奔驰W140维修参考.doc

奔驰W140维修参考U1 type equipped with self diagnosis (square) andtest connector (round) the gauge type with squareself diagnostic test connector (round), can be directly read engine fault code: The test joint, however, must be indicated by a closed Angle or a percentage table to be informed of the failure. Error code reading and clearing(1) error code reading and removal method (2) failure code contentThe gauge car, on the side of the engine room firewall, is equipped with a square self-diagnosis seat, which can read the fault code of the engine system circuit・(1) error code reading and removal method 1. Find the self-diagnosis seat・(in the engine room firewall) 2. The ignition switch is ON the ON position. Press the button 2 for 2 to 4 seconds・ Let go of the button, look at the LED (luminous diode) on the diagnostic seat, and read the flash error code・ According to the error code, check the contents of the fault and repair it. After the inspection, read the failure code again to verify that the repair work is complete・ 7. Remove the fault code, need to after the fault code flash, such as 2 seconds, and then press the button more than 6 seco nds, and n ote depending on the diag nosis of seat of LED (light emitting diode), LED light, indicates that the fault code is cleared・(2) the contents of the fault codeFault code content 1 system normal (no fault) section 2 valve fully open switch bad water temperature perceptron 345 bad position sensors in air flow oxygen sensors bad 7 1 cylinder top dead center signal bad (ignition module) 8 bad atmosphericpressure sensors (altitude compensation) nine oil pan adverse verse 10 valve differential pressure valve idle speed switch contact undesirable 12 egr (exhaust gas recirculation) poor temperature sensors (ul 420, 560 cars) 13 engine computer control with dirt or poor contact 16 poor fuel pump fuel pressure less than 17 (fuel pump or hydraulic regulator, etc・ Bad) fault code maintenance application 1 systemnormal description: read the fault code from self diagnosis, LED flash only once, says the engine system circuit is normal, no fault memory. In addition, to clear the memory of the failure code, when the button is pressed for more than 6 seconds, the LED flash once, and the system is normal, the other fault codes are cleared・ 2 fault code (Throttle Valve Switch) content: the section Valve fully open Switch bad description: when the accelerator pedal on the section of the Valve fully open Switch should contact conduction, performed in accordance with the engine computer signal enrichment work・ Test: 1. Ignition switch OFF. Remove the engine connection. Measure computer joint 2 foot (set iron) and 5 foot (full open switch) on the ohm gauge・ When the steam door is in the idle position, the resistance is infinite・ When the pedal is full, the resistance should be 0 ohms・ 6. If the measured resistance change, does not meet the above regulations, shall be directly to valve switch connector test section, section to make sure valve switch inside the bad, bad or external wire・ Coolant Temperature Sensor: the engine，s water Temperature perceptron fails to show that the engine，s Temperature Sensor shorts or breaks, and the engine computer will remember the number 3 error code・ Test: 1. Ignition switch OFF, remove engine connection. Use the ohmmeter to measure the joint 7 foot (common riding loop) and the 21 foot (water temperature sensor)・ 3. Measure theresista nee of the water temperature sen sors specifications are as follows: the temperature resistance of 0 C 5.9KQ10。

C 3.7KQ20C 2. 5 K Q 30 C 1.7KQ40 C 1.2 k Q 50 C 840 Q 60C 600 Q 70 C 435 Q 80 C — 325 Q 90 C 247 Q 100 C Q4・ 190 by 7 and 21 feet feet,unable to measure the resistance, should be directly measuring the resistance of the temperature sensors, so as to avoid external wire break or short circuit, causing malfunction cause misjudgment・ 4 fault code (Airflow Sensor Position Indicator) content: the perceptron bad air flow plate Position description: air flow plate Position sensors is a potentiometer type, it made by the engine computer 18 feet 5 v voltage, back to 7 feet together take iron loop, when the air flow plate movement, the change of volt age signal, that is, from 17 feet input voltage signal into computer・ If the circuit is defective, there is a memory of no. 4. Test: 1. Start engine, keep idle, and wait to get to work temperature・ Use a voltmeter to measure the position sensor of the air flow pane 1. 3. The power of the air flow plate perceptron (blue green line) and set the iron back to terminal (brown white or brown line), the voltage between about 4. 5 〜 5. 5 V range・ 4. To measure the air flow plate position signal (black line) and set iron route back end (brown white or brown line), its voltage in idle speed, should be in the range from 0. 5 V to 1. 5 V. Turn OFF the ignition when the voltage is not in conformity with the specification. Remove the air f 1 ow。