Failure phenomenon: a 2007 annual POLO strong feelings 1.6 L sedan, mileage 56000 km. Users reflect the car starter is operating normally, but the engine can not be started.
Check Analysis: I take the car, first test to verify the failure phenomenon, turn the ignition switch, the light indicator can be seen working on the instrument were normal. Try turning the ignition key to start the vehicle, the starter can normally drive the rotation of the engine, but the engine is not the sign of the car. Use of the vehicle fault diagnostic testing and found that the fault memory is a plurality of fault codes, including low battery voltage, the open circuit injector N30 ~ N33, N80 canister solenoid valve is open, and so multi-cylinder misfire. Because it has been carried out before the car repair shop in other maintenance, in order to rule out when maintenance may cause false fault records, after I clear the fault record to start the vehicle, the engine still can not start, then use a scan tool to read again the fault recording, the fault code appearing again.
The author begins with the ignition system is checked, the cylinder 1 is first pulled out of the ignition coil, a spark plug is inserted in the ignition coil, a flashover experiments and found that spark plugs do not flash over, the second cylinder checked by the same method the ignition coil, the same can not flash over. Then, the respective connector pin 4 disconnect the ignition coil, where each of the test power supply terminal of an ignition coil with a test lamp, did not find electricity.
The fault code analysis, the car should not only be the fault does not flash over due to ignition coil, injector 4 may not injection. In order to verify their own ideas, I turn the ignition switch, the lamp used for each test the injector power supply terminal plug was tested, it was found that the injector common power supply line is not electrically.
FIG 1
Through the above diagnosis, my analysis, fault diagnostic use may normally enter the engine control unit, and perform various operations, so there is a possibility of the engine control unit fault is small, should a fault in the ignition coil and the injector line. Related circuit diagram (FIG. 1), and found that 4 of the ignition coil is through the power injector, and SB25, respectively, by the fuse (fuse injector) and SB37 is (fuse ignition coil) provided in the main supply relay J271 provide protection. When the ignition switch is turned on, the engine control unit nWork properly, i.e. will pull J271, it is powered by its management appliance. Could it be that there is a fault relay J271? So I turn the ignition switch, and power supply to check the situation SB37 SB25 fuse with each test lamp, test normal lighting, and can hear the sound of the relay pull J271, described is relay is normal, the fuse should be the point of failure after the line. Carefully check the relevant line, discovered by J271 access to the engine compartment power injector and an ignition coil line, subject to the middle of the compact modular plug connector T6r inner middle and the left suspension firewall T14. So I checked these two plugs, plug T14 has been found loose outside the plug bayonet and not stuck. The tight plug, the ignition switch is opened again, this time to check the power supply of the ignition coil case 1 cylinder, we found normal power supply, and then start the engine, the car smoothly.
Troubleshooting: T14 plug seated and chucked troubleshooting.
(LI Jun-hui)