a 2003 annual car Chery Eastar 2.4 L, equipped F4A42 type 4-speed automatic transmission, the user will reflect the commit break significantly when the vehicle traveling at 40 ~ 60 km / h acceleration and deceleration.
After receiving the vehicle, as determined by the user of the fault test. The fault symptom car, maintenance experience combined with the author, the reason for this failure is generally caused by an ignition system comprising a failure, the electronic control system-related sensor signals unreasonable, poor working engine control unit and the automatic transmission control system failure. Before treatment failure, we had to communicate to the user and the user is reflected in the car after the failure of the above other repair shop clean the throttle and injectors. Later, in another service station replaced the spark plugs, high voltage, ignition coils and fuel pumps, but the fault has not been able to solve.
is connected to the engine control system fault diagnostic checks, no fault code display device, but the data stream when reading found, a throttle position sensor signal voltage at idle is 176 mV, the voltage should be in a standard 600 mV or so. Using a fault diagnostic apparatus for the automatic transmission control system is detected, the device displays ldquo; 14mdash; mdash; throttle position sensor is abnormal adjustment rdquo; fault code. According to reflect the user’s service, in conjunction with detection of the failure diagnostic apparatus, the author determines that maintenance personnel repair shop related to artificially adjust the initial position of the throttle position sensor when the throttle body cleaning. Therefore, according to the original method of operating the service manual re-adjustment of the relative position of the throttle position sensor.
to adjust the following steps.
① fault diagnostic apparatus connected to the diagnostic interface;
② a thickness of 0.45 mm is inserted into a gap between the regulation and the throttle lever fixed SAS;
③ ignition switch oN;
④ mounting bolt release throttle position sensor, a throttle position sensor and the counter-clockwise direction in the end;
⑤ in this state, diagnostic or multimeter to check whether the idle position switch in the oN position;
⑥ slowly rotating clockwise throttle position sensor, taking into account the idle position by the switching signal
Stop ON to OFF
, a throttle position sensor locked in this position fixing bolt; output voltage
⑦ check throttle position sensor, the standard value of 400 ~ 1 000 mV;
⑧ If the deviation from the standard value, check the throttle position sensor and related wiring harness;
⑨ remove regulatory clearance, the ignition switch is turned off, the open malfunction diagnostic apparatus.
After the adjustment of the correct throttle position sensor adjustment method, test troubleshooting.
Summary: This is one case of a typical human error, for adjusting the initial position of Mitsubishi engine throttle position sensor, the procedure is more complicated. General comprehensive repair shop because there is no relevant information and special tools, it is difficult to adjust the throttle position sensor to the appropriate location. The reason why the vehicle will be reflected in the user failure, because the initial position of the throttle position sensor is changed, resulting in the automatic transmission control unit receives a throttle position error signal, thereby altering the correct shift points, resulting in a transmission shift rude, the shift time does not match the current vehicle speed.
(Qin Zhigang, Akihiro solution)