Delphius1

A lot depends on whether the problem is mechanical or electrical.

There is a known problem of the rubber boot over the unlatch switch cracking and the switch failing due to water ingress. So the first step is to investigate the rubber boot, press the button and see if the latch motor whirrs. If it doesn't whirr, the issue is most probably electrical. Possibly the switch has failed, but it will need investigation. Checking the motor gets voltage when the unlatch button is pressed is the first step, then work from what you find.

If the motor whirrs and attempts to unlatch, then the problem is most probably mechanical, or there isn't enough power in the Battery. Possibly the linkages have seized stalling the motor, or the Battery can't deliver enough power to the motor , or the linkages have become disconnected. 

I did have this happen to me once and it turned out to be a discharged 12v Battery. The Battery didn't have enough power to drive the latch motor to unlatch the tailgate. But then it also didn't have enough oomph to turn the engine over either. 

With the windows, press and hold the down button until the window stops at the bottom, but keep holding the switch for a couple of seconds after it hits the bottom. Then lift and hold the switch to lift the window and keep holding the switch for a couple of seconds after the window hits the top. Repeat for each window.

Now the sunroof. Pull and hold the switch back to open the sunroof and keep holding it for a couple of seconds after it hits the back position. The push and hold the switch forward to close the sunroof and hold it for a couple of seconds after it closes. The sunroof should be reset. The tilt switch shouldn't need reesetting.

If you get any nasty noises like slipping cogs, release the switch immediately and sort the cause of the noise.

I'm not overly worried that my 15 year old RX is going to be stolen. It got security built in, has ultrasonic sensors and doesn't have the advanced keyless entry/start keys.

Old skool technology wins!

One thing in Lexus's favour is they aren't as prone to theft and parting out/shipping abroad like top end German cars, LandRovers and Land Cruisers.

Plus on mine the scabby wheels and the smell of oil from the leaking cam cover gaskets would put most thieves off. :-D

One option would be to use a Bluetooth dongle plugged into the OBD2 port. Most of the compatible smartphone apps have the ability do show the sort of information you need like MPG, distance to zero, fuel level etc. and show it on a smart phone screen. If you have an old android smart phone sat in a drawer, then it can be resurrected with the right app as an eco-readout!

You may have to put the tank capacity into the app as that data isn't available from the vehicle, but once you program it with the tank capacity and where the fuel level is reading, you can get a readout of tank capacity and miles to zero.

Of course the accuracy is only as good as the information you put in, but that's really the only way to generate the information.

On the plus side, maybe you can wangle cheap insurance from LV. It's their colour..

Don't forget that sealed AGM and Gel batteries have low charge rates (to avoid gassing) and need regular long runs to recharge them, or the occasional recharge at low charge rates to bring them back to their best.

Lots of use of accessories and short journeys coupled with a miniscule charge rate can significantly reduce the amount of charge in a Battery over time until its on its knees so to speak.

Some sealed AGM and Gel batteries can take up to 7 days to fully recharge from fully discharged because the charge rate (by design) is so low.

I used to design and test power supplies that used such batteries and in automotive applications they have their limitations. Which is why car manufacturers in general have gone back to wet lead acid or are looking at lithium based batteries (but lithium batteries have their own set of issues).

Ah, ok. Progress isn't always forwards!

It would be interesting to see if a smart keyless car can be programmed with Techstream. YouTube videos say it should be possible with a replacement key fob.  

Hi,

Is it the same 3-button key as the RX300? If it's the smart keyless entry/start then that's different.

I created a new 3-button key for my RX300 a few months ago. The process should be straightforward. It cost me about £40 to create a spare key.

I bought a used key off eBay for £25, but made sure it have the same markings on the back. That way the electronics in the key were the same as the only working key I had.

Once the key arrived from eBay I junked the case because all I wanted were the electronics in the key. The electronics interface with the security system (the immobiliser) and also the central locking.

I bought a replacement blank key from eBay and got the blade cut to match the currently working key. So the key would turn in the locks, but the electronics needed programming.

I used Techstream software plugged into the car to get it to recognise the "new" (new to the car) immobiliser chip in the key. Then it was just a case of going through the rigmarole needed to get the central locking part of the fob recognised by the car.

There are a few how-to videos on YouTube if you search for RX key programming..

The details are here:

The main fan should come on around 90-100 degrees. I've not checked it on my cheap Bluetooth OBD2 dongle and phone, but most cars come on around that temp.

The secondary fan should be on all the time as soon as you switch the A/C on.

If the car has the ultrasonic pack by the dome lights, then try and hold the off button on the ultrasonic unit for a few seconds to switch the sensors off an see if that makes a difference. The security light on the dash should flash rapidly when you press and hold the off button and that shows the ultrasonics are switched off.

That rules out sensor issues, or possibly a window slightly open messing about with the ultrasonic alarm sensors. I doubt in this weather you're leaving the sunroof open. ;-)

If the doors are left open, or the switches are broken to make the alarm think they're open the beeps sound immediately when you press the lock button, not after a few minutes. If the windows or sunroof are open a small crack, a breath of wind through the gap can trigger the ultrasonics and that can happen any time after the alarm is set.

Other than that, possibly a weak Battery draining too much too quickly may set it off.

Of course once storm Gareth has gone, if the alarm stops, then it was just the wind pushing the car around and triggering the vibration sensor.

I just wonder if the Battery has been disconnected, have you turned the steering from lock to lock a few times to recalibrate the steering system?

Have you tried turning the steering to full lock, holding it there for a few seconds and then turning to the opposite lock and holding for a few seconds and then back to original lock and holding for a few seconds?

The steering system may have to relearn where each maximum steering angle is so it can then display the lines accurately.

If you search for superpro, you can see my posts about having polyurethane bushes fitted.

I second what Gliderpilot said, front lower arm swapping is a pig of a job. Even if you just swap the arms with bushes pre-installed.

The engine has to be lifted and the subframe dropped to allow the engine mounts to be removed and get access to the bolts securing the front arm mountings.

On My RX300 the low fuel light comes on with around 50 miles range left on the info display. I've run it down past zero miles on the info display by a further 5 miles and still ran the car to a petrol station. Not by choice, but when I was out in the sticks late at night in an unfamiliar area trying to find an open petrol station.

That night I understood what electric vehicle drivers feel regarding range anxiety.. :-)

The self-locking "issue" on my RX and being pretty forgetful/accident prone was one of the reasons I got a second flick blade key cut and coded it myself. Now I always have a spare key available even if I have to go home and get it. If I'm travelling away from home the spare stays in my "other" pocket. Being a flick out blade key, it's pretty compact, so doesn't take up much pocket space.

The expansion tank on the RX is not pressurised. When the coolant heats up and expands, it pushes past a spring-loaded valve in the radiator cap and fills the expansion tank.

When the coolant cools and contracts, a vacuum is creates and the coolant in the expansion tank is sucked past a second valve in the radiator cap to maintain the coolant level.

If the return valve is stuck, or the small bore pipe from the expansion tank to the radiator neck is blogged, the coolant can't return to the radiator.

The vacuum caused by the contracting coolant causes the hoses to collapse. 

The good news is you have no leaks in the coolant system, but it does need seeing to as it will affect coolant flow at colder engine temperatures.

An aftermarket radiator cap shouldn't break the bank and neither should checking the expansion tank hose for a blockage. 

Hi,

The 400h has a CVT gearbox on it. Not the best for towing and the gearbox can be easily damaged by hard towing use.

The best gearbox for heavy towing is either a manual or an auto with a torque convertor. The CVT, DSG and similar modern automatics tend to not cope well with heavy towing use. For instance slowly reversing a big caravan up an incline, like you would manoeuvring a caravan in reverse up onto a drive. It can be hard on a manual clutch, let alone the modern semi-auto boxes (but at least on a manual you instinctively know when you're abusing the clutch and give it a rest... DGS gearboxes don't. The wet clutch DSG boxes fare a bit better because the oil tends to have a cooling effect, but the dry clutch DSG boxes have a habit of failing to pull the car on it's own, let alone a heavy trailer. CVT gearboxes can burn out belts and/or drums if pushed too far. A torque convertor box will just sit there spinning fluid around with just a moderate increase in heat.

Not knowing exactly how the motors on the 400h integrate mechanically and electrically with the drive train, I'd say walk away.

Although it would be handy to plug a techstream in to see how many error codes the transmission has. :-)

Reminds me of when I had my old ratty Vauxhall Vectra in the snow years ago. A VW 4x4 driver was trying to get up a slight icy/snowy incline using the Jeremy Clarkson method (more power!). He was making no progress on this slight incline and spinning all 4 wheels. In fact he went backwards more than forwards.

I got fed up and pulled out around this idiot in my ratty front wheel drive car and drove past with non-spinning wheels gripping the snow and ice. He just looked out of his window dumbfounded...

This weather does bring out the more thoughtless and inconsiderate drivers.

Mind you, my driving instructor was a bit of a comedian. On my lessons where it had snowed, he used to get me to drive up onto the moors and then tried to find the worst icy hill for me to climb. I generally got up all of them. Those were the days back when we had real snow. 8ft banks either side of the road.

Looking at all the leads available, I can't see any leads on amazon or eBay that match the picture of the leads on your car. I just wonder if the available leads are designed to plug in somewhere else?

Are those the connections into the back of your Radio?

You might have to go to a car audio specialist and they may be able to look up your car's details and get the correct lead. They would have a better idea of which lead you need.

I think only two of those connectors are used on the Parrot system. Looking at all the pinouts for the RX radio, the signals to the amp and the power are contained in just two connectors. I assume  the third connector is for other stuff like the steering wheel controls.

Basically all the leads have to do is pass through the signals between the radio and the amp, and break out power to the Parrot system and any signal wires the Parrot system needs access to so it can work. So you have connectors that your original wires connect into, then they plug into the back of the radio. Any signals that need to break out from the wiring go to the ISO connectors which the parrot plugs into. Not having fitted a Parrot system before I'm guessing, but that's how I'd assume it works.

The Parrot may tap into the lines to the amp in order to provide audio from the phone through the car speakers instead of using the mute line. But that should be taken care of with the ISO connections.

I have a Nokia install on my RX and it has a separate speaker for the phone audio, so it just mutes the audio using the mute line.

I've found this video showing install on a Honda. The install on the RX should be similar on the wiring, except you plug the adaptor lead into two connectors on the RX because the front left, front right, rear left and rear right channels are split across the two connectors. So you fit the pass through lead you need to buy for the RX and then plug the Parrot loom into the ISO connections.

My mechanic did it with the engine in situ, jacked up as high as it could go on the upper mounts and the subframe on the last few mm of thread. That gave just enough room to wiggle the lower engine mounts out with a bit of effort so the arm mounting bolts can be undone. 

Got to love Lexus packaging. NOT!

Designed a little better it could have made the job tons easier. 

Hi, It's those front suspension arms and bushes... they are an absolute pig to change. Even if you go for replacement arms (the easy option because the bushes need a hefty press to press them in),.... to remove the arm mounts you have to prop the engine up and drop the subframe.

I've had polyurethane bushes fitted on my front arms and my mechanic said it was one of the worst jobs he's done. He propped the engine up as far as the engine mounts would allow and then undid the subframe mounting bolts until they were on their last few mm of thread. At that point he could just about remove the side engine mounts which cover the bolts holding the front arm mounts. to the subframe.

The discrepancy could be due to one garage knowing you can just about get away with the skin of your teeth by doing what my mechanic did and the other garage going the whole hog and pulling the engine and/or subframe from the car and making an even bigger job of it. i.e. quoting for worst case scenario.

Even doing what my mechanic did, it was the best part of a two-day job to get everything into the position he could remove the arms, remove the old bushes from the arms and fit the new ones in and then re-fit the arms. Luckily I got mates rates. :-)

Hi, I'd lubricate the cables, the door handle mechanism and the lock mechanisms. I see it on MX-5s where the cables get a bit dry and start to seize, defeating the central locking actuator. Lubricating the cables and the lock latch mechanism frees things off and you should be back to normal. That lovely lock/unlock indicator on the door handle is a great idea and handy, but it needs to work freely so the lock latch doesn't stop working.

It still gets me how different Japanese manufacturers use similar mechanisms in their cars. European cars are all quite different from each other, but Japanese cars tend to use very similar concepts between manufacturers. It makes working on Japanese cars so interesting. I've owned and worked on Supras, Mx-5s, Mitsubishis and now my RX and I still find odd things that are common to more than one car across different makes. It's almost like there's a door lock guy in Japan and they all go to him to design door locks for them, he just does something slightly different for each project. lol.

In that case you may have to have a word with a car audio specialist to see if they can source the correct lead for you.

What lead is it you need? That one on amazon seemed to have the correct connections to connect the Lexus loom and break out the connections to the Parrot unit.

Hi,

Doing a Google search of "lexus rx300 2004 parrot" threw up a number of options. It looks like the cable is available on eBay and amazon.

For instance this link on Amazon: https://www.amazon.co.uk/PaRROT-Adapter-TOYOTA-LEXUS-BLUETOOTH/dp/B009EO6JQM

The compatibility list states RX300/330/430 (2004 onwards)

Is this any good for you?

Just before Christmas i came home from two week's holiday to a car with a flat Battery and no central locking.

Access was a problem as the key had never worked in the door unlocking the car, only locking it. Turning the lock barrel to unlock the door was prevented. So getting at the bonnet release was initially impossible.

However, lots of penetrating oil and working the key between lock and unlock eventually got the door lock to work in the unlock position.

So it seems the lock barrel can work in the lock position, but be seized in the unlock position, which I've never encountered in a door lock before. 

Just for info, in case anyone else is in the same position. Penetrating oil and effort can get the door open so you can open the bonnet to charge the Battery.