Blind disassembly cause ECU information loss
Before reading the fault code, remove the battery cable (or fuse) and the fault code will automatically disappear. It is very troublesome and time-consuming to obtain the fault information and working conditions and environmental conditions when the fault occurs. Therefore, the battery cables should not be removed at will. It is recommended to connect the positive and negative electrodes with wires to ensure that the power supply is available before proceeding with on-site operation .
2. When the ignition switch is disengaged battery
Regardless of whether the car engine is running or not, the battery cable (or fuses) must not be removed as long as the ignition switch is in the on position. Due to a sudden power failure will make the circuit in the coil produce high instantaneous voltage, and sometimes up to nearly 10000 volts, so that computer ECU and related sensors and other microelectronic devices severely damaged. Across the start of other vehicles or other vehicles across the start and start the car, but also need to turn off the ignition switch, in order to dismantle the jumper cable, the reason ibid.
3. Remove the battery power hazards
Some models may cause the memory (including security code) of auxiliary devices such as window regulators, radios, quartz clocks and the like to be removed at the same time if the battery cables are removed. As a result, the devices can not be used normally. Some models will also activate anti-theft, system lock, Can not start normally, so, for some inadvertently understand the model, must not disassemble the power cord. It is recommended to use wires to connect the positive and negative poles to ensure that the power supply is available before conducting on-site operations.
4. Battery disassembly on the engine performance
After the battery disconnect and then loaded, and sometimes the engine operating conditions will change, the reason may be due to the battery power, the electronic control unit ECU learning correction memory is also eliminated. Based on the data stored in the read-only memory (PROM), the ECU automatically learns the learning control in combination with the current actual operating conditions of the system, so that the engine condition is slightly different. If this happens, after the engine is running for a period of time, the ECU will automatically set up a learning correction memory function, and the bad working condition of the engine will automatically disappear.