DESCRIPTION
When the brake pedal is depressed, the stop light switch assembly sends a signal to the ECM. When the ECM receives this signal, it cancels control of vehicle speed by the cruise control system. The fail-safe function operates to enable normal driving even if there is a malfunction in the stop light signal circuit. The cancellation condition occurs when voltage is applied to terminal STP. When the brake is applied, voltage is normally applied to terminal STP of the ECM through the STOP fuse and the stop light switch assembly, and the ECM cancels control of vehicle speed by the cruise control system.
| DTC No. | Detection Item | DTC Detection Condition | Trouble Area |
|---|---|---|---|
| P0571 | Brake Switch "A" Circuit | When voltage of STP terminal and that of ST1- terminal of ECM are less than 1 V for 0.5 sec. or more | Stop light switch assembly Harness or connector ECM |
Scheme 39
This DTC indicates an abnormality in the ECM.
| DTC No. | Detection Item | DTC Detection Condition | Trouble Area |
|---|---|---|---|
| P0575 | Cruise Control Input Circuit | When either of following conditions is met: Cruise control input signal abnormal Stop light switch assembly input signal abnormal | ECM |
HINT
The ECM receives signals from each sensor to control all functions of the cruise control system. When a malfunction is detected, the fail-safe function operates until the engine switch is turned off.
The ECM receives signals from the skid control ECU (brake actuator assembly) via CAN communication.
| DTC No. | Detection Item | DTC Detection Condition | Trouble Area |
|---|---|---|---|
| U0122 | Lost Communication with Vehicle Dynamics Control Module | While vehicle speed is 40 km/h (25 mph) or more and cruise switch (ON/OFF button) is on, data cannot be received from skid control ECU (brake actuator assembly) for 2.5 seconds or more. | CAN communication system ECM Skid control ECU (brake actuator assembly) |
This DTC is output when the vehicle stability control system has a problem. Check the vehicle stability control system when this DTC P1578 is output.
| DTC No. | Detection Item | DTC Detection Condition | Trouble Area |
|---|---|---|---|
| P1578 | Brake System Malfunction | There is an vehicle stability control system malfunction | Vehicle stability control system ECM |
The cruise control switch is used to turn the cruise control system on and off, as well as operate 7 functions: SET, - (COAST), TAP-DOWN, RES (RESUME), + (ACCEL), TAP-UP and CANCEL. The SET, TAP-DOWN and - (COAST) functions, and the RES (RESUME), TAP-UP and + (ACCEL) functions are operated with the same switch. The cruise control switch is an automatic return type switch which turns on only while operating it in the direction of each arrow and turns off after releasing it. The internal contact points of the cruise control switch turn on with switch operation. Then the ECM reads the voltage value that has been changed by the switch operation to control the SET, - (COAST), RES (RESUME), + (ACCEL), and CANCEL functions.
Scheme 40
- The ECM turns on the cruise control indicator by sending indicator output demand signals to the combination meter assembly using CAN communication.
- The cruise control indicator illuminates when the cruise control system has been turned on using the cruise control switch (ON/OFF button). If a malfunction is detected, the cruise control indicator goes off and a warning message is displayed.
- The cruise control indicator circuit uses CAN communication. If the cruise control indicator is not functioning correctly, check for CAN communication DTCs before troubleshooting this circuit.
- The ECM turns on the SET indicator by sending indicator output demand signals to the combination meter assembly using CAN communication.
- The cruise control SET indicator illuminates when the cruise control system is controlling vehicle speed.
- The cruise control indicator circuit uses CAN communication. If the cruise control indicator is not functioning correctly, check for CAN communication DTCs before troubleshooting this circuit.
Connecting terminals TC and CG of the DLC3 causes the cruise control system to enter self-diagnostic mode.
HINT
When a particular warning light remains blinking, a ground short in the wiring of terminal TC of the DLC3 or an internal ground short in the relevant ECU is suspected.
