Mirror Adjust Switch Circuit
- Connect Lexus Hand-Held Tester (scan tool) to Data Link Connector 3 (DLC3). Turn ignition and tester on. Select DATALIST mode on tester. Check voltage while operating mirror adjust switch. If scan tool is not available, remove tilt and telescopic ECU with harness connectors connected. Turn ignition on. Measure voltage between 12-pin ECU connector (T8) terminal No. 1 (Brown/Red wire) and 22-pin ECU connector (T9) terminal No. 4 (Light Green wire). See Figure.
- Operate mirror adjust switch in each position and note voltage reading. See MIRROR ADJUST SWITCH VOLTAGE table. If all voltages are as specified, go to TROUBLE SHOOTING and identify next circuit to be checked. If all voltages are not as specified, go to next step. If voltage in only certain directions is not as specified, replace switch.MIRROR ADJUST SWITCH VOLTAGE
Switch Position Volts Off 4.70 Up 1.35-1.65 Down 3.03-3.57 Left 3.62-4.18 Right 2.35-2.85 - Disconnect 10-pin mirror switch wiring harness connector. Measure resistance between mirror switch connector terminals No. 7 and No. 9. See Fig 1. Operate manual switch in each position and note resistance. See MIRROR ADJUST SWITCH RESISTANCE table. If resistances are as specified, go to next step. If resistances are not as specified, replace mirror switch.
- Check wiring harness between tilt and telescopic ECU and mirror switch. See WIRING DIAGRAMS. Repair as necessary. If wiring harness is okay, check ECU pin voltages. See PIN VOLTAGE TESTS. Repair as necessary. If no problem is found, replace tilt and telescopic ECU.
MIRROR ADJUST SWITCH RESISTANCE
| Switch Position | Ohms |
|---|---|
| Up | 100 |
| Down | 470 |
| Left | 800 |
| Right | 250 |