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Home >> Lexus >> 2012 >> IS F >> Repair and Diagnosis (Single Page) >> Accessories & Equipment >> Cruise Control Systems >> Dynamic Radar Cruise Control System (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 Refer To
Main switch cannot be turned ON. (CRUISE main indicator light on combination meter does not illuminate.) Cruise control switch circuit Refer to Cruise Control Switch Circuit
CRUISE main indicator light circuit Refer to Cruise Main Indicator Light Circuit
If the symptom still occurs after the above areas have been inspected and have proven to be normal, replace the ECM. (for 2UR-GSE) Refer to COMPONENTS
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 Refer to Cruise Control Switch Circuit
If the symptom still occurs after the above area has been inspected and has proven to be normal, replace the ECM. (for 2UR-GSE) Refer to COMPONENTS
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 Refer to Cruise Control Switch Circuit
Stop light switch circuit Refer to DTC P0571: Brake Switch "A" Circuit
Transmission range sensor circuit (for AA80E) Refer to DTC P0705: Transmission Range Sensor Circuit Malfunction (PRNDL Input)
Shift paddle switch circuit (for AA80E) Refer to Shift Paddle Switch Circuit
Vehicle speed sensor circuit Refer to DTC P0500: Vehicle Speed Sensor Malfunction; DTC P0503: Vehicle Speed Sensor "A" Intermittent / Erratic / High
Meter/gauge system Refer to HOW TO PROCEED WITH TROUBLESHOOTING
If the symptom still occurs after the above areas have been inspected and have proven to be normal, replace the ECM. (for 2UR-GSE) Refer to COMPONENTS
While vehicle is driven with cruise control on, the control is canceled. (CRUISE main indicator light remains on.) Cruise control switch circuit Refer to Cruise Control Switch Circuit
Vehicle speed sensor circuit Refer to DTC P0500: Vehicle Speed Sensor Malfunction; DTC P0503: Vehicle Speed Sensor "A" Intermittent / Erratic / High
Stop light switch circuit Refer to DTC P0571: Brake Switch "A" Circuit
Meter/gauge system Refer to HOW TO PROCEED WITH TROUBLESHOOTING
Transmission range sensor circuit (for AA80E) Refer to DTC P0705: Transmission Range Sensor Circuit Malfunction (PRNDL Input)
Shift paddle switch circuit (for AA80E) Refer to Shift Paddle Switch Circuit
If the symptom still occurs after the above areas have been inspected and have proven to be normal, replace the ECM. (for 2UR-GSE) Refer to COMPONENTS
Hunting (Speed is not constant.) Vehicle speed sensor circuit Refer to DTC P0500: Vehicle Speed Sensor Malfunction; DTC P0503: Vehicle Speed Sensor "A" Intermittent / Erratic / High
Malfunction in speed meter circuit Refer to Speedometer Malfunction
Millimeter wave radar sensor power source circuit Refer to Millimeter Wave Radar Sensor Power Source Circuit
Distance control ECU power source circuit Refer to Distance Control ECU Power Source Circuit
Distance control ECU Refer to TERMINALS OF ECU 
If the symptom still occurs after the above areas have been inspected and have proven to be normal, replace the ECM. (for 2UR-GSE) Refer to COMPONENTS
Vehicle speed setting cannot be canceled. (When coast, acceleration, resume, set speed change function is operated with control switch.) Cruise control switch circuit Refer to Cruise Control Switch Circuit
If the symptom still occurs after the above area has been inspected and has proven to be normal, replace the ECM. (for 2UR-GSE) Refer to COMPONENTS
Erroneous detection or lost sight of the vehicle ahead Clean radar sensor with soft cloth, etc. -
Improper aiming of sensor beam axis Refer to ADJUSTMENT
Alarm buzzer does not sound. Skid control buzzer circuit Refer to Skid Control Buzzer Circuit
Vehicle stability control system Refer to HOW TO PROCEED WITH TROUBLESHOOTING
Millimeter wave radar sensor power source circuit Refer to Millimeter Wave Radar Sensor Power Source Circuit
Distance control ECU power source circuit Refer to Distance Control ECU Power Source Circuit
Distance control ECU Refer to TERMINALS OF ECU 
If the symptom still occurs after the above areas have been inspected and have proven to be normal, replace the ECM. (for 2UR-GSE) Refer to COMPONENTS
Set distance cannot be changed. Meter/gauge system Refer to HOW TO PROCEED WITH TROUBLESHOOTING
Distance control switch circuit Refer to Distance Control Switch Circuit
Cruise control switch circuit Refer to Cruise Control Switch Circuit
Distance control ECU Refer to TERMINALS OF ECU 
If the symptom still occurs after the above areas have been inspected and have proven to be normal, replace the ECM. (for 2UR-GSE) Refer to COMPONENTS
No information on the display Meter/gauge system Refer to HOW TO PROCEED WITH TROUBLESHOOTING
If the symptom still occurs after the above area has been inspected and has proven to be normal, replace the ECM. (for 2UR-GSE) Refer to COMPONENTS
No brake control (when decelerating) Vehicle stability control system Refer to HOW TO PROCEED WITH TROUBLESHOOTING
Distance control ECU power source circuit Refer to Distance Control ECU Power Source Circuit
Distance control ECU Refer to TERMINALS OF ECU 
If the symptom still occurs after the above areas have been inspected and have proven to be normal, replace the ECM. (for 2UR-GSE) Refer to COMPONENTS
Constant speed mode cannot be turned on. Cruise control switch circuit Refer to Cruise Control Switch Circuit
Meter/gauge system Refer to HOW TO PROCEED WITH TROUBLESHOOTING
If the symptom still occurs after the above areas have been inspected and have proven to be normal, replace the ECM. (for 2UR-GSE) Refer to COMPONENTS
Vehicle speed cannot be canceled with wiper HI. (Including automatic wiper) Rain sensor circuit Refer to Rain Sensor Circuit
Wiper switch circuit Refer to Wiper and Washer Switch Circuit
Distance control ECU Refer to TERMINALS OF ECU 
If the symptom still occurs after the above areas have been inspected and have proven to be normal, replace the ECM. (for 2UR-GSE) Refer to COMPONENTS
Setting cannot be canceled in SNOW mode. Pattern select switch circuit (for AA80E) Refer to Pattern Select Switch Snow Mode Circuit
Automatic transmission system (for AA80E) Refer to HOW TO PROCEED WITH TROUBLESHOOTING
If the symptom still occurs after the above areas have been inspected and have proven to be normal, replace the ECM. (for 2UR-GSE) Refer to COMPONENTS
Unable to adjust (complete) beam axis of millimeter wave radar sensor. Check for DTC P1570 Refer to DTC P1570: Radar Sensor Malfunction
Check position, distance and angle of reflector Refer to ADJUSTMENT
Check installation of millimeter wave radar sensor Refer to INSTALLATION
Millimeter wave radar sensor Refer to COMPONENTS
Distance control ECU Refer to TERMINALS OF ECU 
If the symptom still occurs after the above areas have been inspected and have proven to be normal, replace the ECM. (for 2UR-GSE) Refer to COMPONENTS
Cannot change between constant speed control mode and vehicle-to-vehicle distance control mode. Cruise control switch circuit Refer to Cruise Control Switch Circuit
Millimeter wave radar sensor power source circuit Refer to Millimeter Wave Radar Sensor Power Source Circuit
Distance control ECU Refer to TERMINALS OF ECU 
If the symptom still occurs after the above areas have been inspected and have proven to be normal, replace the ECM. (for 2UR-GSE) Refer to COMPONENTS