ENGINE MANAGEMENT SYSTEM System Sensors Throttle position sensor - Used to relay throttle position information to the ECU. Throttle opening angle is used by the ECU to determine fuelling and ignition requirements for all throttle positions. Manifold Absolute Pressure (MAP) sensor. The MAP sensor provides information to the ECM which is used at shallow throttle angles (very small throttle openings) to provide accurate engine load indications to the ECU. This degree of engine load accuracy allows the ECM to make very small adjustments to fuel and ignition which would otherwise not be possible from throttle angle data alone. Engine coolant temperature sensor - Coolant temperature information, received by the ECU, is used to optimise fuelling at all engine temperatures and to calculate hot and cold start fuelling requirements. Intake air temperature sensor - As the density of the air (and therefore the amount of oxygen available to ignite the fuel) changes with temperature, an intake air temperature sensor is fitted. Changes in air temperature (and therefore air density) are compensated for by adjusting the amount of fuel injected to a level consistent with clean combustion and low emissions. Lambda (Oxygen) Sensor Situated in the exhaust header system, upstream of the catalyst box. At idle and other specified engine speeds the oxygen sensor continuously senses the content of exhaust gases and signals this information to the ECU. According to the signal received, the ECU adjusts the air fuel ratio to within specific parameters thus controlling idle CO and eliminating the need for manual adjustment. Low Level Fuel Sender Mounted on the fuel pump plate or into the tank. The fuel sender detects fuel level and at a pre-determined point relays a signal via the ECU to illuminate the low level fuel warning lamp. Tip Over Switch The fall detection switch will detect if the motorcycle is on its side and will cut the power to the ECU immediately. This prevents the engine from running the fuel pump from delivering fuel. Clutch switch situated near the pivot end of the clutch lever. To enable the engine to start whilst the motorcycle is on its side stand, the clutch level must be pulled in and the transmission be in its neutral position. The engine will start in gear with clutch lever pulled in, providing side stand is in the up position. The ECU will prevent the engine from starting if the bike is in gear, with the clutch pulled in and the side stand is in the down position. Neutral switch situated near the gearbox. The neutral switch indicated when the transmission is in neutral. In addition, the neutral switch provides an interlock facility preventing the rider from riding off with the side stand down. If a gear is selected with the side stand down, the supply to the ECU is removed causing the engine to cut out. Side stand switch - situated at the top of the side stand leg. If the side stand is in the down position, the engine will not run unless the transmission is in neutral.
MAP Pressure MM/Hg SYSTEM ACTUATORS In response to signals received from the sensors, the ECU controls and directs messages to a series of electronic and electro-mechanical actuators. The function and location of the actuators is given below. Idle Speed Control System - which consists of a stepper motor located on the airbox. According to coolant temperature and actual engine speed (in relation to the target idle speed set in the engine management software) Injectors located in the throttle body assembly. The spray pattern of the injectors is fixed but the length of time each injector remains open is variable. The duration of each injection is calculated by the ECU using data received from the various sensors in the system. Main power relay When the ignition is switched on, the main power relay is powered up to provide a stable voltage supply for the ECU Fuel pump - located inside the fuel tank. The electric pump delivers fuel into the fuel system, via a pressure regulator, at a constant 3.5 bar pressure. The pump is run continuously when the engine is operating and is also run briefly when the ignition is first switched on to ensure that 3.5 bar is available to the system as soon as the engine is cranked. Cooling fan - located behind the radiator. The ECU controls switching on and off of the cooling fan in response to a signal received from the coolant temperature sensor. When the coolant temperature rises to a level where the cooling effect of natural airflow is insufficient, the cooling fan is turned on by the ECU. When the coolant temperature falls sufficiently, the ECU turns the cooling fan off. The fan only becomes operational when the engine is running. It will not operate at any other time. Secondary Air Injection Located in the air box area. The secondary air injection solenoid controls air flow through the secondary air injection system, used to achieve cleaner emissions. NOTE: In this system, the starter lockout system (clutch switch, neutral switch, side stand switch) all operate through the engine management ECU. 1100 1000 MAP Sensor Sensitivity 900 800 700 600 500 400 300 200 0 10 20 30 40 50 60 70 80 90 100
Service Bulletin To: From: All Hyosung Dealers Hyosung New Zealand Date: 17 th June 2009 Subject: GT/GV250 and 650 Re-programming E.C.U. Att: All Service Managers and Technicians Below are the re-programming instructions for the 250 and 650 range of motorcycles. Caution Note: To complete the update to the E.C.U. make sure that the battery on the motorcycle is fully charged and the Hyosung diagnostic tool is plugged into mains power. This re-programming process will only take approx. 5 minutes. If in doubt, please connect a battery charger to the motorcycle during this process as low battery voltage during re-programming may cause damage to the E.C.U. Connect the Hyosung diagnostic tool via the diagnostic port which is found under the pillion seat compartment on the GT250/650 and in the front seat compartment in the GV250. Connect both the 2 pin and 4 pin plugs. The Hyosung Motors screen should appear Press the orange Enter button found in the middle of the diagnostic tool within 10 secs. The Initial Screen should now be displayed. Now turn the motorcycle ignition to on. Scroll down to Re-programming on the Initial screen and press the orange enter button Select the correct programme for the bike concerned. Press the orange enter button when you have made your selection. Caution: Before you continue with this step, do not touch the tool or ignition switch during the re-programming stage of the new update. Please read the caution checklist carefully. Program loading please wait will appear momentarily
Bootloader re-programming screen will appear. Press the orange enter button. Do you want to start will appear on the screen Press the yes button on the bottom right of the keypad to continue. This will start re-programming the E.C.U. Firstly you will see initially erase old version until completely erased. Secondly, you will see the update being re-programmed into the E.C.U. When complete, E.C.U. Program Complete will appear on the screen momentarily. Check and press enter will appear on the screen. Press the orange enter button to complete the re-programming process. Switch the motorcycle ignition switch to off and disconnect the Hyosung diagnostic tool from the motorcycle. Start and run the motorcycle to confirm the tune has been updated correctly. Kind Regards, Ken
2010 Hyosung E.F.I. Diagnostic Tool Training