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Home >> Toyota >> 2012 >> Prius Four >> Repair and Diagnosis (Single Page) >> Accessories & Equipment >> Cruise Control Systems >> Dynamic Radar Cruise Control System (Except Plug-In) (Diagnostics - Introduction) >> Dynamic Radar Cruise Control System >> Problem Symptoms Table >> Problem Symptoms Table
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Problem Symptoms Table

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DYNAMIC RADAR CRUISE CONTROL SYSTEM

Symptom Suspected Area See
The cruise control main switch (ON-OFF button) cannot be turned on. Driving support ECU power source circuit Refer to ECU Power Source Circuit
Cruise control switch circuit Refer to Cruise Control Switch Circuit
Cruise main indicator light circuit Refer to Cruise Main Indicator Light Circuit
Power management control ECU Refer to REMOVAL
Driving support ECU Refer to REMOVAL
Setting cannot be changed between constant speed control mode and vehicle-to-vehicle distance control mode. Cruise control switch circuit Refer to Cruise Control Switch Circuit
Combination meter assembly Refer to PROBLEM SYMPTOMS TABLE
Driving support ECU Refer to REMOVAL
Set distance cannot be changed. Distance control switch circuit Refer to Distance Control Switch Circuit
Combination meter assembly Refer to PROBLEM SYMPTOMS TABLE
Driving support ECU Refer to REMOVAL
Setting cannot be canceled in vehicle-to-vehicle distance control mode. Combination meter assembly Refer to PROBLEM SYMPTOMS TABLE
Millimeter wave radar sensor assembly Refer to REMOVAL
Driving support ECU Refer to REMOVAL
Vehicle speed setting cannot be performed. (The 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 Refer to Cruise Control Switch Circuit
Driving support ECU Refer to REMOVAL
Vehicle speed setting cannot be performed with the constant speed mode. (The cruise main indicator light on combination meter illuminates when main switch is turned on, and remains on when operating SET function is operating.) Stop light switch circuit Refer to DTC C1A05: Stop Light Switch Circuit; DTC C1A4B: Stop Light Relay Circuit
Vehicle speed sensor circuit Refer to HOW TO PROCEED WITH TROUBLESHOOTING
Cruise control switch circuit Refer to Cruise Control Switch Circuit
Hybrid control system Refer to HOW TO PROCEED WITH TROUBLESHOOTING
Driving support ECU Refer to REMOVAL
Vehicle speed setting cannot be performed with the vehicle-to-vehicle distance control mode. (The cruise main indicator light on combination meter illuminates when main switch is turned on, and remains on when SET function is operating.) Millimeter wave radar sensor Refer to REMOVAL
Stop light switch circuit Refer to DTC C1A05: Stop Light Switch Circuit; DTC C1A4B: Stop Light Relay Circuit
Vehicle speed sensor circuit Refer to HOW TO PROCEED WITH TROUBLESHOOTING
Cruise control switch circuit Refer to Cruise Control Switch Circuit
Hybrid control system Refer to HOW TO PROCEED WITH TROUBLESHOOTING
Wiper signal circuit Refer to Wiper Signal Circuit
Electronically controlled brake system Refer to HOW TO PROCEED WITH TROUBLESHOOTING
While vehicle is driven with cruise control on, the control is canceled. Stop light switch circuit Refer to DTC C1A05: Stop Light Switch Circuit; DTC C1A4B: Stop Light Relay Circuit
Hybrid control system Refer to HOW TO PROCEED WITH TROUBLESHOOTING
Electronically controlled brake system Refer to HOW TO PROCEED WITH TROUBLESHOOTING
Cruise control switch circuit Refer to Cruise Control Switch Circuit
Vehicle speed sensor circuit Refer to HOW TO PROCEED WITH TROUBLESHOOTING
Wiper signal circuit Refer to Wiper Signal Circuit
Driving support ECU Refer to REMOVAL
Pulling back on the control main switch does not cancel the cruise control. (The cruise main indicator light remains on.) Cruise control switch circuit Refer to Cruise Control Switch Circuit
Driving support ECU Refer to REMOVAL
Pulling back on the control main switch does not cancel the cruise control. (The cruise main indicator light goes off.) Driving support ECU Refer to REMOVAL
The cruise control is not canceled when vehicle speed drops below the low speed limit. (The cruise main indicator light remains on.) Vehicle speed sensor circuit Refer to HOW TO PROCEED WITH TROUBLESHOOTING
Driving support ECU Refer to REMOVAL
The cruise control is not canceled when vehicle speed drops below the low speed limit. (The cruise main indicator light goes off.) Driving support ECU Refer to REMOVAL
Depressing the brake pedal does not cancel the cruise control. (The cruise main indicator light remains on.) Stop light switch circuit Refer to DTC C1A05: Stop Light Switch Circuit; DTC C1A4B: Stop Light Relay Circuit
Driving support ECU Refer to REMOVAL
Depressing the brake pedal does not cancel the cruise control. (The cruise main indicator light goes off.) Driving support ECU Refer to REMOVAL
Vehicle speed cannot be canceled with wiper HI. (The cruise main indicator light remains on.) Wiper signal circuit Refer to Wiper Signal Circuit
Driving support ECU Refer to REMOVAL
Vehicle speed cannot be canceled with wiper HI. (The cruise main indicator light goes off.) Driving support ECU Refer to REMOVAL
Moving the shift lever does not cancel the cruise control. (The cruise main indicator light remains on.) Hybrid control system Refer to HOW TO PROCEED WITH TROUBLESHOOTING
Driving support ECU Refer to REMOVAL
Moving the shift lever does not cancel the cruise control. (The cruise main indicator light goes off.) Driving support ECU Refer to REMOVAL
Hunting (Speed is not constant.) Vehicle speed sensor circuit Refer to HOW TO PROCEED WITH TROUBLESHOOTING
SFI system Refer to HOW TO PROCEED WITH TROUBLESHOOTING
Hybrid control system Refer to HOW TO PROCEED WITH TROUBLESHOOTING
Driving support ECU Refer to REMOVAL
Even though front millimeter wave radar sensor is not dirty, CLEAN RADAR SENSOR is displayed Millimeter wave radar sensor assembly is dirty -
Adjust front millimeter wave radar sensor assembly Refer to ADJUSTMENT
Millimeter wave radar sensor assembly Refer to REMOVAL
No information on the multi-information display Combination meter assembly Refer to PROBLEM SYMPTOMS TABLE
Beam axis of millimeter wave radar sensor cannot be adjusted (completed). Check position, distance and angle of reflector Refer to ADJUSTMENT
Check installation of millimeter wave radar sensor Refer to INSTALLATION
Millimeter wave radar sensor assembly Refer to REMOVAL
Driving support ECU Refer to REMOVAL
Alarm buzzer does not sound. Skid control buzzer circuit Refer to Skid Control Buzzer Circuit
Electronically controlled brake system Refer to HOW TO PROCEED WITH TROUBLESHOOTING
Millimeter wave radar sensor assembly Refer to REMOVAL
Driving support ECU Refer to REMOVAL
No brake control (when decelerating) Electronically controlled brake system Refer to HOW TO PROCEED WITH TROUBLESHOOTING
Driving support ECU Refer to REMOVAL
The SET indicator light does not illuminate (SET function operates normally) Cruise SET indicator light circuit Refer to Cruise SET Indicator Light Circuit
Driving support ECU Refer to REMOVAL
The cruise main indicator light remains blinking TC and CG terminal circuit Refer to TC and CG Terminal Circuit
Driving support ECU Refer to REMOVAL