1. Did not read the electronic engine control (ECU) records the error code can be removed before the battery cable g5266, hd438
Because the error code read before hastily removed the battery cable or unplug the power fuse, due to the interruption of power supply ECU stored in random access memory in the code error will be automatically removed. If you want access to new information because it is necessary to repeat or reproduce the error occurred when the working conditions and environmental conditions, but can not start the engine, so that future operations would be more able to get the error code, lost an important gap in the information Judge, then before repair of electric motors, should be required to record the first ECU fault code, and then perform other repairs.
2. Ignition switch is connected (on), can be easily removed battery cable
When the ignition (ON) position, regardless of whether the engine is running, you can not remove the batteries or disconnect the fuse cord. Due to sudden power cuts may produce self-induction electromotive force of the coil circuit, which seems very high transient voltage (and sometimes up to ten thousand volts), so that the ECU and sensors related microelectronic devices have been seriously damaged. vgp-bpl2 ,sony vgp-bps2
In addition, with the battery voltage is the same as all other electrical devices, the son, ignition switch to the ON position when they can not be deleted, otherwise the same will produce self-inductance the coil related to EMF and ECU or sensor. These electrical installations include an ignition system, the idle speed stepper motor, ECU programmable read only memory (PROM), fuel injector, air conditioning, and other electromagnetic clutch, and some lines connecting ECU.
3. Unable to remove all battery cable to use the method Clear fault code
For most motors run, remove the battery cable or remove the fuse leading to the ECU to maintain power for 30 seconds, you can erase the error code stored in the ECU. But for some engines, it is not suited to this approach, because the fight against car alarms, audio, quartz, etc. memory (including your anti-theft) are also stored in RAM in memory after the power outage will also be deleted together, which sound phenomena such as the lock code on these engines should be based on the requirements of the maintenance manual methods to clear the error code, and must not remove arbitrarily battery cable. pa3400u-1brs , pa3420u-1brs