Tech Tips
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 fuses and relays related to this system before inspecting the suspected areas below.
Problem symptoms may occur if the electric power control system's functions malfunction. Follow the HOW TO PROCEED WITH TROUBLESHOOTING procedures.
| Symptom | Suspected Area | See page |
|---|---|---|
| Main switch cannot be turned ON (Cruise control indicator light No. 1 meter ECU sub-assembly does not illuminate) | Cruise control switch circuit | |
| CRUISE main indicator light circuit | ||
| Driving support ECU | ||
| ECM (for 1UR-FSE) | ||
| ECM (for 1UR-FE) | ||
| Vehicle speed setting cannot be performed (Cruise control indicator light on No. 1 meter ECU sub-assembly illuminates when main switch is turned ON, but turns off when operating SET function) | Cruise control switch circuit | |
| Driving support ECU | ||
| ECM (for 1UR-FSE) | ||
| ECM (for 1UR-FE) | ||
| Vehicle speed setting cannot be performed (Cruise control indicator light on No. 1 meter ECU sub-assembly illuminates when main switch is turned ON and remains illuminated when operating SET function) | Cruise control switch circuit | |
| Stop light switch circuit | ||
| Park/neutral position switch (for AA80F) | ||
| Park/neutral position switch (for AA80E) | ||
| Transmission control switch circuit (for AA80F) | ||
| Transmission control switch circuit (for AA80E) | ||
| Shift paddle switch circuit (w/ Shift Paddle Switch) | ||
| No. 1 meter ECU sub-assembly | ||
| Driving support ECU | ||
| ECM (for 1UR-FSE) | ||
| ECM (for 1UR-FE) | ||
| While vehicle is driven with cruise control, set control is canceled (Cruise control indicator light remains illuminated) | Cruise control switch circuit | |
| Skid control ECU (for LHD) | ||
| Skid control ECU (for RHD) | ||
| CAN communication system (for LHD) | ||
| CAN communication system (for RHD) | ||
| Stop light switch circuit | ||
| CRUISE main indicator light circuit | ||
| Park/neutral position switch (for AA80F) | ||
| Park/neutral position switch (for AA80E) | ||
| Driving support ECU | ||
| ECM (for 1UR-FSE) | ||
| ECM (for 1UR-FE) | ||
| Hunting (Speed is not constant) | Skid control ECU (for LHD) | |
| Skid control ECU (for RHD) | ||
| CAN communication system (for LHD) | ||
| CAN communication system (for RHD) | ||
| Speedometer malfunction | ||
| Millimeter wave radar sensor power source circuit | ||
| Driving support ECU power source circuit | ||
| Driving support ECU | ||
| ECM (for 1UR-FSE) | ||
| ECM (for 1UR-FE) | ||
| Vehicle speed setting cannot be canceled (When Coast, Acceleration, Resume, Set speed change and control switch are operated) | Cruise control switch circuit | |
| Driving support ECU | ||
| ECM (for 1UR-FSE) | ||
| ECM (for 1UR-FE) | ||
| Erroneous detection or lost sight of vehicle in front | Clean radar sensor with soft cloth, etc. | - |
| Improper aiming of sensor beam axis | - | |
| Warning buzzer does not sound | Warning buzzer | |
| Electronically control brake system | ||
| Millimeter wave radar sensor power source circuit | ||
| Driving support ECU power source circuit | ||
| Driving support ECU | ||
| ECM (for 1UR-FSE) | ||
| ECM (for 1UR-FE) | ||
| Set distance cannot be changed | Distance control switch circuit | |
| CAN communication system (for LHD) | ||
| CAN communication system (for RHD) | ||
| Driving support ECU | ||
| ECM (for 1UR-FSE) | ||
| ECM (for 1UR-FE) | ||
| No display | Meter / gauge system | |
| CAN communication system (for LHD) | ||
| CAN communication system (for RHD) | ||
| Driving support ECU | ||
| No brake control (when decelerating) | Electronically control brake system | |
| Driving support ECU power source circuit | ||
| CAN communication system (for LHD) | ||
| CAN communication system (for RHD) | ||
| Driving support ECU | ||
| Constant speed control mode cannot be turned on | Cruise control switch circuit | |
| Meter / gauge system | ||
| ECM (for 1UR-FSE) | ||
| ECM (for 1UR-FE) | ||
| Constant speed control mode cannot be turned on | Front millimeter wave radar sensor | |
| Cruise control switch circuit | ||
| Skid control ECU (for LHD) | ||
| Skid control ECU (for RHD) | ||
| Park/neutral position switch (for AA80F) | ||
| Park/neutral position switch (for AA80E) | ||
| ECM (for 1UR-FSE) | ||
| ECM (for 1UR-FE) | ||
| Transmission control switch circuit (for AA80F) | ||
| Transmission control switch circuit (for AA80E) | ||
| Shift paddle switch circuit (w/ Shift Paddle Switch) | ||
| Stop light switch | ||
| CAN communication system (for LHD) | ||
| CAN communication system (for RHD) | ||
| Driving support ECU | ||
| Vehicle speed cannot be canceled with wiper HI (Including automatic wiper) | Windshield wiper switch | |
| Driving support ECU | ||
| Unable to adjust beam axis of front millimeter wave radar sensor | Check for DTC C1A10 | |
| Check position, distance and angle of reflector | - | |
| Check installation of front millimeter wave radar sensor | - | |
| Front millimeter wave radar sensor | ||
| Driving support ECU | ||
| System cannot change between constant speed control mode and vehicle-to-vehicle distance control mode | Cruise control switch circuit | |
| Driving support ECU | ||
| Dynamic radar cruise control cannot be canceled | Inspect VSC OFF switch | - |
| Both VSC and TRC are turned off | - | |
| The TRC is operated for a certain amount of time | - | |
| Operating the VSC system | - | |
| When the wiper is in the HI mode |