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Home >> Lexus >> 2012 >> IS 350C >> Repair and Diagnosis >> Accessories & Equipment >> Cruise Control Systems >> Cruise Control System (Diagnostics - Introduction) >> Cruise Control System >> Problem Symptoms Table >> Problem Symptoms Table
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Problem Symptoms Table

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Be sure to perform the SYMPTOM SIMULATION procedure before replacing the ECM. If these symptoms do not persist, the cause of the problem may be a poor intermittent electrical contact (open or short) of a wire harness or connector.

CRUISE CONTROL SYSTEM

Symptom Suspected Area See
Vehicle speed cannot be set. (The CRUISE main indicator light comes on.) Cruise control switch circuit Refer to Cruise Control Switch Circuit
ECM (2GR-FSE) Refer to REMOVAL
ECM (4GR-FSE) Refer to REMOVAL
Pushing the ON-OFF button does not turn the cruise control system on. (Vehicle speed cannot be set.) Stop light switch circuit Refer to DTC P0571: Brake Switch "A" Circuit
Clutch switch circuit*1 Refer to Clutch Switch Circuit
Vehicle speed sensor circuit Refer to DTC P0500: Vehicle Speed Sensor Malfunction
Cruise control switch circuit Refer to Cruise Control Switch Circuit
Park/Neutral position sensor circuit (2GR-FSE)*2 Refer to DTC P0705: Transmission Range Sensor Circuit Malfunction (PRNDL Input)
Park/Neutral position sensor circuit (4GR-FSE)*2 Refer to DTC P0705: Transmission Range Sensor Circuit Malfunction (PRNDL Input)
Shift paddle switch circuit (2GR-FSE)*2 Refer to Shift Paddle Switch Circuit
Shift paddle switch circuit (4GR-FSE)*2 Refer to Shift Paddle Switch Circuit
ECM (2GR-FSE) Refer to REMOVAL
ECM (4GR-FSE) Refer to REMOVAL
Pushing the ON-OFF button does not turn the cruise control system on. (Vehicle speed can be set.) Cruise main indicator light circuit Refer to Cruise Main Indicator Light Circuit
ECM (2GR-FSE) Refer to REMOVAL
ECM (4GR-FSE) Refer to REMOVAL
The cruise control is canceled while it is operating. Stop light switch circuit Refer to DTC P0571: Brake Switch "A" Circuit
Clutch switch circuit*1 Refer to Clutch Switch Circuit
Park/Neutral position sensor circuit (2GR-FSE)*2 Refer to DTC P0705: Transmission Range Sensor Circuit Malfunction (PRNDL Input)
Park/Neutral position sensor circuit (4GR-FSE)*2 Refer to DTC P0705: Transmission Range Sensor Circuit Malfunction (PRNDL Input)
Shift paddle switch circuit (2GR-FSE)*2 Refer to Shift Paddle Switch Circuit
Shift paddle switch circuit (4GR-FSE)*2 Refer to Shift Paddle Switch Circuit
Cruise control switch circuit Refer to Cruise Control Switch Circuit
Vehicle speed sensor circuit Refer to DTC P0500: Vehicle Speed Sensor Malfunction
ECM (2GR-FSE) Refer to REMOVAL
ECM (4GR-FSE) 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
Cruise main indicator light circuit Refer to Cruise Main Indicator Light Circuit
ECM (2GR-FSE) Refer to REMOVAL
ECM (4GR-FSE) Refer to REMOVAL
Pulling back on the control main switch does not cancel the cruise control. (The CRUISE main indicator light goes off.) ECM (2GR-FSE) Refer to REMOVAL
ECM (4GR-FSE) 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 DTC P0500: Vehicle Speed Sensor Malfunction
Cruise main indicator light circuit Refer to Cruise Main Indicator Light Circuit
ECM (2GR-FSE) Refer to REMOVAL
ECM (4GR-FSE) 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.) Vehicle speed sensor circuit Refer to DTC P0500: Vehicle Speed Sensor Malfunction
ECM (2GR-FSE) Refer to REMOVAL
ECM (4GR-FSE) 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 P0571: Brake Switch "A" Circuit
Cruise main indicator light circuit Refer to Cruise Main Indicator Light Circuit
ECM (2GR-FSE) Refer to REMOVAL
ECM (4GR-FSE) Refer to REMOVAL
Depressing the brake pedal does not cancel the cruise control. (The CRUISE main indicator light goes off.) Stop light switch circuit Refer to DTC P0571: Brake Switch "A" Circuit
ECM (2GR-FSE) Refer to REMOVAL
ECM (4GR-FSE) Refer to REMOVAL
Depressing the clutch pedal does not cancel the cruise control. (The CRUISE main indicator light remains on.)*1 Clutch switch circuit*1 Refer to Clutch Switch Circuit
Cruise main indicator light circuit Refer to Cruise Main Indicator Light Circuit
ECM (4GR-FSE) Refer to REMOVAL
Depressing the clutch pedal does not cancel the cruise control. (The CRUISE main indicator light goes off.)*1 Clutch switch circuit*1 Refer to Clutch Switch Circuit
ECM (4GR-FSE) Refer to REMOVAL
Moving the shift lever does not cancel the cruise control.*2 Park/Neutral position switch circuit (2GR-FSE)*2 Refer to DTC P0705: Transmission Range Sensor Circuit Malfunction (PRNDL Input)
Park/Neutral position switch circuit (4GR-FSE)*2 Refer to DTC P0705: Transmission Range Sensor Circuit Malfunction (PRNDL Input)
Shift paddle switch circuit (2GR-FSE)*2 Refer to Shift Paddle Switch Circuit
Shift paddle switch circuit (4GR-FSE)*2 Refer to Shift Paddle Switch Circuit
ECM (2GR-FSE) Refer to REMOVAL
ECM (4GR-FSE) Refer to REMOVAL
Hunting. (Speed is not constant.) Vehicle speed sensor circuit Refer to DTC P0500: Vehicle Speed Sensor Malfunction
ECM (2GR-FSE) Refer to REMOVAL
ECM (4GR-FSE) Refer to REMOVAL
The CRUISE main indicator light remains blinking. TC and CG terminal circuit Refer to TC and CG Terminal Circuit
ECM (2GR-FSE) Refer to REMOVAL
ECM (4GR-FSE) Refer to REMOVAL

*1: Manual Transmission

*2: Automatic Transmission