Lexus ES: System Description
SYSTEM DESCRIPTION
BRIEF DESCRIPTION
(a) The Controller Area Network (CAN) is a serial data communication system for real time application. It is a vehicle multiplex communication system which has a high communication speed and the ability to detect malfunctions.
.png)
(b) Using the CANH and CANL bus lines as a pair, CAN communication is performed using a voltage differential. (A base voltage is applied to the pair of lines and a voltage differential is created when communicating.)
(c) Many ECUs or sensors installed to the vehicle operate by sharing information and communicating with each other.
(d) 2 resistors which are necessary for communication are used in a CAN bus main line.
.png)
DEFINITION OF TERMS
(a) Central bus
(1) The central bus is a term used to describe all buses directly connected to the central gateway ECU (network gateway ECU).
HINT:
A bus is displayed as Bus on the "Communication Bus Check" screen of the Techstream.
(b) Sub bus
(1) A sub bus is a bus that has a gateway function equipped ECU in order to communicate with the central bus and other sub buses.
HINT:
- A sub bus is displayed as Sub bus on the "Communication Bus Check" screen of the Techstream.
- When Sub bus is selected on the "Communication Bus Check" screen, ECUs and sensors connected to non-CAN networks such as LIN may also be displayed in addition to the ECUs and sensors connected to sub buses in the CAN network.
(c) Local bus
(1) A local bus is a bus that does not have the ability to communicate with other buses. ECUs and sensors on a local bus can only communicate with other ECUs and sensors on the same bus.
(d) CAN J/C
(1) A CAN junction connector is a connector that connects branch lines to a main bus.
(e) Main bus
(1) A main bus line is the wire harness that runs between the 2 terminating resistors of a bus.
(f) Branch
(1) A branch line is a wire harness that connects an ECU or sensor to a main bus line.
(g) Terminating resistors
(1) Terminating resistors which maintain a stable signal inside the CAN bus are installed. 2 resistors of 120 Ω each located at each end of the bus are necessary.
READ NEXT:
System Diagram
SYSTEM DIAGRAM (a) The CAN communication system is composed of 5 buses. CAN Main Bus Line Terminating Resistor CAN Branch Line * Gateway Function Equipped ECU Bus Monitor
System Diagram
SYSTEM DIAGRAM (a) The CAN communication system is composed of 5 buses. CAN Main Bus Line Terminating Resistor CAN Branch Line * Gateway Function Equipped ECU Bus Monitor
Parts Location
PARTS LOCATION ILLUSTRATION *1 HEADLIGHT ECU SUB-ASSEMBLY RH *2 BRAKE ACTUATOR ASSEMBLY *3 FORWARD RECOGNITION CAMERA *4 ECM *5 RACK AND PINION POWER STEERING GEAR ASSEMBLY
SEE MORE:
"CHK" message(s) are displayed on the SIGNAL CHECK screen.
DESCRIPTION On the SIGNAL CHECK screen, it is possible to check if the signals sent to the parking assist ECU are normal. Click here HINT:
On the SIGNAL CHECK screen, "OK" (blue) is displayed for items with a normal inspection result or input state.
On the SIGNAL CHECK screen, "CHK" (red) is
BSM (Blind Spot Monitor)
The Blind Spot Monitor is a system
that uses rear side radar sensors
installed on the inner side of the
rear bumper on the left and right
side to assist the driver in confirming
safety when changing lanes.
WARNING
■Cautions regarding the use of the
function
The driver is solely responsibl
