The mileage is only 1000km, the Nissan New Teana car equipped with 2.5L engine and CVT transmission. In the course of driving, the ABS indicator light often lights up, sometimes it will go off quickly after lighting, sometimes it will extinguish in a few minutes. Troubleshooting: detailed inquiries about the customer's fault related information, customer description said that the car was less than a month after the purchase of the ABS indicator light appeared, the failure frequency is more frequent, sometimes a short distance, the fault will appear more than three times, and the occurrence of a few seconds will be immediately extinguished, but in the bad road The lights will be extinguished after a few minutes when the indicator lights are on. Read fault code with CONSULT-II diagnostic instrument: engine system fault U1001-CAN communication circuit; ABS, IPDM E/ R, BCM failure U1000-CAN communication circuit. By consulting the maintenance manual, in CAN communication, the control unit is connected by two communication lines (CAN H line, CAN L line), so that less lines can be used for high rate information transmission. Each control unit can transmit / receive data, but only selectively reads the required data. Dongfeng Nissan's interpretation of this type of fault code is the communication failure of the control unit. The fault code can be cleared, but when the ABS indicator lights up again after running, the fault code appears again. Integrated customer and fault code analysis, fault is intermittent fault, can first check from the CAN line, so first check whether there is bad contact in the connection parts of each CAN line, re plug the related wire bundle joint, and carefully check the terminal and pin of the connector at the same time. Normal. According to the circuit diagram 1 Analysis: the measurement of No. 18 pin power supply voltage is 12V, normal; the measurement of CAN data line 26 and 15 pin resistance between the pins is 60 Omega, normal; the iron lap is normal. According to the analysis of circuit diagram 2, the interface between the measured data connection interface and the ABS system actuator unit is normal. Because it is a new car, it is difficult to disassemble and check. The CAN line has been checked for a while. After the delivery, the customer was asked to observe the fault finding characteristics. The customer came to the store third days to reflect that the ABS indicator light appeared in the course of driving, but the failure phenomenon before the shop disappeared. After last check, there is no problem with CAN line connection. The wiring harness of ABS main pump is connected well. Then the ABS general pump is checked. It can be seen from the circuit diagram that it is controlled by the ABS control unit (ABS total pump) itself. It is initially suspected that the internal line is loose or the internal tie - in is bad. Because it is unable to disassemble and analyze it, it is temporarily replaced by the total ABS pump, and the vehicle is tested intermittently. In order to reappear the vehicle fault, the fault appeared again in the second day after the replacement, the ABS indicator light was lighted, and the vehicle was detected again in time. The voltage of the No. 18 pin power supply was 12V, normal; the measurement of the resistance value between the CAN data line 26 and the 15 pin was 604, and the normal ABS grounding wire (E35) was measured. Without grounding, check the connection point of the grounding wire and find the loosening of the left side girders. Therefore, the final cause of the fault was caused by poor tie up and the fault location was E35. Tighten the E35 tie rail and troubleshooting after trial run. For this kind of fault, it is very tedious and not easy to find the fault point in the process of eliminating the fault. Therefore, when the intermittent fault is excluded, the detection effect is best when the fault appears, and the wrong way can be avoided, and the fault location can be found in time and accurately, and it can be eliminated. Comment: the fault of this car is relatively simple: but the author is basically correct in checking the fault of the car: two fault codes are read by the CONSULT-II diagnostic instrument: engine system fault U1001-CAN communication circuit; ABS, IPDM E/R, BCM fault U1000-CAN communication circuit, and the meaning of these two fault codes is this control sheet The element cannot communicate with other control units. The appearance will make us think there is something wrong with the CAN line. And the resistance value between the CAN data line 26 and the pin 15 is 60 ohms and normal two. Next, we should consider the ABS power supply and the grounding power. It is this way of thinking that quickly finds fault. This kind of iron lashing condition is generally the car bump after the failure, we have encountered in the maintenance process has also encountered due to sheet metal spray led to the engine undesirable phenomenon.