuit Malfunction |
| B2611 | Telescopic Position Sensor Or Motor Circuit Malfunction |
| B2620 | ECU Power Source Circuit Malfunction |
| B2621 | Communication Interruption |
POWER TILT COLUMN DTC IDENTIFICATION
Circuit Description
Signal is sent to tilt and telescopic ECU when ignition switch is turned to ACC, ON or START position.
Diagnosis & Repair
- Turn ignition off. Disconnect key unlock warning switch harness connector. Check continuity between terminals No. 1 and 2 at key unlock warning switch harness connector. (Scheme 2) Insert key in ignition switch. Continuity should exist. Remove key from ignition switch. Continuity should not exist. If continuity is as specified, go to next step. If continuity is not as specified, replace key unlock warning switch.
- Check continuity between ground and terminal No. 1. See «WIRING DIAGRAMS»(ref-27102-S34930120742001010800000). Continuity should exist. If continuity does not exist, repair wiring harness as necessary and retest system operation.
Scheme 2
During normal operation, mechanical limits are outside operating range. DTC B2610 sets when tilt operation stops (limit reached) within normal operating sensor range.
- Check sensor power source circuit. See «SENSOR POWER SOURCE CIRCUIT»(ref-27102-S36254732102001010800000) under SYSTEM TESTS. Repair or replace wiring harness or components as necessary. If circuit is okay, check actuator power source circuit. See «ACTUATOR POWER SOURCE CIRCUIT»(ref-27102-S02680967382001010800000) under SYSTEM TESTS. Repair or replace wiring harness or components as necessary. If circuit is okay, go to next step.
- Check tilt motor circuit. See «TILT MOTOR CIRCUIT»(ref-27102-S11704974492001010800000) under SYSTEM TESTS. Repair or replace wiring harness or components as necessary. If circuit is okay, check tilt and telescopic ECU. See «TILT & TELESCOPIC ECU PIN VOLTAGE TESTS»(ref-27102-S34414153582001010800000) under PIN VOLTAGE TESTS. Replace tilt and telescopic ECU as necessary and retest system operation.
During normal operation, mechanical limits are outside operating range. DTC B2611 sets when telescoping operation stops (limit reached) while within normal operating sensor range.
- Check sensor power source circuit. See «SENSOR POWER SOURCE CIRCUIT»(ref-27102-S36254732102001010800000) under SYSTEM TESTS. Repair or replace wiring harness or components as necessary. If circuit is okay, check actuator power source circuit. See «ACTUATOR POWER SOURCE CIRCUIT»(ref-27102-S02680967382001010800000) under SYSTEM TESTS. Repair or replace wiring harness or components as necessary. If circuit is okay, go to next step.
- Check telescopic motor circuit. See «TELESCOPIC MOTOR CIRCUIT»(ref-27102-S38683834882001010800000) under SYSTEM TESTS. Repair or replace wiring harness or components as necessary. If circuit is okay, check tilt and telescopic ECU. See «TILT & TELESCOPIC ECU PIN VOLTAGE TESTS»(ref-27102-S34414153582001010800000) under PIN VOLTAGE TESTS. Replace tilt and telescopic ECU as necessary and retest system operation.
DTC B2620 sets when tilt and telescopic ECU detects voltage input of 8 volts or less for 10 seconds or more.
Ensure battery is fully charged. Replace battery as necessary. If battery is okay, check tilt and telescopic ECU power source circuit. See ECU POWER SOURCE CIRCUIT under SYSTEM TESTS. Repair or replace wiring harness or components as necessary. If circuit is okay, check tilt and telescopic ECU. See TILT & TELESCOPIC ECU PIN VOLTAGE TESTS under PIN VOLTAGE TESTS. Replace tilt and telescopic ECU as necessary and retest system operation.
Tilt and telescopic ECU forms the multiplex communication network with ECUs of other systems through communication bus. Each ECU outputs specified signals (periodical signals) to network within a fixed period of time to inform other ECUs of its connection to the network. Tilt and telescopic ECU detects connected condition of each ECU based on this signal. DTC B2621 sets when tilt and telescopic ECU detects that periodical signals from another ECU have stopped.
Check multiplex control system. See MULTIPLEX CONTROL SYSTEMS - LS430 article. Repair or replace wiring harness or components as necessary. If multiplex control system is okay, check tilt and telescopic ECU. See TILT & TELESCOPIC ECU PIN VOLTAGE TESTS under PIN VOLTAGE TESTS. Replace tilt and telescopic ECU as necessary and retest system operation.