Great pics, thanks for the writeup- 2 questions.

Appx mileage on your R4P?

Also, I haven't had time to dig through the mega thread on this. Is it just the RF shield that's corroding and failing, or is the conductor in the orange insulation failing? If it's just the shielding this seems like a expensive dealer repair, but a nothingburger DIY. Is my read on this correct?

BTW, saw your post on the other thread regarding CRC. We use CorrosionX in aviation. It's good stuff too. I've got some in the garage. I'll shoot my braid one day when I have time.

 

Do you wash your car undercarriage regularly during the winter? That seems like a lot of rust for only two seasons!

 

Just over 18,000 miles since late Sep 2020.

Yes you are correct. I think it is just the RF shield that’s corroding, eventually breaking a test circuit that triggers vehicle shut down. Understandable that vehicle stops if a main power wire harness detects that the RF shield was just compromised. It could be from a collision under the vehicle or something that seriously compromised a main power wire. The few picture of the actual 3 phase power connector internals all look clean (inside connector) and secure. Some people apply (the right) product there while they are cleaning/treating RF shield.

I’m just regurgitating CRS/product/solutions from the Hybrid thread that I though were sound and worth pursuing.

Good salt/rust question @ColoradoPrimeTime.
I occasionally (2 - 10 times per year) go through brushless car wash and I do spay the undercarriage. The undercarriage spray does not have a direct path to the RM connector because of the tray in the way. With the amount of road grime inside my connector, I think just driving it makes if collect dirt. Syracuse uses (some) expensive Potasium based road salt that works better and corrodes metal faster. I never got the benefit of Toyota hybrids not needing pad and rotors because of regenerative braking. The Syracuse winter salt eats up pads AND ROTORS every 3 years or 30k (big plus/minus margins on these numbers).

 

Syracuse uses (some) expensive Potasium based road salt that works better and corrodes metal faster. I never got the benefit of Toyota hybrids not needing pad and rotors because of regenerative braking. The Syracuse winter salt eats up pads AND ROTORS every 3 years or 30k (big plus/minus margins on these numbers).

Some might consider this a design flaw 🤔

😳. No one complains about what it's doing to the environment.

 

Thanks for the info. Yeah I grew up in Buffalo so I know what those winters are like, haha.

Guess I’ll be buying some CorrosionX this weekend… can never be too safe

 

Here is the other side of the orange cover that Toyota modified/removed to let water and road-grime out of the plastic cover. R4Prime has solid (trapping) plastic on both sides of plastic cover. Perhaps because of the water ‘drain’ depression on this cover, seen above. A

In looking at the pictures, unless I missed it..
they seem to be different from the Toyota modified cable shown. 🤔

 

Yes my orange RM orange cover is different. @windwalker099, thanks for the picture of evolution of Toyota’s fix for this.

 

So I took an hour to get out the ramps and get under my 2021 R4Prime to get a look at this corrosion problem. Then I took a couple of days to procrastinate writing it up in a post. Writing is always the more difficult part for me. When I think about it, the hour to perform the experiment went fast and was fun, and the writing is work (not fun).

I know it is sensational to talk about the expensive replacement/labor cost when it fails completely and stops the vehicle. I think it will be an easy DIY fix to clean off rust and use some conductor to complete RF shield circuit at base of connector to RM, if/when it fails. I’ll be performing preventative, rust preventing measures before this winter. This is a bad look for Toyota and they should fix it for everybody, but I think the impact is moderate (car will not run) and the DIY fix is minimal. UNLESS, you talk and believe (do your own diligence) dealership/stealership expensive solution to the problem.

So let’s keep the not-fun writing to a minimum and let the (sensational) picture do the talking.

Here is the result of 2 Syracuse NY winterings worth of road salt/grime (very sensational pics). I’m letting Toyota know about this today. Let’s see if I can get my Brand Advisor supervisior to give me a call-back to talk about this.


View attachment 186054

View attachment 186061



To the left of finger, it looks like a (new?) drain for the water to exit the orange plastic cover. Unfortunately, stuff (up to 2mm) still gets into the plastic cover and (it felt like) at lot of dust and dirt drizzled onto my head from there as I was removing the orange cover via two plastic clips. The clips were hard to disengage, but the cover eventually (partially) opened up an inch to see inside. I’ll be back in there before winter to clean RF shield up and spay rust preventer.
View attachment 186052



Here is the other side of the orange cover that Toyota modified/removed to let water and road-grime out of the plastic cover. R4Prime has solid (trapping) plastic on both sides of plastic cover. Perhaps because of the water ‘drain’ depression on this cover, seen above. Also note the elaborate (whatever it’s called) clamp where wires go into orange conduit. Does this orange conduit go longer (up into body) on R4Prime vs Hybrid/Gasser (2nd pic below)?
View attachment 186053 View attachment 186057 View attachment 186055 Click to enlarge thumbnails.



And here is an interesting picture showing connectors on the bottom AND top of the MG main EV connection. There were questions about why the connector was moved to the bottom where the water can/will? cause problems eventually. I will have to see what is plugged in on top and where the wires go.
View attachment 186056



Here is the removed tray that covers the RM. Note; It has good drainage hole locations but still collects road grime. It felt like that much road grime fell out of the orange cover and onto my face/head. Need to rent hoist time when I go back to mediate rust on RF shield.
View attachment 186058

Enjoy.

Thanks for sharing those pics and your observations.

Some of my thoughts: The braid for the shielding looks like galvanized (zinc) plated steel. Galvanized is a sacrificial coating, hence the dust you see. Not good to use in a wet environment. Much better would be stainless braid. The racing community has used stainless braided brake hoses for decades; I put stainless braided brake hoses on my Porsche 45 years ago and they show zero corrosion/deterioration even when exposed to the worst of Utah winters with salted roads. That should be the fix for that part, if only Toyota would do that.

I would think Toyota could do better on the housings so that road debris, moisture, and salt never can get in. They have used environmental (water proof) connectors for years and years, so why they can't water proof the entire wiring system on the hybrids is beyond me.

Just my thoughts.

 

Thanks for sharing those pics and your observations.

Some of my thoughts: The braid for the shielding looks like galvanized (zinc) plated steel. Galvanized is a sacrificial coating, hence the dust you see. Not good to use in a wet environment. Much better would be stainless braid. The racing community has used stainless braided brake hoses for decades; I put stainless braided brake hoses on my Porsche 45 years ago and they show zero corrosion/deterioration even when exposed to the worst of Utah winters with salted roads. That should be the fix for that part, if only Toyota would do that.

I would think Toyota could do better on the housings so that road debris, moisture, and salt never can get in. They have used environmental (water proof) connectors for years and years, so why they can't water proof the entire wiring system on the hybrids is beyond me.

Just my thoughts.

If the cause is contact with aluminum or another dissimilar metal, stainless steel may not be a good choice. While stainless is relatively resistant to oxidation and other corrosion in isolation, it is still susceptible to galvanic corrosion. If the braid is a shield for RF or capacitive EMI, then it must make electrical contact on at least one end. That makes galvanic action a concern, especially in an automotive environment. Steel and aluminum are relatively strong, lightweight and inexpensive compared to better conductors. Unfortunately, while using them has many advantages, this is what happens when you don't use them correctly as conductors.

It would be interesting to know the composition of the metals involved and whether the newer part also has updated metals or plating. For all we know, the original parts were plated incorrectly or used the wrong alloys or fasteners or a supplier sent them faulty parts not to spec. Or the design may have been poor. Either way, it seems like better drainage in the updated plastic housing would only be one part of a solution to a galvanic issue. Since it is still exposed to water, I'd think they also had to make a change somewhere in the metals, alloys or plating as well. It may be unlikely they eliminate this type of corrosion, but quite possible to reduce it to make the part last the life of the vehicle.

This is my assembly after 10K miles including one Chicago salty winter. Mine was made 4/2021 so after the first part change supposedly in 3/2021 according to a post in the R4P subreddit. I did not remove the black plastic undercarriage shield, so this is about the best shot I could get by sticking my phone in there.

R4P2021MGRcable.jpg

• Safedad
• Sep 8, 2022

2021 Toyota RAV4 Prime HV Cable MGR assembly 10K miles Chicago area

 

Thank you for sharing @FKHeath.

Do you think you could attach some stainless braid to bridge over corroded RF braid (after clean-up and anti rust)?

I was thinking after corrosion break, but you could do this ‘bridge’ now and not have to care ever (until rust works up above ‘bridge’ attachment).

 

I think I would prefer using "CRC 06026 Corrosion Inhibitor" because it would seem to last longer than Corrosion X

Amazon.com: CRC 06026 Heavy Duty Corrosion Inhibitor, 10 Wt Oz : CRC Industries: Automotive

Buy CRC 06026 Heavy Duty Corrosion Inhibitor, 10 Wt Oz: Corrosion & Rust Inhibitors - Amazon.com ✓ FREE DELIVERY possible on eligible purchases

www.amazon.com

And the comparison: 5:02 - 5:09 and 6:05 - 7:12

 

Toyota advisor will be like: "If aint brokn, don fix it!"

 

What would they "fix"

in lexes models they see some of the same corrosion on the RF shielding with no effect.
If you were the service adviser how would "you" justify the time and labor to replace it with no problems noted 🤔

 

^I know, I know. I’m reminded that Toyota Brand Ambassadors are payed to listen, document (case #), and say things to make you go away. BUT they have access to the only entity that CAN make a change that makes my R4Prime (BVIEO) even better -> Toyota Corp.

I have a good relationship with a supervisor and she calls me back and listens. I’m still hoping she/Toyota can fix it or tell me why the Toyota App is so bad for the R4Prime. I’ll see if she can share anything about RM cable corrosion fix (probably not).

 

I see the WeberAuto video (23:40) looking at powered circuits. I have not seen any evidence that orange cables carrying 3 phase current to MGs is corroding. I think it is just detecting the RF shield status and shutting down when disconnect/break is detected.

 

I see the WeberAuto video (23:40) looking at powered circuits. I have not seen any evidence that orange cables carrying 3 phase current to MGs is corroding.

I think it is just detecting the RF shield status and shutting down when disconnect/break is detected.

What would the logic of that be 🤔

The RF interference, a possible sign of cable corrosion, which is what they check for.. It's not a safety issue.

"14:41 How the car performs active isolation testing and passive isolation testing "

"27:35 MUST-SEE: See the results of a conductive liquid connection to vehicle chassis "


He mentions the checks and what it takes to trigger a fault. Some of the testing done prior to "on" may trigger a system alert but not a "fault" that would. alert the driver or prevent the car from starting depending on the level of fault triggered.

It's checking for resistance, once a threshold is met, it triggers an alert, or prevents the system from starting.


"Introduction:
Some 2019 – 2021 model year RAV4 Hybrid vehicles may exhibit a MIL ON condition with one or both of the following Diagnostic Trouble Codes (DTCs) stored:

• P0AA649 (Hybrid/EV Battery Voltage System Isolation Internal Electronic Failure)

• P1C8049 (Hybrid/EV Battery Voltage System Isolation [Rear Motor Area] Internal Electronic Failure)

The vehicle may also exhibit static or distortion when listening to AM radio.

These conditions may be caused by corrosion on the high-voltage wire harness below the vehicle at connector Y6 at Motor Generator Rear (MGR) or dirt and debris inside the connector. Follow the Repair Procedure in this bulletin to address these conditions.
Repair Procedure:1. Confirm the condition exists.
A. Using Techstream, run a Health Check and confirm one or both of the following DTCs are present: * P0AA649 (Hybrid/EV Battery Voltage System Isolation Internal Electronic Failure).
* P1C8049 (Hybrid/EV Battery Voltage System Isolation [Rear Motor Area] Internal Electronic Failure).
Are either or both DTCs listed above present or is there AM radio static/distortion?

YES — Continue to substep B.

NO — This bulletin does NOT apply. Continue diagnosis using the applicable Repair Manual."

Possible Issues with Orange HV Cables - ClubLexus - Lexus Forum Discussion

Hybrid Technology - Possible Issues with Orange HV Cables - Purchased my '06 RX400h back in June and it's been fantastic. Just recently I was changing the fluid in the CVT and rear diff when I saw the orange covering for the hybrid battery cables seemingly fraying at the connection to the rear...

www.clublexus.com

From an 08 Lexes...

"Yesterday, I was told that the Service tech said that it can't be "fixed."

He goes on to say that this is how it looks, even on a brand new vehicle, and that it's not a safety issue. He goes on to say that the metal holder that has corroded/oxidized will not corrode further or look differently years from now."

Rx 400h - Ever see this before? - ClubLexus - Lexus Forum Discussion

Hybrid Technology - Rx 400h - Ever see this before? - I will be getting a 08 RX 400h tentatively on Saturday from a local dealership. The car was a courtesy vehicle, and was only put into service in 2009. Surprisingly, it's still under the bumper to bumper warranty for another few months, and...

www.clublexus.com

It would seem like this problem has been around for awhile, not being a "safety" issue among other things
wasn't addressed at the time...or didn't affect enough vehicles.

What's happening now seems different, they have made a change.
According to some its interim until the final design

 

Don't be surprised when Toyota issues a TSB to reprogram the system to reduce or eliminate the RF shield status shutdown. Would this harm anything other than the possible stray RF signal in the environment.

Oh wait, system shutdown due to unlocking the doors from a distance. I would hope that it would need to be more than that.

Or is it the other way around. Is the shielding protecting the environment from what is coming from this cable?

 

Is the shielding protecting the environment from what is coming from this cable?

Yes. There are limits, imposed by FCC, of how much EMI a device can "spill" outside. Those cables carry high currents, high frequency switching... so yeah, their RF noise needs to be contained.
Otherwise you would block all the cellphones and radios around you.

 

Thank you for sharing. The braided wire looks better than I would have expected for Syracuse but the clamp/collar looks like it will turn into dust in a year or two. Remember, the Car Care Nut said the Prime is not part of this but from your pics, it should be. I'd like to see some pics in a year or two of the open design and if it really makes a difference.

These cables never look pristine in salt areas. We all know Toyota's current policy so unless you're going to mess around with the cable, I don't see the point anymore in checking.

 

Just leave it, the braided wire you see is just the outer ground/noise shield that does not carry the power.
No need to worry unless your hybrid system stops working. Haven't heard of this happening yet.

Rx 400h - Ever see this before? - ClubLexus - Lexus Forum Discussion

Hybrid Technology - Rx 400h - Ever see this before? - I will be getting a 08 RX 400h tentatively on Saturday from a local dealership. The car was a courtesy vehicle, and was only put into service in 2009. Surprisingly, it's still under the bumper to bumper warranty for another few months, and...

www.clublexus.com

It is interesting reading, old postings 🤔

 

Damn, Toyotas and rusting, name a more iconic duo. I'm gonna check this on my 2021 Prime. Who knows. Maybe it's rusting out here along coastal areas too.

 

Has anyone removed the connector and apply CRC in their Prime? There are a couple people in RavH group who have done it to their Rav4H. The steps are simple enough, but I found that the "Service Plug" location in Prime is different than the one in Rav4H, and I am hesitated a bit to move on.

If anyone has done please chime in. 🙏

 

What would be the downside of packing the orange case fully with some kind of appropriate grease, so there would be no direct way for water and salts to get to the shield mesh?

 

1) Toyota might decline warranty (if they ever decide to extend their warranty to the part)
2) Dealer might deny to apply fixes (if Toyota will ever provide them)
3) If rust do develop under the grease, it'll be hard to detect

 

Here is a link to a Facebook group regarding the RMG cable rust issue. Many of the posts are in French but translate works pretty well.

Toyota CABLEGATE (Rav4 Hybrid & Rav4 Prime) | Facebook

Group dedicated to sharing information and promoting to TOYOTA CANADA and TOYOTA USA the acknowledgement of the High Voltage Hybrid cable corrosion issue for 2019-2022 AWD Rav4 Hybrid, 2021-22 Rav4...

www.facebook.com

[0]=AZUXxuuUcMWU4yc8Sncih0ZnrtKiBkuJx3Gs29LthuFDigzrmKByelOG41AJpV5t5Pcj31_CJz_1jJq6fmxZEAfxXMRZ6cu8K_dhA9jdl33w8Nd-kEruG-h3olZmX0c2QG1psUPiwuB_Q2k_b_SJSZiG1OIi6t7k5cyy5knj4aL6RGuKkqUmH0glOZme5o65qR-xkWLzGliP5zucvR3yf474&__tn=-UC%2CP-R

In Quebec where they have lots of snow and salt the roads the 2019-2022 RAV4 hybrid and Prime are having issues. Sounds like more than a few people have had to pay to replace the cable at $6000! This group is urging Toyota to extend the warranty for the the cable from 3 years to 8 or 10.

As previously mentioned you can test your Prime by turning on the AM radio and shifting from Park to D or R. If the radio gets static when shifted then Toyota will conduct an inspection of the car's cable.

 

THanks for the great write-up and photos.

I'm curious - which preventative are you considering. From the other post, it appears to be a competition between the cosmoline-like CRC or the ACF-50, which is more like a penetrating oil. Also - please do keep us updated regarding any feedback you may receive from Toyota.

Thank you again!!

 

Toyota inches closer to a resolution:

Toyota va remplacer les câbles défectueux sur les RAV4 hybride et Prime et ouvre une enquête – L'annuel de l'automobile

Toyota va remplacer les câbles défectueux sur les RAV4 hybride et Prime et ouvre une enquête – L'annuel de l'automobile par Benoit Charette. Toute l'actualité automobile regroupée en un seul endroit: Essaies routier, comparatifs, conseils et plus!

annuelauto.ca

 

and the English version: Toyota Investigates Corroded Cables in RAV4 Hybrids | Torque News

 

It is interesting in the above article the speculation of the actual cost of the cable. There is an entire aftermarket industry that specializes in making non OEM replacement parts that cost far less than OEM and claim to be functionally equivalent. Toyota has been running ads dumping on independent repairs and encouraging traffic to their service department. I would not be surprised that if this is ongoing issue that if Toyota elects not to do a campaign, that a replacement cable made by a non OEM group will pop up and that independent third parties will be glad to install if undercutting Toyota. No doubt give it few months and You Tube videos will pop up.

Lawyers are always looking for potential class action cases and this seems to be right up their alley.

 

The aftermarket fix is probably going to be a jumper for the sensor connection that closes the circuit and clears the code, or some kind of clamp connection that reestablishes ground to the shroud. The factory fix of replacing the entire wire assembly for a shield is about as crazy as replacing the whole engine because the ground strap went bad. If Toyota ends up paying for enough of this they’ll engineer a retrofit that salvages the expensive harness and just fixes the shielding wire. My guess anyway.

 

For me,,, the more I look at it, the more I think, " Disneyland Design" - AKA Micky mouse ~ as well as "the fix", by cutting a hole in the side of the cover - ( my 2022 has the " cut out" )
And why, "O" why, is it not, a waterPROOF connector in the first place ??

 

.