Lexus IS250 IS220d GSE20 ALE20 - CRUISE CONTROL
DYNAMIC RADAR CRUISE CONTROL SYSTEM - PROBLEM SYMPTOMS TABLE
- HINT:
Use the table below to help determine the cause of the problem symptom. The potential causes of the symptoms are listed in order of probability in the "Suspected Area" column of the table. Check each symptom by checking the suspected areas in the order they are listed. Replace parts as necessary.
Inspect the fuse and relay related to this system before inspecting the suspected areas below.
| Symptom | Suspected area | See page |
| 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. ECM | ||
| 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. ECM | ||
| Vehicle speed setting cannot be done. (CRUISE main indicator light on combination meter illuminates when main switch is turned ON, and remains on when operating SET function.) | 1. Cruise control switch circuit | |
| 2. Stop light switch circuit | ||
| 3. Park/Neutral position switch circuit | ||
| 4. Shift paddle switch circuit | ||
| 5. Vehicle speed sensor circuit | ||
| 6. Transmission control switch circuit | ||
| 7. Combination meter system | ||
| 8. ECM | ||
| While vehicle is driven with cruise control, the control is canceled. (CRUISE main indicator light remains on.) | 1. Cruise control switch circuit | |
| 2. Vehicle speed sensor circuit | ||
| 3. Stop light switch circuit | ||
| 4. Combination meter system | ||
| 5. Park/Neutral position switch circuit | ||
| 5. Shift paddle switch circuit | ||
| 6. ECM | ||
| Hunting (Speed is not constant.) | 1. Vehicle speed sensor circuit | |
| 2. Malfunction in speed meter circuit | ||
| 3. Millimeter wave radar sensor power source circuit | ||
| 4. Distance control ECU power source circuit | ||
| 5. Distance control ECU | ||
| 6. ECM | ||
| Vehicle speed setting cannot be canceled. (When coast, acceleration, resume, set speed change function is operated with control switch.) | 1. Cruise control switch circuit | |
| 2. ECM | ||
| Erroneous detection or lost sight of the vehicle ahead. | 1. Clean radar sensor with soft cloth, etc. | - |
| 2. Improper aiming of sensor beam axis | ||
| Alarm buzzer does not sound. | 1. Buzzer circuit | |
| 2. VSC system | ||
| 3. Millimeter wave radar sensor power source circuit | ||
| 4. Distance control ECU power source circuit | ||
| 5. Distance control ECU | ||
| 6. ECM | ||
| Set distance cannot be changed. | 1. Combination meter system | |
| 2. Distance control switch circuit | ||
| 3. Cruise control switch circuit | ||
| 4. Distance control ECU | ||
| 5. ECM | ||
| No information on the display | 1. Combination meter system | |
| 2. ECM | ||
| No brake control (when decelerating) | 1. VSC system | |
| 2. Distance control ECU power source circuit | ||
| 3. Distance control ECU | ||
| 4. ECM | ||
| Constant speed mode cannot be turned on. | 1. Cruise control switch circuit | |
| 2. Combination meter system | ||
| 3. ECM | ||
| Vehicle speed cannot be canceled with wiper HI. (Including automatic wiper) | 1. Rain sensor system | |
| 2. Wiper switch circuit | ||
| 3. Distance control ECU | ||
| 4. ECM | ||
| Setting cannot be canceled in SNOW mode. | 1. Pattern select switch circuit | |
| 2. Automatic transmission system | ||
| 3. ECM | ||
| Unable to adjust (complete) beam axis of millimeter wave radar sensor. | 1. Check for DTC P1570 | |
| 2. Check position, distance and angle of reflector | ||
| 3. Check installation of millimeter wave radar sensor | ||
| 4. Millimeter wave radar sensor | ||
| 5. Distance control ECU | ||
| 6. ECM | ||
| Cannot change between constant speed control mode and vehicle-to-vehicle distance control mode. | 1. Cruise control switch circuit | |
| 2. Millimeter wave radar sensor power source circuit | ||
| 3. Distance control ECU | ||
| 4. ECM |