Problem Symptoms Table
WARNING: This page is about a different car, the 2008 Lexus IS F. However, it is still accessible from the selected car via links, so may be relevant.
HINT
- Use the table below to help determine the cause of problem symptoms. If multiple suspected areas are listed, 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 fuses and relays related to this system before inspecting the suspected areas below
Dynamic Radar Cruise Control System
PROBLEM SYMPTOMS CHART
| Symptom | Suspected Area | See |
|---|---|---|
| Main switch cannot be turned ON (CRUISE main indicator light on combination meter does not illuminate) | Cruise control switch circuit | CRUISE CONTROL SWITCH CIRCUIT |
| CRUISE main indicator light circuit | CRUISE MAIN INDICATOR LIGHT CIRCUIT | |
| If the symptoms still occur after the above areas have been inspected and have proven to be normal, replace the ECM (for 2UR-GSE) | 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) | Cruise control switch circuit | CRUISE CONTROL SWITCH CIRCUIT |
| If the symptoms still occur after the above area has been inspected and has proven to be normal, replace the ECM (for 2UR-GSE) | 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) | Cruise control switch circuit | CRUISE CONTROL SWITCH CIRCUIT |
| Stop light switch circuit | DTC P0571 BRAKE SWITCH "A" CIRCUIT | |
| Transmission range sensor circuit (for AA80E) | DTC P0705 TRANSMISSION RANGE SENSOR CIRCUIT MALFUNCTION (PRNDL INPUT) | |
| Shift paddle switch circuit (for AA80E) | SHIFT PADDLE SWITCH CIRCUIT | |
| Vehicle speed sensor circuit | DTC P0500 VEHICLE SPEED SENSOR MALFUNCTION; DTC P0503 VEHICLE SPEED SENSOR "A" INTERMITTENT / ERRATIC / HIGH | |
| Meter/gauge system | HOW TO PROCEED WITH TROUBLESHOOTING | |
| If the symptoms still occur after the above areas have been inspected and have proven to be normal, replace the ECM (for 2UR-GSE) | ECM | |
| While vehicle is driven with cruise control, the control is canceled (CRUISE main indicator light remains on) | Cruise control switch circuit | CRUISE CONTROL SWITCH CIRCUIT |
| Vehicle speed sensor circuit | DTC P0500 VEHICLE SPEED SENSOR MALFUNCTION; DTC P0503 VEHICLE SPEED SENSOR "A" INTERMITTENT / ERRATIC / HIGH | |
| Stop light switch circuit | DTC P0571 BRAKE SWITCH "A" CIRCUIT | |
| Meter/gauge system | HOW TO PROCEED WITH TROUBLESHOOTING | |
| Transmission range sensor circuit (for AA80E) | DTC P0705 TRANSMISSION RANGE SENSOR CIRCUIT MALFUNCTION (PRNDL INPUT) | |
| Shift paddle switch circuit (for AA80E) | SHIFT PADDLE SWITCH CIRCUIT | |
| If the symptoms still occur after the above areas have been inspected and have proven to be normal, replace the ECM (for 2UR-GSE) | ECM | |
| Hunting (Speed is not constant) | Vehicle speed sensor circuit | DTC P0500 VEHICLE SPEED SENSOR MALFUNCTION; DTC P0503 VEHICLE SPEED SENSOR "A" INTERMITTENT / ERRATIC / HIGH |
| Malfunction in speed meter circuit | SPEEDOMETER MALFUNCTION | |
| Millimeter wave radar sensor power source circuit | MILLIMETER WAVE RADAR SENSOR POWER SOURCE CIRCUIT | |
| Distance control ECU power source circuit | DISTANCE CONTROL ECU POWER SOURCE CIRCUIT | |
| Distance control ECU | TERMINALS OF ECU | |
| If the symptoms still occur after the above areas have been inspected and have proven to be normal, replace the ECM (for 2UR-GSE) | ECM | |
| Vehicle speed setting cannot be canceled (When coast, acceleration, resume, set speed change function is operated with control switch) | Cruise control switch circuit | CRUISE CONTROL SWITCH CIRCUIT |
| If the symptoms still occur after the above area has been inspected and has proven to be normal, replace the ECM (for 2UR-GSE) | ECM | |
| Erroneous detection or lost sight of the vehicle ahead | Clean radar sensor with soft cloth, etc | - |
| Improper aiming of sensor beam axis | MILLIMETER WAVE RADAR SENSOR | |
| Alarm buzzer does not sound | Skid control buzzer circuit | SKID CONTROL BUZZER CIRCUIT |
| Vehicle stability control system | HOW TO PROCEED WITH TROUBLESHOOTING | |
| Millimeter wave radar sensor power source circuit | MILLIMETER WAVE RADAR SENSOR POWER SOURCE CIRCUIT | |
| Distance control ECU power source circuit | DISTANCE CONTROL ECU POWER SOURCE CIRCUIT | |
| Distance control ECU | TERMINALS OF ECU | |
| If the symptoms still occur after the above areas have been inspected and have proven to be normal, replace the ECM (for 2UR-GSE) | ECM | |
| Set distance cannot be changed | Meter/gauge system | HOW TO PROCEED WITH TROUBLESHOOTING |
| Distance control switch circuit | DISTANCE CONTROL SWITCH CIRCUIT | |
| Cruise control switch circuit | CRUISE CONTROL SWITCH CIRCUIT | |
| Distance control ECU | TERMINALS OF ECU | |
| If the symptoms still occur after the above areas have been inspected and have proven to be normal, replace the ECM (for 2UR-GSE) | ECM | |
| No information on the display | Meter/gauge system | HOW TO PROCEED WITH TROUBLESHOOTING |
| If the symptoms still occur after the above area has been inspected and has proven to be normal, replace the ECM (for 2UR-GSE) | ECM | |
| No brake control (when decelerating) | Vehicle stability control system | HOW TO PROCEED WITH TROUBLESHOOTING |
| Distance control ECU power source circuit | DISTANCE CONTROL ECU POWER SOURCE CIRCUIT | |
| Distance control ECU | TERMINALS OF ECU | |
| If the symptoms still occur after the above areas have been inspected and have proven to be normal, replace the ECM (for 2UR-GSE) | ECM | |
| Constant speed mode cannot be turned on | Cruise control switch circuit | CRUISE CONTROL SWITCH CIRCUIT |
| Meter/gauge system | HOW TO PROCEED WITH TROUBLESHOOTING | |
| If the symptoms still occur after the above areas have been inspected and have proven to be normal, replace the ECM (for 2UR-GSE) | ECM | |
| Vehicle speed cannot be canceled with wiper HI (Including automatic wiper) | Ram sensor circuit | RAIN SENSOR CIRCUIT |
| Wiper switch circuit | WIPER AND WASHER SWITCH CIRCUIT | |
| Distance control ECU | TERMINALS OF ECU | |
| If the symptoms still occur after the above areas have been inspected and have proven to be normal, replace the ECM (for 2UR-GSE) | ECM | |
| Setting cannot be canceled in SNOW mode | Pattern select switch circuit (for AA80E) | PATTERN SELECT SWITCH CIRCUIT |
| Automatic transmission system (for AA80E) | SYSTEM DESCRIPTION | |
| If the symptoms still occur after the above areas have been inspected and have proven to be normal, replace the ECM (for 2UR-GSE) | ECM | |
| Unable to adjust (complete) beam axis of millimeter wave radar sensor | Check for DTC P1570 | DTC CHECK / CLEAR |
| Check position, distance and angle of reflector | MILLIMETER WAVE RADAR SENSOR | |
| Check installation of millimeter wave radar sensor | MILLIMETER WAVE RADAR SENSOR | |
| Millimeter wave radar sensor | MILLIMETER WAVE RADAR SENSOR | |
| Distance control ECU | TERMINALS OF ECU | |
| If the symptoms still occur after the above areas have been inspected and have proven to be normal, replace the ECM (for 2UR-GSE) | ECM | |
| Cannot change between constant speed control mode and vehicle-to-vehicle distance control mode | Cruise control switch circuit | CRUISE CONTROL SWITCH CIRCUIT |
| Millimeter wave radar sensor power source circuit | MILLIMETER WAVE RADAR SENSOR POWER SOURCE CIRCUIT | |
| Distance control ECU | TERMINALS OF ECU | |
| If the symptoms still occur after the above areas have been inspected and have proven to be normal, replace the ECM (for 2UR-GSE) | ECM |