Britprius

For the best fuel economy you should use a 0w20 synthetic oil. However the make of the oil is not rely a problem. In the hand book it will give a minimum specification for the oil, such as API SL, SM, or ILSAC, and as long as the oil you have meets or exceeds that specification it will be fine to use. If your oil level on the dipstick is at the low mark or below any engine oil is better than no oil. John.

Shifting to neutral before braking forces the use of the normal brakes since the regen cannot work in neutral. This method is also kinder to the tyres as you can use the brakes over a longer period while descending a hill. Going back into drive while still moving is not problematic or harmful. John.

Hi Mark. If you look at my fuel consumption figures you will find they are very much in line with those of members "Farqui" and "Royoftherovers". The so called CVT gearbox is actually an ECVT, and is nothing like a normal CVT or torque converter transmission. If you Google Eahart prius PSD and scroll down on the page there is a working depiction of the basic system. You can move the sliders on screen to see how varying engine speed, and or electric motor speed how the system works with details of road speed, engine revs, and the two motor generators speed, and direction. It also shows how reverse is accomplished. From this you will see just how simple the system is in reality. There being no gear ratio or direction changes of any sort even for reverse or neutral. The GS does have one ratio change for one of the electric motors that occurs at about 60 mph. This is to reduce the speed of the motor to increase it's torque. Electric motors "of the type used" generally have very high torque at low revs the opposite to internal combustion engines. John.

The previous owner details no longer appears on the V5, and has not done for at leased 3 years. John.

Leave the car on the charger for at leased 24 hours or even more if it's charge rate is below 5 amps. The battery will be of at leased 70 amp hours capacity, and the charge efficiency is only about 60%. This means at a constant 5 amp charge rate the battery would need to be on charge for 14 hours plus 40%. Another 6 hours. Unfortunately lead acid battery charge acceptance falls dramatically as it's level gets above 80%, and many chargers although rated at 4 amps only charge at half of that rate. Using the cars alternator to compensate is asking for early retirement of it. John.

Hi Mark. Welcome to LOC. I would expect mid to high 30s on a motorway run, but at 75 to 90 your not pushing it in any way. I drive twisty country roads with some zest, lots of. accelerating and braking returning the mid 30s. The lowest tank full ever was 32 mpg. I would not be concerned with the battery. The shocks are prone to leeking at around 250 each if you fit them yourself. Not difficult as a spring compressor is not required The exhaust is prone tto failure at the rear Y pice. The rear section is around 850 complete about 1250. A purpose made stainless system is the way to go. John

Andy I am happy you got it sorted. As you now know jumping a hybrid can be very problematic, and should be avoided if at all possible. The problem is a flat 12 volt battery always happens when your in a rush, and it's throwing it down with rain. Not the best time to be giving 100% concentration on what you are doing. I do not believe anyone who say's they have jump started many vehicles, and never got it wrong. Have a happy new year. John.

The charging system on the Toyota/Lexus hybrids is a very capable system. It is capable of over 100 amps output to run the accessories and charge the 12 volt battery. Unfortunately the OEM battery does not respond well to being deep discharged, and seems to loose much of it's capacity as it ages. This is the reason I did a post on fitting a higher capacity battery to the GS450H. I do not know if there is room in the GS300H to fit a larger battery, but I would suggest you look into the possibility. I fitted a 110 AH battery in place of the 70 AH OEM battery. High cranking amps is not a requirement in a hybrid since the battery is not used for turning over the engine, but a higher AH capacity is desirable. Never use the car in ready mode, and neutral as in this mode the engine cannot start. Any other gear position is ok. The HV battery will still be left to run the AC, accessories, and charge the 12 volt battery. When the HV battery gets discharged it cannot charge the 12 volt battery, and if the HV battery gets low enough on charge it will not start the engine meaning a transporter to the dealers for charging. John.

I have yet to find anything for Toyota/Lexus vehicles that was correctly specified by Kwick Fitt or Halfords. On checking with both companies for oil, plugs, and 12 volt batteries for my Prius, and Lexus GS I was given the wrong information on all three products for both vehicles. John.

Start by tilting the mirror up as high as it will go. Then pull the glass outwards and upwards with as many fingers as you can. Once released from it's bottom clips it can be unhooked from the top clips. The holding screws for the casing will now be visible. It helps to warm behind the glass with a hair dryer to soften the plastic holding clips before attempting to pull. John.

Definitely not normal. It should be just perceptible, and should be returned to the dealer as presumably the car is still under guarantee. John.

I have a GS450H, and this also exhibits the same symptoms as you describe to the point of being unnerving at times. I once had a Mazda 626, and this had a three position switch on the cruise ECU under the passengers seat to choose the level of response. It also had a similar function on the hydraulic power steering ECU to adjust the level of power assist. This is something I would like on the GS to reduce the amount of PS assist. John.

Try this. autocats.ws/manual/lexus/gs450h/rm02e1ru/ewd/index.html And chose Hybid system.

Did you check the voltage of the modules under load? If not they are meaning less. Both filaments of a standard headlamp bulb (HB4) is ideal giving a load of about 10 amps. There is no ground on the HV side of the battery it is left floating. Grounding one side will throw a fault code. You symptoms sound like a fuse or the HV battery link not installed correctly. Can you read a circuit diagram? If so I will try and supply one. John.

David. The two units will almost certainly be. The high voltage ECU this checks the voltage (around 14.4 volts) of each pair of modules (blocks) against all the other blocks to check if they are out of balance. It also checks current in, and out, and controls the minimum, and maximum charge level (40% to 80%). It also checks the battery temperature indirectly running the cooling fan. The other is the system main relay box that connects the battery to the car in ready mode it also houses the current sensor. There is no way apart from checking the condition of the plug and socket pins to test the HV ECU. The The system main relays can be unplugged, and tested in the normal way, but these are very robust high voltage high current units that rarely fail. Perhaps you can describe more fully the symptoms you have with the car as I believe you problems are else ware. A list of what works, and what does not would help. John

Was the display showing electricity going back into the battery on over run? and was the battery display going up, and down in the number of charge bars shown? while being driven. John.

Without the fault codes it is difficult to give any reason for the warnings. I can say that the reason for the brakes being hot is most likely due to the fact that regen braking is not working due to the hybrid fault. Regen braking is normally used to slow the car producing electricity to put back into the high voltage battery. This means the mechanical brake system has to work harder than it normally would. The problem could be something simple, but be prepared for Lexus to charge £100 or more just for diagnostics. It is worthwhile to invest for the future in a Mini VCI with an old laptop to be able to do your own diagnostics available on the Bay for around £20. A low 12 volt battery at start up can give rise to many false problems, but these disappear once the car has been started, and the battery gains charge. John.

A true spoil sport. Wheres your Christmas spirit? I drank all mine yesterday. John.

It's obvious I was not in your area over Christmas. There would definitely be no mince pies left. Happy Christmas everyone, and a happy new year. John.

My worst car was a Vauxhal Victor 101. This car possibly had the softest suspension of any car including the Citroen 2CV. On a strait road the ride was very smooth but cornering there was so much body roll, and you had to hang on to the steering wheel to stop you sliding along the front bench seat covered in a shiny plastic material. The bodywork dissolved while you watched in the rain. The best car for performance, and comfort without doubt is my GS450H, In reliability, and economy terms as in the post above over 10 years, and 140,000 miles my Prius gen2 Tspirit wins hands down. The only item replaced in that time was a NSF wheel bearing getting noisy due to pothole damage. John.

The high voltage link between the modules 20, and twenty one (cells 120 and 121) has a fuse built into it. It also has another pair of contacts that are not made until the refitting procedure is completed. After closing the lever the link must be slid up or down or side ways "depending on the links orientation" to close these contacts completing a 12 volt circuit. The modules in the pack have a nominal voltage of 7.2 V, "6 cells" and are arranged in pairs for monitoring purposes called blocks The battery has a nominal voltage of 288 volts. Individual cells cannot be monitored or connected to being totally sealed in the modules in much the same way as cells in a modern 12 volt car battery. There is a 140 amp fuse in the 12 volt positive battery terminal as well. There are a number of fuses that if blown will not allow a state of ready in the other 12 volt circuits. This is common if the car has been connected in reverse polarity. There are fuses in the main fuse box under the bonnet as well as in the two front foot wells, and also above the 12 volt battery in the boot. There are two fuses at the positive terminal a low current, and a high current fuse. There will be no output on the pack terminals as there are three high voltage DC relays in the pack that do not connect until the car is in ready mode unless you are connecting your meter before these relays at the battery terminals. There will be high voltage at the battery terminals as long as the safety link is fitted with the lever closed, and it's fuse is intact, but not slid in the required direction to complete the low voltage circuits John.

But you can have a many health checks a year as you need and are free with each 10,000 mile service. This means unlimited millage guarantee until the car is ten years old. John.

The figures you quote sound about normal to me. My previous car a Prius on witch the CT is based varied by around 10 mpg from summer to winter. The Prius however returned about 55 mpg winter, and 65 mpg summer. There were some occasions in the summer when I achieved 72 mpg per tank giving a range of over 700 miles. John.

This has not been mentioned before. Are you asking why there is no 12 volt feed at the OBD port? John.

If you have a laptop the best system yo use is Techstream with a Mini VCI around £20 on the bay. This gives you the same sort of level as the dealer. John.