A mileage of about 58,000 km of Guangzhou Toyota Camry car (vehicle model ASV50L-JETGKC, engine model for 5AR-H039807), reflects the owner: multiple faults on the car dashboard lights.
Troubleshooting: take the car, first verify symptoms, start the engine, VSC found on the dashboard, ABS, EPS and car key programmer
parking brake lights are on, you can not go out and the engine speed 0 r / min 500 r / min fluctuate back and forth. Connection GTS fault detector, select Automatic connection mode attempts vehicle communication connection, the display can not communicate; select "ASV" models into the still display can not communicate via the manual connection mode; select "KEY REGIST" to enter the manual connection mode, detection to the system "smart entry and start system," but the ECU status as an unknown that the current ECU communication exists, but communication is unstable; while in GTS fault detector, the instrument cluster is detected sometimes, but the background color yellow, indicating that the instrument cluster can sometimes establish communication, but is currently unable to establish communication. Based on the above phenomenon and detection results, may causes are CAN bus main line there is a short or open circuit failure; the relevant ECU or sensor fault CAN car diagnostic tools
communication system connected; CAN bus termination resistor failure; CAN communication signal interference caused a communication error; CAN bus Extension short or open circuit failure. According to general CAN bus line (Figure 1) analysis can determine troubleshooting starting point V bus; Disconnect the negative battery terminal, check the resistance between terminals 14 and the terminal 6 DLC3 diagnostic interface for 65.3Ω (standard value 54Ω ~ 69Ω), open or short fault description DLC3 branch of the main line bus and V does not exist; check DLC3 diagnostic interface terminal resistor between terminals 4 and 6 is greater than 200Ω, check the terminal resistor 14 and the terminal 4 between greater than 200Ω described V bus does not exist for short to ground fault; check the resistance DLC3 diagnostic interface terminal 6 and the terminal 16 is larger than 6 kΩ, check the resistance between terminals 14 and the terminal 16 is greater than 6 kΩ, V bus does not explain the presence of short to power failure. According to the above described main bus inspection does not exist open, short, short circuit to B + or short to ground phenomenon that CAN main bus normal, its possible causes for the extension of the presence of an open CAN bus. Since DLC3 inspection is no longer an exception, and the instrument cluster on the recurring fault detector "CAN Bus Check" screen and disappear, the reference car repair manual feeder CAN bus analysis led to the emergence of possible reasons for the open ECM, and the main body ECU line, SRS ECU and wiring, air conditioning and line amplifiers, power steering ECU and wiring, radio receivers and display its line, line gateway ECU and certification ECU and wiring, steering sensor and wiring, ABSECU its line, AFS ECU and wiring, foxwell
and the gap warning ECU line. In addition to the ECM V on the bus outside the ECU or sensors are disconnected, each ECU measurement V bus terminal CANH and CANL resistance of 120 Ω, when the navigation system when removed and found between a CAN network access compiler (which was disconnected, and the other components of recovery after the loading test, troubleshooting, MIL light is off, the engine tachometer to resume normal work. This shows that the real reason for failure is the car fitted with non-original equipment, thereby resulting in the original car-vehicle network communication error.