Sami Tilander

This might help you: https://www.clublexus.com/forums/gs-3rd-gen-2006-2011/801577-tpms-tire-pressure-monitoring-system-schematic-and-disable-attempt.html

Source: https://www.amayama.com/en/genuine-catalogs/epc/lexus-europe/gs450h/GWS191L/4280/electric/8435 BR. Sami

I'd assume that US has more GS350 models than Europe... quickly searched the Ebay with part number 8824030420 and there was few used modules available... BR.Sami

I had the same trouble... I was also considering buying the RHD module, because I ended up to the same conclusion that the only difference might be the mounting bracket. Luckily I found one LHD ecu with reasonable price. Have you checked the Ovoko? They seems to have two LHD modules right now: https://rrr.lt/en/search?q=8824030420 BR.Sami

The radar seems to be same in GS350 and GS450h. I don't free access to the wiring diagrams, I've been using the official Lexus-Tech documentation: https://www.lexus-tech.eu/OnlineSubscriptions.aspx It costs only 5€/hour (+VAT)... BR.Sami

Which Distance Control ECU did you get for GS350? I checked from Amayama the part numbers and it seems that GS350 and GS450h have different variants of this ECU: https://www.amayama.com/en/genuine-catalogs/epc/lexus-europe/gs350/GRS190L/3953/electric/8408 GS350 should have 88240-30410 (RHD) or 88240-30420 (LHD), but GS450h has 88240-30460/30470... Might cause the problem? Br.Sami

I was checking the wiring diagram for radar cruise, and I noticed that one wire to the radar comes from Hybrid Vehicle Control ECU. I and Ollie seems to have GS450h models, but you mentioned that you have GS350? Could you check that this wire is connected to somewhere in your car? That diagram is probably for GS450h, so I don't know if it is valid to GS350 or not... but maybe one thing to check...

If I remember right, it took several attempts to get it changed. Don't give up, you are very close! If you are able to access the Distance Control ECU with TechStream, that should be working correctly. Double-check the wiring between radar and the fuse box. BR.Sami

Whole Europe uses 433MHz accourding to https://en.wikipedia.org/wiki/Direct_TPMS Tire shops have handheld scanners to read the sensors, but if those are out-of-battery already, that does not help. BR.Sami

Amayama? https://www.amayama.com/en/part/toyota/g904030010 (does not include taxes, import fees, etc, but might be still cheaper...) BR.Sami

Not maybe the easiest, but I replaced the fog lights of my GS450h with LED DRL+Fog lights combo. See this old thread: BR.Sami

The "Check System" message indicates that car's ECU cannot communicate with one (or more) sensor in the wheels. Possible causes: sensor out of battery, sensor ID wrongly programmed to ECU, no sensor at all, ... A decent tire shop should be able to scan the sensors to see if they are alive or not. BR.Sami

Small update on this: I finally managed to sort out the steering wheel topic... I only changed the stalk (with "mode" function) and hacked the wiring harness so that the same "mode" function on stalk can be used to control the "distance" of radar cruise. Now it works so that a short push on stalk changes the distance and a long push switches between radar/normal cruise modes. I was ready to sacrifice the "mode" functionality as I have never even used that, but there was no need for that... BR. Sami

TPMS sensors are available in two frequencies: 315MHz and 433MHz. If you looking international websites, ensure that those TPMS sensors are using the correct frequency...

About the TPMS warning: are you getting also message "Check System"? If yes, then the car's ECU cannot communicate with the TPMS sensors (one or more) of the wheels. You mentioned about new tyres: did you also got new sensors? Were they properly registered to the ECU? BR.Sami

The "Check System" message means that TPMS ECU cannot read the sensor. If you have not changed anything, it is very likely that one or more sensors are running out of batteries. They last about 10 years. BR.Sami

You still need to find out the culprit... Batteries do not "sent out power too intensely", but there is a short-circuit somewhere. If you don't find that, it will happen again even with standard 12V battery... If the main fuse is blown, the short-circuit must be in the wires leading from battery to the other fuse boxes. That narrows down the search a bit. One thing bothers me: if your main fuse is blown, how the interior lights can work? BR.Sami

Check also this old thread, lots of information there: BR.Sami

Job well done! One question: what is the purpose of that BSM button? I'd assume that the BSM function would be always on... Btw. there is a thread about retrofitting the radar cruise to GS, might be similar to IS? https://www.lexusownersclub.co.uk/forum/topic/131146-lexus-gs-450h-sport-radar-cruise-control-retrofit/ BR.Sami

Actually I've not done anything for the steering wheel yet. The system goes to the radar mode and long distance, as those have been enough for me so far. I bought a pre-facelift wheel, but I don't have airbag for it (I cannot use my airbag as the cover is different), so I probably just utilize the control stalk from it and try to cope without that distance selection button. Have you ever switched back to the normal mode? In any conditions? BR. Sami

I absolutely love it! I've been testing it on different roads and it works like a charm. I was a bit surprised how heavily it actually brakes. I haven't yet done any adjustments, just checked the the current aiming: the beam axis was only 0.9 degrees on left-side, so it was pretty well aligned (and actually I didn't find a proper tool to adjust the radar: I've the older model which seems to require a 3mm hexagonal socket, which I don't have...). May I ask from where you have found that new steering wheel? I've been searching for that exact same model (black leather with smaller buttons) for almost 2 months now, but haven't found any... BR. Sami

Thanx Ollie! I followed your instructions and I've also now adaptive cruise control! Awesome! Couple of details from my installation: 1. I did not have the connector for the radar, so I had to buy it. The part number for the housing is 90980-12292 and the terminals 82998-24250. 2. Part number for the terminals in the other end of the wire: 82998-12690 3. I used 0.75mm2 wire which was too thick for the terminals. Maybe 0.5mm2 wire would be better... 4. to set the L/C Flag to Yes, I had to first execute the Initialization for the Laser Cruise using TechStream and then follow the sequence mentioned above. 5. I made a radar reflector from a thin (1mm) aluminium sheet (and tested the beam adjustment using TechStream): BR. Sami

yes, it is at the top of each shock. Maybe this picture helps... Stepper motor and the actual shaft it is turning are highlighted with yellow. To access the adjustment, you just need to remove that dust cover and the stepper motor. BR.Sami

You could try to manually adjust the dampers... just to see if the dampers are fine and the problem is in the control electronics. There is a stepper motor sitting on each shocks: temporary remove those and adjust the damping with a small flat screwdriver. BR.Sami

Here are couple of pictures underneath of GS450h 2008 (if it helps...): BR.Sami