Power Tilt Steering Column Systems: Other Lexus LX J100

ACTUATOR POWER SOURCE CIRCUIT

1. Turn ignition switch to OFF position. Remove tilt and telescopic ECU with wiring harness connector attached. Measure voltage by backprobing between terminal No. 4 (Red wire) at 16-pin ECU connector T8 and terminal No. 6 (White/Black wire) at 8-pin ECU connector T7. (Scheme 27) If battery voltage does not exist, go to next step. If battery voltage exists, go to next test listed in «SYMPTOM DIAGNOSIS»(ref-9259-S22888569082000101300000) table under TROUBLE SHOOTING.
2. Measure resistance by backprobing between ground and terminal No. 6 (White/Black wire) at 8-pin ECU connector T7. If resistance is one k/ohms or less, go to next step. If resistance is more than one k/ohms, repair or replace wiring harness or connector between tilt and telescopic ECU and ground connection. See «WIRING DIAGRAMS»(ref-9259-S40290802862000101300000).
3. Inspect for blown POWER fuse (40-amp) located in cowl side junction block, behind left kick panel. If POWER fuse is blown, inspect and repair short in wiring harness between POWER fuse and tilt and telescopic fuse or moon roof control ECU (if equipped). See «WIRING DIAGRAMS»(ref-9259-S40290802862000101300000). If POWER fuse is not blown, inspect for open in wiring harness between tilt and telescopic ECU and battery. Repair or replace as necessary and retest system operation.

Scheme 27

ECU POWER SOURCE CIRCUIT

1. Turn ignition switch to OFF position. Remove tilt and telescopic ECU with wiring harness connectors attached. Measure voltage by backprobing between terminals No. 1 (Blue/White wire) and No. 6 (White/Black wire) at 8-pin ECU connector T7. (Scheme 27) If battery voltage does not exist, go to next step. If battery voltage exists, go to next test listed in «SYMPTOM DIAGNOSIS»(ref-9259-S22888569082000101300000) table under TROUBLE SHOOTING.
2. Measure resistance by backprobing between ground and terminal No. 6 (White/Black wire) at 8-pin ECU connector T7. If resistance is one k/ohms or less, go to next step. If resistance is more than one k/ohms, repair or replace wiring harness or connector between tilt and telescopic ECU and ground connection. See «WIRING DIAGRAMS»(ref-9259-S40290802862000101300000).
3. Inspect for blown ECU-B fuse (15-amp) located in cowl side junction block, behind left kick panel. If ECU-B fuse is blown, check and repair short in wiring harness between ECU-B fuse and tilt and telescopic ECU. See «WIRING DIAGRAMS»(ref-9259-S40290802862000101300000). If ECU-B fuse is not blown, check for open in wiring harness between tilt and telescopic ECU and battery. Repair or replace as necessary and retest system operation.

SENSOR POWER SOURCE CIRCUIT

1. Turn ignition switch to ON position. Remove tilt and telescopic ECU with wiring harness connectors attached. Measure voltage by backprobing between terminals No. 13 (Green/White wire) and No. 14 (Green/Yellow wire) at 16-pin ECU connector T8. (Scheme 27) Also, measure voltage by backprobing between terminals No. 12 (Black/White wire) and No. 10 (Black/Yellow wire) at 16-pin ECU connector T8. If voltage is 4.5-5.5 volts for both measurements, go to next step. If voltage is not 4.5-5.5 volts for both measurements, go to step 3.
2. Inspect wiring harness and connectors for an open between tilt and telescopic ECU, tilt motor and telescopic motor. See «WIRING DIAGRAMS»(ref-9259-S40290802862000101300000). Repair or replace as necessary. If wiring harness and connectors are okay, go to next test listed in «SYMPTOM DIAGNOSIS»(ref-9259-S22888569082000101300000) table under TROUBLE SHOOTING.
3. Inspect wiring harness and connectors for a short between tilt and telescopic ECU, tilt motor and telescopic motor. See «WIRING DIAGRAMS»(ref-9259-S40290802862000101300000). Repair or replace as necessary. If wiring harness and connectors are okay, check tilt and telescopic ECU. See «TILT & TELESCOPIC ECU PIN VOLTAGE TESTS»(ref-9259-S41182956082000101300000) under COMPONENT TESTS. Replace tilt and telescopic ECU as necessary and retest system operation.

TELESCOPIC MOTOR CIRCUIT

Note. If Toyota Hand-Held Tester (scan tool) is available, start test from step 1). If this scan tool is not available, start test from step 2).

1. Connect Toyota Hand-Held Tester to Data Link Connector 3 (DLC3) located under left side of instrument panel. Turn ignition and scan tool on. Select ACTIVE TEST mode on scan tool. Using scan tool, telescope steering column in and out. If steering column does not move, go to next step. If steering column moves, go to next test listed in «SYMPTOM DIAGNOSIS»(ref-9259-S22888569082000101300000) table under TROUBLE SHOOTING.
2. Disconnect 8-pin telescopic motor and 8-pin tilt motor connectors. Remove telescopic motor. See «STEERING COLUMN»(ref-9259-S18451603972000101300000) under REMOVAL & INSTALLATION. Reconnect tilt motor connector to telescopic motor. Operate tilt and telescopic manual switch and confirm operation of telescopic motor. If telescopic motor operates, go to next step. If telescopic motor does not operate, replace telescopic motor and retest system operation.
3. Inspect for open or short in wiring harness or connectors between tilt and telescopic ECU and telescopic motor. See «WIRING DIAGRAMS»(ref-9259-S40290802862000101300000) . Repair or replace as necessary. If wiring harness and connectors are okay, go to next test listed in «SYMPTOM DIAGNOSIS»(ref-9259-S22888569082000101300000) table under TROUBLE SHOOTING.

TILT MOTOR CIRCUIT

Note. If Toyota Hand-Held Tester (scan tool) is available, start test from step 1). If this scan tool is not available, start test from step 2).

1. Connect Toyota Hand-Held Tester to Data Link Connector 3 (DLC3) located under left side of instrument panel. Turn ignition and scan tool on. Select ACTIVE TEST mode on scan tool. Using scan tool, tilt steering column up and down. If steering column does not move, go to next step. If steering column moves, go to next test listed in «SYMPTOM DIAGNOSIS»(ref-9259-S22888569082000101300000) table under TROUBLE SHOOTING.
2. Disconnect 8-pin tilt motor and 8-pin telescopic motor connectors. Remove tilt motor. See «STEERING COLUMN»(ref-9259-S18451603972000101300000) under REMOVAL & INSTALLATION. Connect telescopic motor connector to tilt motor. Operate manual switch and confirm operation of tilt motor. If tilt motor operates, go to next step. If tilt motor does not operate, replace tilt motor and retest system operation.
3. Inspect for open or short in wiring harness or connectors between tilt and telescopic ECU and tilt motor. See «WIRING DIAGRAMS»(ref-9259-S40290802862000101300000) . Repair or replace as necessary. If wiring harness and connectors are okay, go to next test listed in «SYMPTOM DIAGNOSIS»(ref-9259-S22888569082000101300000) table under TROUBLE SHOOTING.

TILT & TELESCOPIC MANUAL SWITCH CIRCUIT

Note. If Toyota Hand-Held Tester (scan tool) is available, start test from step 1). If this scan tool is not available, start test from step 2).

Scheme 28

1. Connect Toyota Hand-Held Tester to Data Link Connector 3 (DLC3) located under left side of instrument panel. Turn ignition and scan tool on. Select DATA LIST mode on scan tool. Read voltages on tester while operating tilt and telescopic manual switch. See «TILT & TELESCOPIC MANUAL SWITCH VOLTAGE»(ref-9259-S31221620692000101300000) table. If all voltages are as specified, go to next test listed in «SYMPTOM DIAGNOSIS»(ref-9259-S22888569082000101300000) table under TROUBLE SHOOTING. If all voltages are not as specified, go to step 3. If voltages in only certain directions are not as specified, replace tilt and telescopic manual switch.
2. If scan tool is not available, remove tilt and telescopic ECU with wiring harness connectors attached. Turn ignition switch to ON position. Measure voltage by backprobing between terminals No. 5 (Violet/Yellow wire) and No. 6 (White/Black wire) at 8-pin ECU connector T7. (Scheme 27) Operate manual switch in each position and note voltage reading. See «TILT & TELESCOPIC MANUAL SWITCH VOLTAGE»(ref-9259-S31221620692000101300000) table. If all voltages are as specified, go to next test listed in «SYMPTOM DIAGNOSIS»(ref-9259-S22888569082000101300000) table under TROUBLE SHOOTING. If all voltages are not as specified, go to next step. If voltages in only certain directions are not as specified, replace tilt and telescopic manual switch. TILT & TELESCOPIC MANUAL SWITCH VOLTAGE Switch Position Voltage Neutral 0-.20 Telescopic Extend 2.05-2.75 Telescopic Retract.65-.95 Tilt Down.30-.50 Tilt Up 1.30-1.70
3. If not previously removed, remove tilt and telescopic ECU with wiring harness connectors attached. Turn ignition switch to ON position. Measure voltage by backprobing between ground and terminal No. 2 (Violet wire) at 8-pin ECU connector T7. If voltage is 4.5-5.5 volts, go to next step. If voltage is not 4.5-5.5 volts, go to step 5.
4. Disconnect 10-pin tilt and telescopic manual switch connector. Measure resistance between terminals No. 4 (Violet/Yellow wire) and No. 9 (Violet wire) at 10-pin manual switch connector. (Scheme 28) Operate manual switch in each position and note resistance. See «TILT & TELESCOPIC MANUAL SWITCH RESISTANCE»(ref-9259-S15236776822000101300000) table. If resistances are as specified, go to next step. If resistances are not as specified, replace tilt and telescopic manual switch. TILT & TELESCOPIC MANUAL SWITCH RESISTANCE Switch Position Ohms Telescopic Extend 160 Telescopic Retract 790 Tilt Down 1,990 Tilt Up 360
5. Inspect for open or short in wiring harness and connectors between tilt and telescopic ECU and manual switch. See «WIRING DIAGRAMS»(ref-9259-S40290802862000101300000). Repair or replace as necessary. If wiring harness and connectors are okay, go to next test listed in «SYMPTOM DIAGNOSIS»(ref-9259-S22888569082000101300000) table under TROUBLE SHOOTING.

TILT & TELESCOPIC ECU PIN VOLTAGE TESTS

Turn ignition switch to ON position. Measure voltage by backprobing between specified tilt and telescopic ECU connector terminals. See TILT & TELESCOPIC ECU PIN VOLTAGES table. (Scheme 27) If voltages are not as specified, repair wiring harness or replace components as necessary. If voltages are as specified, replace tilt and telescopic ECU.

TILT & TELESCOPIC ECU PIN VOLTAGES