TERMINAL FAILURE - Coolant in Inverter

Toyota Rav4 EV Forum

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Well-known member
Nov 14, 2012
San Diego county, California USA
First, let me state that in order for these cars to survive well into the future, there are a few components that need preservation at all costs.

1) The Gateway ECU - this Tesla custom made computer combines the Toyota vehicle with the Tesla drivetrain. There is no currently known method to repair these, and not much that you can do to help them. If the car becomes totaled, PLEASE, remove this component and call me.

It takes just 5 minutes with simple hand tools. It is located at the left rear of the vehicle, behind the black plastic removable cover.

2) Motor Inverter assembly for the drive motor. If this gets full of coolant, it is usually terminal for the inverter. There are no replacements for this assembly.

We recommend installing a “tell tale” hose that will permit leaking coolant to drain from the inverter. We can install this for you.

The day is coming when all the warranties have run out, and we are on our own. Let’s start that journey together.
Hey Tony -

A couple thoughts about this... maybe you already know the answers..

1. Gateway ECU - is this truly custom hardware or is it more like a part used elsewhere (other Tesla vehicles, etc) that has been co-opted into this role by way of customized firmware or similar?

2. Drive unit - I know about parking pawl, etc, but are these units different from their Tesla car cousins that parts cannot be interchanged or perhaps whole modules transplanted from one to the other? Seems kind of hard to believe the RAV components would be 100% custom. I’d have thought a standard Tesla part perhaps customized ( de-rated ) by way of firmware or so. Of course, the custom parking pawl hardware serves as evidence that they definitely could make them custom and unique...

3. Battery - this feels like the biggest issue to me. They batteries are destined to eventually fail. How does one replace this? More so, with new ev coming on the scene with much better range.. I wonder if the RAV will just becomes irrelevant if there is no way to improve its battery ( either by restoring to original spec or, ideally, by upgrading somehow to be closer to range spec of current crop of available EVs).

I’m curious your thoughts on these...
Tony, it's impractical for me to get my car to your shop for the motor inverter drain hose install. Are you willing to share in detail what and where you install a drain line, so I can have it done locally or DIY?
A cursory internet search didn't lead me to the information I seek: what is the best location to drill a drive unit weep hole, to allow any coolant leakage to drain onto my garage floor, rather than accumulating in the DU's inverter? Drops of coolant on my floor would be a good early warning that the unit needs an internal reseal.

A photo with an arrow pointing to the location would be great.
asavage said:
... A photo with an arrow pointing to the location would be great.
Take a look

from https://photos.google.com/share/AF1QipNb3tKJYPQpYjbX5qyQYV5crZspYhDeIPlRPkL53tDdflzRYxezu_ypSV4JfflioQ?key=TGE5dTlidWtyMXJ4TzNHZEZfdGhoWm4xRzFkWmtB
and this "devices" :)

I'm a supporter of using such a device (simple and inexpensive) with sound and LED indication