Literacy ECU engine fault diagnosis system

Fault self-diagnosis system detects a fault signal after it has been judged as failing, fault information in the form of fault codes stored in the ECU stored in ECU memory. Through certain procedures will fault code fault information in a particular way or displayed. Different models of information displayed in different ways. There are several main:
first, CHECK light flashing trouble codes.
when the engine is working properly when there is no fault, switch on the ignition switch to the "ON" position, the "CHECK" light lit. After starting the engine speed higher than 500r/min this light should go off. Otherwise failure occurs, with special-purpose jumper jumper diagnostic or other operation fault code to "CHECK" lamp must Flash mode is displayed. After troubleshooting, "CHECK" light goes out when the engine speed higher than the 500r/min.
1, bridged with LED lights on the diagnosis of fault diagnosis output terminal, or bridging dedicated detection equipment, as the percentage table, angle table, computer monitor directly read fault codes, or the fault information.
2, by the master computer ECU shell side indicator lights display the fault code.
3, directly by the display on the dashboard display fault codes, information and data.
Second, the fault clears after troubleshooting, fault information is still stored in the ECU cannot be automatically cleaned with the trouble shooting, through operating procedures. Different removal methods are also slightly different, general cleanup method is in the fuse box "EFI" fuse disconnect more than a few seconds, but there are exceptions.
third, the electronic control engine fault diagnosis system using example 1, from dashboard "CHECK" light flashes fault codes, following in Japan Toyota as an example.
Toyota car fault diagnosis system can access the engine, constant speed, automatic transmission, brake ABS, airbags and air conditioning system for fault codes. Caries-this article describes only the adjustment of engine fault codes fault codes access steps:
① throttle valve is in the closed state, the transmission in p or n block, turn off all electrical equipment, the ignition switch is in the "ON" block, the engine does not start. Diagnosis of
using special-purpose jumper TE1 and E1 Jack jumper.
TE1-master ECU fault code diagnosis trigger line E1-ECU connected with a body lift iron ③ dashboard "CHECK" light will blink, in accordance with the sequence of fault display fault codes fault codes and wave.
according to read the fault codes read fault codes table, fault location and nature. Fault code definitions of different models are different. Toyota car part fault code description as shown in the table.
fault code clears the fuse box in the "EFI" fuse unplug for 10 seconds or more, trouble code can be cleared.
2, bridged with LED lights on the diagnosis of fault diagnosis output terminal to read the fault codes, following in Korea Hyundai available as an example and LED lights led European resistance in series with 330-440.
engine ECU diagnostic system in the diagnosis of bridging on analog multimeter, to block DC voltage with a needle, the oscillation frequency to replace the LED light flashes read fault codes.
find the Diagnostics, jumper LED or analog multimeter.
ignition switch reset the lights "ON" position, fault code is beginning to show.
fault code flashing the same as Toyota cars.
Troubleshooting, disconnect the battery cable for 15 seconds to clear the fault codes.
3, with the main side light reading, computer ECU fault codes, following the case of Nissan cars.
Nissan vehicle is the breakdown code access in two ways: one is by the side of the main computer display light display; on the other is the dashboard a red "CHECK" light display. Which Toyota cars use the method is basically the same, we will not repeat, side light, only the main computer display.
computer-side indicator lights display the fault code, fault code retrieval and clearing procedures, there are two:
in the main computer ECU side there is one red and one green light, there is another "TEST" selector switch. Other methods are:
① at the computer "ON" block.
II will "TEST" switch pull to "ON" position.
③ side two indicator lights, directly from the computer read the fault codes. Red light flashing frequency to 10 digits, the green light for the number of digits.
II will "TEST" switch pull to "OFF" position.
II turn ignition switch "OFF", and fault codes to clear.
appears in the main computer side there is only one red light, another with a variable resistance knob hole. It is used:
① place ignition switch in "ON" block.
putting variable resistance spin clockwise twist in the end, after 2 seconds and then counterclockwise Pao, red indicator light Flash reads a set of fault codes.
③ all fault codes after the redeployment, adjustable resistance knob clockwise twist in the end, after 15 seconds, and then counterclockwise Pao. 2 seconds after the ignition switch is in the "OFF" block, fault codes are cleared.
4, instrument panel directly on the display shows fault code fault information, and data.
this way to save the trouble of outward redeployment of access after fault code, but because it makes computer programs more complex and increased manufacturing costs, it is now rarely used in vehicles that run. This article describes the use of methods.
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