Fault description: a 2004 sedan FIT owners described the car in the way the engine suddenly turned off, no longer start. According to the owner of the car did not carry out any maintenance.
    Inspection process: According to the use of the car to consider, only travel more than 10,000 km, should not have a big problem. Open the ignition switch, the light all normal, turn the ignition switch to start the engine, the starter is strong and the speed is enough, but the engine does not start. From the first simple and complex ideas to start the first check the oil. The car engine is a program to control the fuel injection system, the fuel pump is controlled by the computer. Turn on the ignition switch for 2s and stop working after the engine starts. So repeatedly turn the ignition switch, open 2s off and then open 2s off. Open the fuel tank to listen to the work of the fuel pump and found the fuel pump has started hissing, open the engine compartment to open the fuel into the tubing with fuel pump, the initial proof of normal oil.
    Next look at the circuit, the car ignition system using Honda's latest I-DSI (intelligent independent double ignition), each cylinder has two ignition coil and spark plug. Remove the first and second cylinder of the front ignition coil and the spark plug found that the spark plug has a very wet petrol liquid, the spark plug into the ignition coil on the cylinder head on the ground, start the engine spark plug no spark sparks, indicating the ignition system is faulty. Unplug the three-wire plug of the ignition coil, the three lines of color were black / yellow (power line), white (computer control loop), black (ground line). Open the ignition switch, first with a multimeter to measure the black / yellow (power cord) should be the battery voltage, the results no voltage. According to the circuit diagram found in the driver's side of the fuse box 14,15 fuse blown, 14 for the front ignition coil insurance, 15 for the rear ignition coil insurance. Replace the new fuse and turn on the ignition immediately after the ignition, it is clear that the ignition system has a short circuit. With a multimeter to measure the insurance box within the 14th, 15th fuse outlet to find the power to ground short circuit, find the line all normal. When all the ignition coil plug is unplugged, it is found that the short circuit of the fuse outlet disappears. So the eight (the first four, after four) ignition coil one by one to remove the measurement, the results found before and after the two-cylinder ignition coil are internal short circuit.
    That the problem finally found, replace the two before and after the ignition coil, replace all the lines and fuses to start the engine, the engine still can not start. At this time the engine speed is not enough, the battery power has been significantly reduced to the battery fully charged after the start of the engine, the engine has sudden, sudden sound, it seems to start the meaning, but still can not start.
    Failure analysis: in the case of oil can not start fire, only consider the mechanical and control system. The car engine timing using advanced quiet chain, and only ran more than 10,000 km estimated problem is not big. Honda dedicated HDS diagnostic system into the vehicle computer, the results did not find the fault code. View the data flow, the signal is normal. Start the engine accidentally found the engine speed is only 60r / min, obviously not normal. The engine speed signal is obtained by the crankshaft position sensor, so remove the crankshaft position sensor to measure its resistance, then accidentally found the sensor end (with the crankshaft trigger wheel to obtain the signal part) has a very obvious wear and tear. Crankshaft position sensor is electromagnetic induction, through the crankshaft trigger wheel rotation to get the engine speed, under normal circumstances it has a certain trigger with the crankshaft clearance, should not wear. So that the trigger wheel has a problem, ready to remove the oil pan check. When the vehicle was raised, it was found that the sump had collided and the oil pan was removed and collapsed after the collision (the car was covered with an aluminum engine and an oil pan). So we removed the oil pan and found the crankshaft trigger wheel has been split into three, of which two have been dropped in the oil pan, leaving a small part of the trigger wheel can only give the sensor very low engine speed Signal, causing the engine to sudden but can not start.
    Maintenance program: change the trigger engine after a one-time start successful, with HDS into the computer system to view the data flow all normal, troubleshooting to this rule.