Problem Symptoms Table
WARNING: This page is about a different car, the 2006 Lexus RX 400h. However, it is still accessible from the selected car via links, so may be relevant.
DYNAMIC LASER CRUISE CONTROL SYSTEM
PROBLEM SYMPTOMS TABLE (DYNAMIC LASER CRUISE CONTROL SYSTEM)
| Symptom | Suspected area |
|---|---|
| Main switch cannot be turned ON. (CRUISE main indicator light on combination meter does not illuminate.) | 1. CRUISE CONTROL SWITCH CIRCUIT |
| 2. CRUISE MAIN INDICATOR LIGHT CIRCUIT | |
| 3. Hybrid vehicle control ECU. See 2 | |
| Vehicle speed setting cannot be done. (CRUISE main indicator light on combination meter illuminates when main switch is turned ON, but turns off when operating SET function.) | 1. CRUISE CONTROL SWITCH CIRCUIT |
| 2. Hybrid vehicle control ECU. See 2 | |
| Vehicle speed setting cannot be done. (CRUISE main indicator light on combination meter illuminates when main switch is turned ON, and remains illuminated when operating SET function.) | 1. CRUISE CONTROL SWITCH CIRCUIT |
| 2. Stop light switch circuit. See DTC P0571 STOP LIGHT SWITCH CIRCUIT MALFUNCTION | |
| 3. Park/Neutral position switch circuit (DTC P0705) | |
| 4. COMBINATION METER | |
| 5. Hybrid vehicle control ECU. See 2 | |
| While the vehicle is driven with cruise control, the set control is canceled. (CRUISE main indicator light remains illuminated.) | 1. CRUISE CONTROL SWITCH CIRCUIT |
| 2. VEHICLE SPEED SENSOR CIRCUIT | |
| 3. Stop light switch circuit. See DTC P0571 STOP LIGHT SWITCH CIRCUIT MALFUNCTION | |
| 4. CRUISE MAIN INDICATOR LIGHT CIRCUIT | |
| 5. Park/Neutral position switch circuit (DTC P0705) | |
| 6. Hybrid vehicle control ECU. See 2 | |
| Hunting (Speed is not constant.) | 1. VEHICLE SPEED SENSOR CIRCUIT |
| 2. Malfunction in speed meter circuit | |
| 3. LASER SENSOR POWER SOURCE CIRCUIT | |
| 4. DISTANCE CONTROL ECU POWER SOURCE CIRCUIT | |
| 5. DISTANCE CONTROL ECU | |
| 6. Hybrid vehicle control ECU. See 2 | |
| Vehicle speed setting cannot be canceled. (When Coast, Acceleration, Resume, Set speed change and Control switch are operated.) | 1. CRUISE CONTROL SWITCH CIRCUIT |
| 2. Hybrid vehicle control ECU. See 2 | |
| Erroneous detection or lost sight of the vehicle ahead. | 1. Clean laser sensor with soft cloth, etc. |
| 2. Improper aiming of sensor beam axis. See REMOVAL | |
| Alarm buzzer does not sound. | 1. SKID CONTROL BUZZER CIRCUIT |
| 2. VSC system. See HOW TO PROCEED WITH TROUBLESHOOTING | |
| 3. LASER SENSOR POWER SOURCE CIRCUIT | |
| 4. DISTANCE CONTROL ECU POWER SOURCE CIRCUIT | |
| 5. DISTANCE CONTROL ECU | |
| 6. Hybrid vehicle control ECU. See 2 | |
| Set distance cannot be changed. | 1. COMBINATION METER |
| 2. DISTANCE CONTROL SWITCH CIRCUIT | |
| 3. CRUISE CONTROL SWITCH CIRCUIT | |
| 4. Hybrid vehicle control ECU. See 2 | |
| No display | 1. COMBINATION METER |
| 2. Hybrid vehicle control ECU. See 2 | |
| No brake control (when decelerating) | 1. VSC system. See HOW TO PROCEED WITH TROUBLESHOOTING |
| 2. DISTANCE CONTROL ECU POWER SOURCE CIRCUIT | |
| 3. DISTANCE CONTROL ECU | |
| 4. Hybrid vehicle control ECU. See 2 | |
| Constant speed mode cannot be turned on. | 1. CRUISE CONTROL SWITCH CIRCUIT |
| 2. COMBINATION METER | |
| 3. Hybrid vehicle control ECU. See 2 | |
| Vehicle speed cannot be canceled with wiper HI. (Including automatic wiper) | 1. RAIN SENSOR CIRCUIT |
| 2. WIPER AND WASHER SWITCH CIRCUIT | |
| 3. DISTANCE CONTROL ECU | |
| 4. Hybrid vehicle control ECU. See 2 | |
| Setting cannot be canceled in SNOW mode. | 1. Hybrid vehicle control ECU. See 2 |
| Unable to adjust (complete) beam axis of millimeter wave radar sensor. | 1. CHECK FOR DTC P1570 |
| 2. Check position, distance and angle of reflector. See REMOVAL | |
| 3. Check installation of laser sensor. See REMOVAL | |
| 4. LASER SENSOR | |
| 5. DISTANCE CONTROL ECU | |
| 6. Hybrid vehicle control ECU. See 2 | |
| Cannot change between constant speed control mode and vehicle-to-vehicle distance control mode | 1. CRUISE CONTROL SWITCH CIRCUIT |
| 2. Hybrid vehicle control ECU. See 2 |