Dongfeng Nissan car fuel pump control system and fault diagnosis Abstract: In this paper, the current Nissan's Teana Sylphy and other cars in the engine fuel injection control system of fuel pump comprehensive analysis and practical guidance from the maintenance point of view At present, Dongfeng Nissan's TEANA, TIIDA, LIVINA, SYLPHY, GENISS, Yi) series models are engine speed control type fuel pump control system.Control system as shown below: First, the fuel pump control system Description First of all, the engine control unit ECM according to the engine speed signal and the battery voltage signal to determine the status of the start signal Second, the engine control unit ECM activates the fuel pump for a few seconds after the ignition switch is turned on from the OFF position to the ON (IG) position to improve the starting performance of the engine.Thirdly, when the engine control unit ECM receives To the crankshaft position sensor (position) and the camshaft position sensor (phase) sent over the engine speed signal to determine the engine is If the ignition switch is in the ON position and no engine speed signal is received, the engine control unit ECM confirms that the engine is stopped. The engine control unit ECM stops the operation of the fuel pump, To prevent battery discharge from the fuel pump, thereby enhancing the safety of the vehicle. It should be noted that: the engine control unit ECM does not directly drive the fuel pump, which controls the fuel pump relay on or off, the fuel pump relay control of the fuel pump Operation: Ignition switch and engine status correspond to fuel pump operation, as shown in fuel pump control system description: Ignition switch and engine status Fuel pump operating status Ignition switch ON from OFF to ON (IG) Stop after 1 second Ignition switch is in ON (IG) or ST range, and cranking of engine crankshaft. Engine stop operation Stop pump oil in 1.5 seconds. Except for the above state, it will not operate Fuel pump control system instruction sheet 2. Description of fuel pump components and control system circuit 1. Components (1) Dongfeng Nissan cars all cars are in the fuel tank using a fuel pump assembly ( Including the fuel level sensor unit and fuel filter.) As shown below: 2. Fuel pump control circuit diagram (original map) Third, the system fault diagnosis 1. Technical reference values, measured between each port and ground NOTE: Do not use the ECM ground port when measuring the input / output voltage as this may cause damage to the ECM transistor Grounding other than the ECM port should be used (1) FPR Item Status Reference Data Fuel Pump relay ignition switch is ON: 1 second after ignition switch is turned on and engine is running 0-1.5V Ignition switch is ON: Engine is not running for more than 1 second after the ignition switch is turned ON (11-14V ) (2) Fuel pump resistance at 25 ° C is approx. 0.2-5 ohms (3) Fuel system pressure The hydraulic pressure at idle is approximately 350 kPa 2. Diagnostic steps Page 6 of 6 Control system block diagram Fuel pump Fuel pump relay Motor control Unit ECM Battery Crankshaft Position Sensor Camshaft Position Sensor IV. Checking Malfunction Parts Check the following: 1. Harness E206, M13IPDM Harness for E / R and ECM is open or short circuit 5. Check capacitor Circuit-I1. Turn off ignition switch. 2. Reconnect all disconnected harness connectors. 3. Disconnect harness connector. 4. Turn ignition switch to ON. 5. Using high-impedance voltmeter, measure capacitor terminals 1 and The voltage between the ground.Normal circumstances: 1 second after the ignition switch is closed, the battery should also have voltage .6 at the same time should check the harness is shorted to the ground or power .In three, check the fuel pump power circuit -I1. Turn off the ignition switch. 2. Disconnect IPDM E / R harness connector E8.3. Turn ignition switch ON .4. Using a high impedance voltmeter, measure the voltage between IPDM E / R port 40 and ground. Normal condition: Battery voltage two , Check fuel pump power circuit -I1. Turn off ignition switch .2. Disconnect ECM harness connector .3. Turn ignition switch ON .4. Using high impedance voltmeter, measure voltage between ECM port 113 and ground. Normal conditions: battery voltage First, check the overall function 1. Turn the ignition switch to the ON position .2 pinch the oil hose with two fingers. Normal condition: 1 second after the ignition switch is turned on, should be on the return hose Can feel the pressure of the fuel beating. This capacitor is only part of the car There are six. Check the 15A fuse 1. Turn off the ignition switch. 2. Disconnect the 15A fuse. 3. Check the 15A fuse. 7. Check the capacitor power circuit-II1. Disconnect the IPDM E / R harness connector E8.2. Check the IPDM E / R between the terminal 39 and the capacitor ground 1. (See the circuit diagram.) Normal should be turned on .3 At the same time should check the harness is shorted to ground or power supply. : 1. Harness connector E11, E2532. Harness connector B202, E1043.IPDM Harness for E / R and capacitor for open or short 9. Check capacitor ground circuit 1. Check harness between terminal 2 of capacitor and ground (See the circuit diagram.) Normal should be turned on .2 at the same time should check the harness is shorted with the power .To check the capacitor 1.Off the ignition switch .2 disconnect the wiring harness connector .3 check the port 1 and 2 between the normal conditions: 11, check the fuel pump power circuit and ground circuit is open and short circuit conditions 1. Turn off the ignition switch .2. Disconnect the "oil level sensor unit and fuel pump" harness connector. 3. Check the "oil level sensor unit and Turn on the harness between port 1 of the fuel pump and port B of harness connector B202, and between port 3 of the "oil level sensor unit and fuel pump" and ground (See circuit diagram.) Normally, it should be turned on. Also check if the harness is short-circuited to ground or to the power supply 12. INSPECT FUEL PUMP 1. Disconnect harness connector from oil level sensor unit and fuel pump 2. Check pressure between oil level sensor unit and fuel pump port 1 and 3 Resistance Normal Conditions Resistance 0.2 - 5.0 [at 25 ° C (77 ° F)] 13. CHECK INTERMITTENT CONDITIONS Check if the connectors in the control circuit are in poor contact. Normal Abnormal System Normal. Checked End Normal Abnormal Abnormal Normal Normal Exceptions 5. Check the capacitor power circuit -I Normal abnormal Replace the fuse abnormal abnormally Repair harness or connector that is open or short-circuit to the power supply. Replace the capacitor normally OK Abnormal Normal Abnormally Repair the open circuit in wiring harness or connector, and the short circuit to ground or power supply. Replace the fuel pump Abnormal Normal Thirteen, check for intermittent failure Second, check the fuel pump power circuit -I Eight, check the faulty parts Repair or replace the harness or connector Abnormal abnormal positive Replace IPDM E / R.
