Problem Symptoms Table
WARNING: This page is about a different car, the 2007 Lexus GX 470. However, it is still accessible from the selected car via links, so may be relevant.
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:
PROBLEM SYMPTOM TABLE
| Symptom | Suspected Area | Reference |
|---|---|---|
| Main switch cannot be turned ON. (Cruise indicator light in combination meter is not lit.) | 1. Cruise control switch circuit | CRUISE CONTROL SWITCH CIRCUIT |
| 2. CRUISE MAIN indicator light circuit | CRUISE MAIN INDICATOR LIGHT CIRCUIT | |
| 3. ECM | REMOVAL | |
| Vehicle speed setting cannot be done. (Although indicator light in combination meter is lit when the main switch is turned ON, they go off when vehicle speed is set.) | 1. Cruise control switch circuit | CRUISE CONTROL SWITCH CIRCUIT |
| 2. ECM | REMOVAL | |
| Setting cannot be done. (Indicator light in combination meter is lit when the main switch is turned ON and they remain ON while setting.) | 1. Cruise control switch circuit | CRUISE CONTROL SWITCH CIRCUIT |
| 2. Stop light switch circuit | DTC P0571 BRAKE SWITCH "A" CIRCUIT | |
| 3. PNP switch circuit | DTC P0705 TRANSMISSION RANGE SENSOR CIRCUIT MALFUNCTION (PRNDL INPUT) | |
| 4. Combination meter system | HOW TO PROCEED WITH TROUBLESHOOTING | |
| 5. ECM | REMOVAL | |
| While the vehicle is driving with cruise control, the set control is canceled. (Indicator light and CRUISE remain ON.) | 1. Cruise control switch circuit | CRUISE CONTROL SWITCH CIRCUIT |
| 2. Vehicle speed sensor circuit | DTC P0500 VEHICLE SPEED SENSOR MALFUNCTION; DTC P0503 VEHICLE SPEED SENSOR "A" INTERMITTENT / ERRATIC / HIGH | |
| 3. Stop light switch circuit | DTC P0571 BRAKE SWITCH "A" CIRCUIT | |
| 4. CRUISE MAIN indicator light circuit | CRUISE MAIN INDICATOR LIGHT CIRCUIT | |
| 5. PNP switch circuit | DTC P0705 TRANSMISSION RANGE SENSOR CIRCUIT MALFUNCTION (PRNDL INPUT) | |
| 6. ECM | REMOVAL | |
| Hunting (Speed is not constant.) | 1. Vehicle speed sensor circuit | DTC P0571 BRAKE SWITCH "A" CIRCUIT |
| 2. ECM | REMOVAL | |
| Setting cannot be cancelled. (When Coast, Acceleration, Resume, Set speed change and Control switch are operated.) | 1. Cruise control switch circuit | CRUISE CONTROL SWITCH CIRCUIT |
| 2. ECM | REMOVAL | |
| DTC is not output, or is output when should not be. | 1. Diagnosis circuit | TC AND CG TERMINAL CIRCUIT |
| 2. ECM | REMOVAL | |
| CRUISE MAIN indicator light does not light up. | 1. Cruise control switch circuit | CRUISE CONTROL SWITCH CIRCUIT |
| 2. CRUISE MAIN indicator light circuit | CRUISE MAIN INDICATOR LIGHT CIRCUIT | |
| 3. ECM | REMOVAL |