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Mihanicos last won the day on July 31 2019

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    GS 450H
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  1. Hi, Thank you very much for the update and all the information regarding the problem. It is reassuring to see that the electronics of this car are very reliable and can withstand the wear and tear. Kindest regards, Chris.
  2. Hi, P0868 894, refers to the difference between the value of the transmission revolution sensor rotational speed times the gear ratio of the 2nd stage motor speed reduction planetary gear unit and the MG2 rotational speed, exceeding a specific value continuously for a specified time at a speed of 22 mph or more. Before touching anything on the inverter converter and any high voltage equipment, remove the HV plug from the trunk and wait 10 minutes for the capacitors to discharge. Wear insulated gloves and measure the voltage present on the equipment you are about to touch. The problem could be at the wire harness or connectors of all relative equipment, Hybrid vehicle transmission assembly, oil pump with motor pump assembly, hybrid control ECU, Fusible Link and the oil pump relay. Check the hybrid ECU connector. Check for corrosion, dirt and anything that makes a bad contact. Oil pump motor controller connector. Check hybrid transmission SL1, SL2 solenoid valves and Solenoid valve connectors Transmission rev. sensor connector pin 1 and ground, 11 to 15 Ohms at 20C SL1 connector pin 3 and pin 2 , 5 to 5.6 Ohms at 20C SL2 '' '' 22 '' '' 21, '' '' '' '' '' '' In engine bay, check the fusible link of the oil pump. Check the oil pump relay resistance values. Pins 1 and 2 , 151 to 203 Ohms. Pins 3 and 5, 10 KOhms or more. With 12v across pins 1 and 2, resistance between pins 3 and 5 shoul be less than 1 Ohm. Check the harness and connector between HV control ECU and oil pump motor controller. There are measurements to take on the connectors which I will try to leave on another post if you want to pursue the issue further. P2797-865 , refers to the auxiliary transmission fluid pump control performance.The oil pump motor controller, controls the rotation speed of the oil pump motor [ 3 phase brushless motor ] in accordance with the rotation speed request signal sent from the hybrid control ECU. The controller also displays the oil pump motor status as a signal to the hybrid control ECU. To diagnose what is causing this DTC involves a lot of measurements and I will try to send them to you if you have the time to go through the tests. They are measurements on the connectors on the equipment involved. Concluding, make sure that the 12v battery is ok and it never falls below 11volts. Make certain that the ground points are good and without resistance between the battery negative terminal and the ground point in question. Male sure that all connectors are clean, corrosion free and sealed from rain, moisture, dirt and dust. make sure that they fit firmly and securely. Pay particular attention to the pins of the connectors, clean them if necessary with suitable solvents for electronic electronic equipment. Check for damaged harnesses and repair. Kindest regards, Chris.
  3. I have been doing some research on the Internet about Inverter applications for cars. Researchgate.net and Freescale have some papers on high temperature electronics, such as Insulated Gate BipolarTransistor [ IGBT ] modules for electric and hybrid vehicles. As far as I could make, IGBT are used in conjunction with other semiconductors and the operating temperature limit of their circuits is 150C mainly due to solder considerations. Research is going on to improve the operating temperatures.
  4. Hi, In some Lexus owner's manuals it is stated that the transmission fluid is for life. However if you look up the information in the repair manual of the same model in Lexus-tech.eu you will find a specified interval in years or miles whichever comes first. Some models now specify in the owner's manual a transmission fluid change every 4 years or 60 000 miles whichever comes first [ RX 450H 2015 ]. Your car should be the frame UZS 161, engine type 3UZFE, RHD, destination Europe, from July 2000 to January 2005. It has an oil dipstick for the transmission fluid and changing the transmission fluid should an easy and straight forward job. I would change the transmission fluid without delay. I have always changed the transmission fluids of all my cars to date every 30 000 miles or 5 years whichever comes first, for normal driving conditions in the region where I live. Kindest regards, Chris.
  5. Hi, I agree, inverters do generate a lot of heat instantly and the coolant should be able to absorb it. Upon further reflection, may be the coolant is not circulating fast enough to remove the heat from the inverters. At the same time, the engine and the inverters share the same cooling system, and if the engine has developed gas blow by from the combustion chambers due to piston wear, this would contribute to more heat added to the coolant. Gas blow by is more intense under hard and severe acceleration. You can check this by removing the engine oil filler cap momentarily and see if there are any gases coming out. Engine oil consumption is another indication. Beware of oil coming out usually from a nearby camshaft. However, this heat from gas blow by should not cause an immediate coolant temperature rise as that due to inverter heat generation. Whenever the cooling system is opened for any repairs, replacements, you must make sure the heater is fully on and bleed the air from the heater radiator by squeezing the flow hose into the heater radiator while the engine is running, with the engine thermostat open and the radiator cap off. As you squeeze the hose the coolant level in the radiator should fluctuate. keep doing so until the coolant level changes to the slightest squeeze on the heater hose. Any trapped air in the heater radiator will compromise the coolant flow and this will hinder efficient coolant flow. Another point to consider is the water pump impeller being worn out, a very remote possibility but I have seen some cases totally unbelievable. As long as the expansion tank has coolant in it, any air in the tube from the radiator to it should bleed out. The volume of the coolant when it expands is more than the internal volume of the tube from the radiator to the expansion tank. Check the water temperature sensor by immersing it in water and reading its resistance. At 20C, the resistance between its terminals should be 2.32 to 2.59 K Ohms. At 80C " " " " " 310 to 326 Ohms. Replace the sensor if the readings are not within specified range. Chris.
  6. Coolant replacement is at 100,000 miles irrespective of time, please accept my apologies for my mistake. Make sure that you have no leaks at all because this would reduce the system operating pressure and this in turn would lower the boiling point of the coolant. Once the coolant boils within the system, more coolant will be released from the radiator cap leading to less mass of coolant which in turn raises its temperature causing further boiling. At standard atmospheric pressure pure water boils at 100C. Chris.
  7. Hi, From the data of the engine active test, the coolant temperature range is between -40C and 140C. Normal range is between 80C and 105C after warm up. A note about the temperature sensor states that if the displayed temperature is 140C, then the sensor is short circuited. If it displays -40C, then it is open circuited. It may be worth checking the sensor although from your description it seems to be ok. Sometimes a short circuit occurs at higher temperatures than normal. Another point to consider which is critical, is the radiator cap, and if it opens at a lower than specified pressure, this leads to coolant boiling at a lower temperature. If this happens, then the rate of heat rejected through the radiator is reduced proportionally. Hence a rise in the coolant temperature. I would suggest that you check the inverter cap and make sure it is within specifications. [ Range : 15 Kpa to 44Kpa ] Minimum 12 Kpa. If it opens at a lower pressure, replace the radiator cap. Check that its vacuum valve is not stuck and free to move. Also make certain that everything is clean a free from any rust deposits. The coolant should changed initially at 100, 000 miles or 10 years of life whichever comes first. I hope the foregoing will be of help to you. Chris.
  8. Hi, The freeze data gives you three sets of readings before the DTC, one set of readings when the DTC was set and one set of readings after the DTC was set. These data are given in 0.5 seconds intervals. Since the DTC refers to the fuel pressure high side, the readings you have refer to the fuel pressure high side. Using the Techstream, alter the fuel target pressure and observe that the fuel pressure fluctuates. you can lower the target pressure by 12.5% and increase it by 25%. If the pressure changes by the exact amount, then you may have a faulty ECM. If there is no change, then you must check the fuel relief valve and its relay. During these tests you have to put the engine on inspection mode. Put the gearbox on P. Press twice the accelerator fully. Move lever to N and press accelerator fully twice. Move the lever to P and press the brake pedal and the start button simultaneously. The engine should start and you can vary the engine rpm up to 2500. Always start with the easy tests and with the cheap replacements. Good luck. Chris.
  9. The DTC occurs when the fuel pressure on the high pressure side is too low. Fuel pressure is achieved by a mechanical pump driven by a camshaft and is regulated by the spill control valve. A fuel pressure sensor monitors the pressure and is regulated between 4 and 13 MPa. If the pressure is lower, the ECU closes the spill control valve. If the pressure continues to drop, the ECU blocks the power to the spill control valve so it remains open and regulates the engine to a max of 2000 rpm. Check for fuel leaks on all pipes of the fuel system after the high pressure pump. [ Fuel pipes to direct and indirect injection injectors. Fuel injectors leaking.] ] Fuel pressure relief valve. Fuel relief valve relay. Fuel pressure sensor. Fuel pump for high pressure. To carry out some tests you will need the techstream. Kindest regards, Chris.
  10. Intermittent noises and vibrations are very difficult to locate and eliminate. Try raising the car on a lift jack or on stands and put the engine on inspection mode whereby the engine runs continuously and you can vary the rpm with the accelerator. If the symptoms occur under no load, you should be able to pinpoint what you are looking for. For a GS 450H , the inspection mode is achieved as follows: 1. Turn the power switch ON (IG) . 2. Move the shift lever to P and then depress the accelerator pedal fully twice. [ If the shift lever is already at P position, just press the accelerator pedal twice ] 3.Move the shift lever to N position and press the accelerator pedal twice. 4. Move the shift lever to P position and press the accelerator pedal fully twice. 5. Check that " maintenance mode " is displayed. 6. Turn the power switch ON ( READY) and the engine should start. 7. To deactivate the inspection mode, turn the power switch OFF. Wishing you the best of luck, Chris.
  11. My car has also a " sealed for life " gearbox, as stated in the owner's manual. However in the maintenance schedule of the repair manual of Lexus published by Toyota-Lexus [ Lexus-tech.eu ], for my car, it is stated that every six years or 72 000 miles ( I am not quite sure of the mileage but it is somewhere around there ) the transmission oil should be changed. Log into Lexus-tech.eu and you will find there all the information you need.
  12. When new, my car used to do 43 miles to the gallon. As the years went by, this figure kept going down and by coincidence when a maintenance item was carried out according to the maintenance service schedule. eventually it dropped to 40.4 miles to the gallon and two months ago, I used to get " check VGRS system " and the car would not start on the first time. I used the techstream and no trouble codes were present and the VGRS system was ok. However there was a message that the 12v battery was low with only 10 volts. I charged the battery to the full and the car started without any codes. It run for a few minutes and the engine stopped, normal behaviour. After a few minutes , the engine started again and it should not have done since the car was stationary in the garage. This only meant that the 12v battery needed to be charged. A check on the battery revealed 10 volts. I had the battery checked and it was not up to specification. I put a new 80Ah ordinary battery and not the original Panasonic and the car now does 42.5 miles to the gallon. I was convinced that the hybrid battery was in need of maintenance and I was planning to do so in a couple of months when the weather improves. I never thought that a bad 12v battery would make so much difference in the fuel economy. Chris.
  13. You will find all the information you need in Lexus-tech.doc. It costs about 6 Euro per hour of looking up repair, maintenance and scheduled service information. You can also print anything you want. I have already changed the ecvt transmission oil in my car according to the maintenance schedule.
  14. You must check the power battery voltage, it should be about 300 volts dc. If not, you probably have an open circuit somewhere along the series connections on one or more individual cells of the battery. Check that all your connections are correct and good. If you have access to a Techstream or a similar scanner it would be a great help. Chris.
  15. Make sure that the 12v battery is fully charged. Regards, Chris