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So this morning I put my seat belt on, drove up to a traffic light, held the brake down, pressed the button, and.... nothing. I am almost positive this is one of the most trivial retrofits. Just need to figure out what tells the system to activate, the buttons probably just acts as a relay. I will go through TIS and figure out what else is needed to make this work. Stay tuned.
Eddie - I think the Brake Hold feature works by using an isolation valve in the ABS unit to create the pressure to the rear calipers. There are some safety lockouts like the seat belt must be fastened before the Brake Hold feature can work, and the electronic parking brake is automatically engaged if the Brake Hold feature is held for longer than x minutes, and the Brake Hold feature is automatically disengaged if the transmission shift lever is moved to Park or Reverse, etc. I rather doubt the GS 350 is setup mechanically or wired electrically for this feature. And, I do not think the instrument cluster has the green and yellow Brake Hold icon lights (image below). Maybe there is a practical way to add the Brake Hold feature, but it sure would be easier to add this feature if it had been an option on the car and was already pre-wired and mechanically setup so it could be easily added.
I have this hold feature in my 450h, but my car has a 2 part braking system. The rear is brake by wire, electronically controlled and the front is conventional, controlled directly from the brake pedal. Not sure if this is relevant, but I guess some regular 350's have it with conventional brakes all the way around.
Honestly I don't even use the hold feature regularly, maybe a few times to try it out.
I guess take a flashlight and look at the instrument cluster to see if it have the hold lights.
Eddie - I think the Brake Hold feature works by using an isolation valve in the ABS unit to create the pressure to the rear calipers. There are some safety lockouts like the seat belt must be fastened before the Brake Hold feature can work, and the electronic parking brake is automatically engaged if the Brake Hold feature is held for longer than x minutes, and the Brake Hold feature is automatically disengaged if the transmission shift lever is moved to Park or Reverse, etc. I rather doubt the GS 350 is setup mechanically or wired electrically for this feature. And, I do not think the instrument cluster has the green and yellow Brake Hold icon lights (image below). Maybe there is a practical way to add the Brake Hold feature, but it sure would be easier to add this feature if it had been an option on the car and was already pre-wired and mechanically setup so it could be easily added.
I will check the cluster tomorrow to see if it is there. If it is, awesome. If not, boy will that suck because I'm not spending money to get a new meter. That is a rabbit hole I ain't going down (e.g., tamper flag, mileage calibration, ECU sync, etc.).
Originally Posted by peasodos
I have this hold feature in my 450h, but my car has a 2 part braking system. The rear is brake by wire, electronically controlled and the front is conventional, controlled directly from the brake pedal. Not sure if this is relevant, but I guess some regular 350's have it with conventional brakes all the way around.
Honestly I don't even use the hold feature regularly, maybe a few times to try it out.
I guess take a flashlight and look at the instrument cluster to see if it have the hold lights.
Yep, will check tomorrow. Frankly, after taking half my car apart in three days, I am realizing where part of Toyota's manufacturing efficiencies come from. After working with German cars, I have learned to appreciate the Japanese way lol. Regardless, I will check tomorrow. I just find it hard to believe that the harness includes all the relevant connectors yet does not function. I have noticed that typically the ECUs and switches are the only thing our cars do not have but the features themselves can be added. Again, I will keep trying. Also, can't find the wiring diagram for the switch. It's shown in the diagrams but no indication on it. Going to keep digging.
Found the wiring, progress... Brake Hold is called Satellite Switch, N42. It's called a satellite switch since it could have both Night View (2013) and Brake Hold or Nigh View Only or Brake Hold Only. Digging...
I watch with great enthusiasm - certainly a basic feature this car is missing. Does anybody know whether it's something that can be enabled via techstream?
I wonder whether the fairly useless 2 second hold (by depressing the brake pedal) can be extended for much longer - that would be unreal. The question is whether it's hardcoded in one of the ECUs or set in techstream. I'll have a look tonight, here's hoping I don't break anything!
I watch with great enthusiasm - certainly a basic feature this car is missing. Does anybody know whether it's something that can be enabled via techstream?
I wonder whether the fairly useless 2 second hold (by depressing the brake pedal) can be extended for much longer - that would be unreal. The question is whether it's hardcoded in one of the ECUs or set in techstream. I'll have a look tonight, here's hoping I don't break anything!
I was going to eventually check techstream but if you are doing it, let us know!
Interestingly, I can't find a part number for the meter that has the brake hold. Then again, the descriptions are not that descriptive. The GS450h had it but even that I can't find the right part number. Odd. :|
Yeah, interesting it shows this on the GS350. I have the button plugged in to the correct location and harness. Going to check out techstream tomorrow and see if it has anything to do with firmware/feature activation. And considering my display does not have the "HOLD" light, I will try to press the button and see if the brakes still operate. Who knows, it may work?
Interesting yet strange. I'm wondering if GS 350 sold in some other countries may have been equipped (or possibly optioned) with the Brake Hold feature...
10-05-18, 11:19 AM
