markirl

Thanks for the reply. So the Techstream is displaying that it can connect to the Hybrid Control ECU but it gives back no codes, monitor is greyed out and if I try and get live data, it gives me the error - I don't think it's communicating properly. It's a v1.4.1 firmware cable which I think may be my issue. Car isn't throwing up any codes of importance across any either the Engine or gearbox ECU which I find bizarre. Mark

Hi folks, I have replaced the bearings in the transmission pump as per the other threads. Car drove fine afterwards apart from a very noticeable clunk at times when the engine shut off. So my Mini VCI cable arrived and a scan has shown up no real issues with the car. However, I am getting occasional random misfires according to the diagnostics (but isn't throwing any codes). I also don't appear to be able to read the hybrid system as I get an error each time. When it's running now, it appears to have a loud hum or vibration when in the cabin that I don't remember from before. I'm thinking that either the transmission is stuffed or the timing chain has jumped a tooth - any thoughts?

So I didn't do this step, but just tried to test the motor off the car. My understanding regarding motors was that there should be no continuity between ground and the windings but each of the windings should have a resistance to each other - I got 0.9ohm between each stator but open circuit to ground, which I would interpret as a good motor?

I've disassembled my pump and replaced both bearings. The existing bearings were NSK and poor quality, they had both dumped their grease too and were dry. I'm crossing my fingers and hoping this is my issue (needed to be done anyway). Interestingly, I had to drill off the heads of the screws (used 7mm drill bit oversize) but no need to re-tap as a pair of pliers on the ends extracted the remains. There is also some corrosion on the mating faces where it appears that the pump wasn't assembled properly. Tonight's plan is grab 3x 16-18mm M5 screws tomorrow and then reassemble the whole lot, on my driveway using a couple of old 20cm high ramps :( Also found a broken exhaust clamp (just hanging on) and a broken earth strap on the car, plain as day to see. The car was in with Lexus last week and I asked them to give it a full check over - I feel like I totally wasted my money as they clearly didn't.

One final query/verification - Instructions earlier in the thread say to fill the car from the top "fill" plug, and there is a second plug slightly lower which is the level plug? Every auto transmission I've worked on has just had a fill & drain plug, so want to be sure that this is the case!

Thanks for the advice, I'll get some fluid from Toyota. I think I'll leave dropping the sump until I'm sure that this pump fix fixes my issue!

For those that have done this job, did you fill the transmission with new fluid or re-use the fluid that came out. I've read differing opinions online and I'm concerned about underfilling/overfilling the transmission.

Thanks, looks like I'm missing two covers - the one under the engine and the one under the gearbox. I wonder did this have an affect..

Thanks for all your help - this is a fantastic forum!

Ok, I will order a Mini VCI tonight, thanks. I believe the pump is at fault, must have completely seized throwing an error and not allowing the car to be driven and I will hopefully rectify this with a bearing replacement. My car appears to only have the radiator splash guard, and no other. This is frustrating as I'm nearly sure it had the main splash guard when I bought it as I remember looking around it for leaks. It went into Toyota for a service so I guess I could ask them if they still have it...

Also, should my car have an undertray under the back of the engine & below the gearbox?

Apologies for being unclear, what I meant was the engine sounds fine until the horrible grinding noise came in from the transmission area. Regarding the 12v battery issue, I'd read up on it and the thermistor was placed on the new battery at the time. So to clarify the above, previously the car would go to "ready" mode, then engine would turn on and approx 2-3 seconds later, the check EBC and check VSC warnings would show up and the car would stop running accompanied by some grinding noise from the transmission tunnel area. Since posting this thread, I have read this excellent thread: GS450h Loss of Power which describes a pump in the area of the noise I was hearing and a friend came over with a scan tool. The only code the car would produce in the generic sealey scan tool was P3191 which just means "engine did not start". We decided to try and start the car and low and behold it started perfectly, but not without a very short grindy noise from the transmission area, then just a consistent mechanical light clicking noise. Car is currently charging and running perfectly with no errors. I will go out and check it again once it has cooled down again. So I believe my issue is the transmission motor pump unless anyone has any other suggestions?

Hi Folks, I bought a GS450h last week that has been lying up for a while. Have put about 500 miles on the car and really enjoying it. However, today when out in torrential rain the car popped up with the dreaded Check Hybrid System message, followed by check EBC & check VSC. It did the same thing when I bought it as the 12v battery was dead but I have since installed a new one with no issues since. I managed to get the car home on hybrid only mode but have drained the battery down to 1 bar. When the car tries to start now there is a horrible grinding noise from the transmission tunnel area. The car felt like it was misfiring shortly before this happened and wouldn't run smoothly - it now appears to start and run fine. Car is basically completely immobilised, I'm trying to find my scanner but does anyone have any suggestions? Thanks in advance.