解读故障码（Decoding fault codes）.docVIP

解读故障码（Decoding fault codes） Decoding fault codes With the development of automobile technology and modern electronic technology, the application of electronic technology in modern automobile has been quite widely, in order to facilitate troubleshooting, the major car companies are in the electronic control system with fault self diagnosis system. However, I found in the maintenance practice, causes not many fault codes and direct fault indication, the real reason often need to refer to the fault code, according to the fault phenomena, after a careful analysis to determine. If the lack of correct analysis, often make the maintenance work detours, and even go astray. Two examples of maintenance will be analyzed and explained in the hope that readers can help. Example one Fault model: Honda accord 2.2 EFI car. Fault phenomenon: engine fault light; idle, engine jitter serious; exhaust slightly black smoke. According to the driver, the car engine technical condition has been good, since the engine fault lights, idle speed, the engine began to shake, and more and more serious, but the power, economic good. Troubleshooting process: due to the fault lights, the system has the fault code storage, it should first read the fault code. Remove the glove compartment, find the two hole fault diagnosis socket, switch on the ignition switch with a special lead wire, read the fault code 12 from the fault lamp, that is, the exhaust gas recirculation valve position sensor fault. At the time that the sensor and the engine idle jitter is not associated, and most in the EFI car, regardless of engine fault light is bright, as long as the transfer code, basically have two codes, especially the oxygen sensor, but the effects on engine operation did not significantly. As a result, only the peripheral circuit of the EGR valve position sensor is inspected and no abnormalities are observed. After the ECU - IG fuse is removed, the fault remains. The common reason for idle speed is idle control va