Britprius

There are other problems with Lexus/Toyota hybrid transmissions that do not apply to other vehicles. The transmission oil is in direct contact with the two motor generator electric windings. These windings carry a high voltage "around 700 volts depending on the model". Only lubricants that have been tested for there dielectric properties "insulation" should be used in these systems. The oil is used for lubrication, cooling, and insulation. The oil in use is put through heat cycles, and also possible dieseling as well as metal particle contamination leading to acid build up in the oil. This reduces the dielectric strength of the oil "it's ability to act as an insulator". This can lead to failure of the motors due to shorted windings. The reason high voltage power grid transformers have there oils tested, and changed at regular intervals even though no mechanical stress is put on the oil. On the US Prius Chat forum many have had the transmission oil analysed at various millage's. The findings were that the oil was badly contaminated and had a substantial drop in viscosity by 30,000 miles. After that initial run in period 60,000 miles intervals seemed the ideal change point. The Prius shares it's engine, and drive train with the Lexus CT. I would always change the transmission oil in Toyota/Lexus hybrids along similar lines where possible. An oil change is cheap insurance against problems. John.

Adjust the rod at the top by slackening the nut on the back of the ball joint and slide it downwards in the slot on the rotary mechanism.. Try about 1/4 inch movement to start with. See picture below. John.

The quick and easy way to adjust the dip beam is to adjust the position of the link on the front N/S suspension. This can be got at with the wheels turned to full lefthand lock, and requires a 10mm spanner to slacken the adjuster nut. John.

The switch also alters the steering ratio for a quicker response to steering input. John.

As Lee says there is room to work on the heat shield. Removing the two rubber hangers rear of the silencers will allow them to drop to give more clearance. The OEM nuts "8 mm socket size" holding the shield are made of a very soft material "probably zinc", and may break up or round off as you undo them. Replace them with steel nuts and a good coating of copperslip anti seize compound along with some penny washers for a lasting job. John

The relay does exist, but as I said previously it is a solid state relay. It does not make sense for it to be any distance away from the other two relays, and may even be integrated. This would show as possibly up to three extra contacts on one of the other two relays. John

That is correct. I also have a Block from an RX450H that also has three normal HV DC contactors. The block diagram shows three contactors, and the only other information for position is below. John.

Unfortunately I cannot help with the exact location. It may be built in to one of the other relays. On other Toyota/Lexus systems I have dealt with it is a separate relay, but the only information I have that shows this relay shows it as a solid state "transistor" relay. Although this type of relay has no moving contacts the switching transistor can go short circuit. See the block diagram of the circuit below. The relay you are interested in on the diagram is below the words "Hybrid vehicle converter" This is the SMRP relay You will see that when the transistor conducts it passes battery current through a resistor to the boost converter. When relay SMRG contacts close all the current goes through those contacts as they short circuit relay SMRP I hope this is of help. John

More than sensible if your not sure what your doing. John

This is a power supply unit usually mounted in the bottom of the headlamp that produces from the car battery 12 volt supply around 25,000 volts to strike an ark inside the HID (high intensity discharge) bulb "rather like a spark plug". Once this ark is established the gasses in the bulb become ironised, and conduct electricity, and the voltage required to keep the bulb alight drops to around 80 volts for D4 bulbs, and around half that for D2 bulbs. The ballast can give you a rely nasty electric shock that can even be lethal particularly if no bulb is in circuit whilst turned on. A voltage of 25,000 can jump an inch gap so you do not even have to touch the wire to get a shock. John

There are three contactors (relays) inside the HV battery. One connects the negative supply the second connects the positive supply. The third relay is the precharge contactor. The order of operation for the contactors is the negative and precharge contactors come in first supplying current to the inverter. The precharge contactor connects the supply through a resistor to stop high inrush currents from the battery. After a second or so the positive contactor comes in missing out the resistor to allow full battery current. The fault code POAE2 suggests that the precharge contactor contacts are stuck closed "they sometimes weld themselves together". You can check the contactor with your ohm meter to see that the contacts are open until 12 volts is applied across the coil. If the contacts show closed circuit at all times they are stuck. If this is the case you may be able to open the contactor and prize them apart to get you going, but it will need replacing. John

All lead acid batteries use the same basic construction, and chemistry. There are three basic versions however. (1) The flooded lead acid battery "or normal car battery" uses lead paste based plates immersed in dilute sulphuric acid. These generally, but not always can be topped up with distilled water as this is gassed off in the form of hydrogen, and oxygen while the battery is being charged. (2) The AGM (absorbed glass mat) battery. Uses thinner plates than the flooded battery, and the acid is held in 95% saturated glass fiber mats between the plates. There being no free acid to spill if the case is broken. The cells are sealed with pressure releaf valves. When being charged some pressure is built up in the cells by the same gasses as in the flooded battery, but these gasses are turned back into water by a catalyst in the top of the cell, and returned to the plates. The maximum charge rate is usually lower than flooded batteries, but the life span is usually greater even with higher depths of discharge. These batteries are often used in hybrids "often in the cabin area hence the vent tube just in case the battery is over charged." where they are not used for engine starting, and the charge rates can be better controlled there being no alternator. They are also widely used in medical equipment, mobility scooters, wheel chairs, reclining chairs, and stair lifts where the release of hydrogen gas "explosive", and spilling of acid could be dangerous. (3)The gel battery has similar build to the AGM battery, but uses the acid in a gel form. This restricts the charge rate even more keeping it below the level of forming gasses. If gasses are produced by being charged to fast they cannot rise through the gel, and reduce the area of plate in contact with it permanently. This reduces the capacity of the cell. This type battery used correctly has the longest life span The AGM and gel versions have slightly higher charging and output voltages " 13.8 to 14.2 volts compared with flooded batteries 13.6 to 14 volts. John.

D2S bulbs run slightly brighter than D4S, but the real bonus is that D2S are also available in a 55watt version giving even more light, but the correct beam pattern against the 35 watts of D4S. The downside is that you must also change the ballasts to ones suitable for D2S bulbs as the running voltages are different. John.

POAC2 is the main HV battery current sensor. This appears to be giving a reading of -200 amps, and since the HV contactors are not operating this reading cannot be true it should be zero. The contactors can be checked by removing them and connecting a 12 volt supply across the the coil connections. There should be a loud click,and the other two connections should now be joined (zero ohms). If any critical code is still showing the contactors will not pull in to supply the high voltage to get to ready and start Battery block (4) modules 7&8 locks low at only 14.2 volts where all the rest are around 15.6 volts. This will likely cause problems once you have the car running. Have you cleared the codes? and do they all return? The 12 volt battery sensor can be gently prized out of the old battery and simply glued or taped to the top of the new battery. John

The first code (PO517) relates to an open circuit temperature sensor on the battery "probably a broken wire or poor connector" POAC2 is open circuit battery current sensor. This is a coil through which one of the battery lead passes through that senses the current load on that lead. Again check for bad connections. POADC/ POAEO are the main DC HV contactors and are supplied with 12 volts by the HV safety link contacts being made only when the link is in the full home position. John.

The bulbs only go in one way, but must be seated properly. There are two wire clips that hold the bulbs in place, and these can be a real pain to get into place correctly. I do not know what the IS is like for access, but if other models are anything to go by they will be difficult bordering on impossible to get at or even see. John.

D4R bulbs are designed for reflector headlights. D4S bulbs are designed for headlights with glass magnifying headlamps. They should not be interchanged as this will destroy the beam pattern, and dazzle oncoming drivers. Have the height of the beams set by your local garage to the highest legal setting. Lexus seem to set the lights at the lowest setting. John.

The hole was almost certainly in the rubber boot meant to protect the piston from dirt, and water. Once the boot has been compromised the piston will quickly seize. John.

Sorry for the slow reply as I have been away for a few days. I am still working on a realistic solution to the problem. I did have some success using a small TV main board mirroring the tablet or phone to this then using the video out to supply the OEM screen. This is cumbersome to say the leased. For those that have android devises with HDMI out it should be possible to use a HDMI to video converter, and injecting this into the OEM screen. My android systems do not support HDMI so I am still working on it, and will post here as soon as I have a viable solution. In what area of the Westmids are you in? Although I live in Herefordshire I go over to Stourbridge at leased once a week, John.

I made up my own system, but off the shelf systems are available. Linked below is a system from the US that shows just how simple it is. I have found them on Ebay UK for circa £100, but one can be built from ready available parts for less than £50. The oil take off and return is simply a "T" piece inserted in the oil pressure switch take off point next to the oil filter. This can be seen on the GS450H down below the front of the radiator. The flexible oil tube can be a grease gun tube. These cost around £2, and have the correct 1/4 inch BSP threaded ends ready fitted and are safe to use with oil at over 5000 PSI "the car lube system runs at about 50 PSI". A 12 volt oil control solenoid almost completes the system except for a suitable oil container capable of holding oil at around 50 PSI , and a timing devise to turn off the solenoid after the engine has started. All components can be mounted in the ample space in front of the radiator in close proximity of the oil pressure switch When you go to ready mode the solenoid is turned on to open it releasing the oil under pressure round the engine before the engine starts. On the Toyota/Lexus hybrids there is a normal delay after going to ready before the engine starts. In this time the oil circulates round the engine from the oil stored under pressure in the container. When the engine starts the solenoid is turned off and as the oil pressure rises oil is returned to the container back through the solenoid valve as these work as one way valves allowing oil to flow back into the bottom of the container under pressure compressing the air above the oil. ready for the next restart. The system requires some extra oil depending on the size of container held in reserve in the container under pressure. The oil is only transferred into the engine at prestart, and is then returned to the container after the engine is running at full oil pressure. https://www.ebay.co.uk/itm/Auto-Engine-Lube-Pre-Lube-Oiler-Tank/222645149806?hash=item33d6af606e:g:BQwAAOSw-RRXBrTm John

You do not need to remove the tyres from the rims. just breaking the tyre bead off the rim on the outside will give enough room to remove the tyre valve. This also means you do not need a rebalance. If you wish to use the car while you change the batteries you can fit standard rubber valves in place of the monitor valves to enable the tyres to be reinflated. John.

See my earlier post linked below. John

Any replacement monitors will require registering in the cars ECU. You can fit new batteries in your old units at a fraction of the cost of replacement, and then there is no need for registering them. John.

If the noise bothers you a relatively cheap cure that will also help with engine longevity is a prelube system. This pressurizes the complete engine lubrication system before the engine is turned over for starting. I have fitted a system to my GS450H, and this has completely eliminated the rattle. John.

I would be looking at the prop shaft couplings, and possibly drive shafts rather than a gearbox issue. John.