Sudden CEL and Turtle

[TeCKis300]

2012 here with 97k miles on the clock.

Driving on a long uphill with A/C on full blast, suddenly flashed a message which I didn't quite catch other than noting "overheat"... along with turtle light and CEL. Message on console then replaced by the generic message Check EV system and bring into dealership.

Throttle pedal quickly but progressively tapered off such that I couldn't even hold residential speeds.

I turned the car off and on. The generic message and CEL stayed on, but no more turtle light. I was able to gently drive the car home with seemingly no more excitement other than the CEL.

Searching, I wasn't able to find similar symptoms. Anyone have any idea? Thinking I should have the car towed into the dealership tomorrow, but I may tempt driving it? About 35 miles.

 

[miimura]

If you can drive it to the dealership on surface streets, I would go for it. If the only practical way to get there requires freeway travel, I wouldn't drive it, I would have it towed.

If it's really something overheating, you may have a coolant pump that's not working.

 

[TeCKis300]

Thanks miimura. That's what I'm thinking that it's the coolant pump. I had her in sport mode and was cooking up the hill pretty good when it happened.

The drive to the dealership is all freeway with some significant hills. Tow is free as I have premier AAA, so better safe than risk losing power on the fwy or overheating and damaging the batts.

Is there a way I can pull logs/status/codes myself? I very familiar with OBD-II and diagnosing ICE cars, but haven't really played with this EV animal.

 

[miimura]

It is relatively easy and inexpensive to get a Toyota Techstream setup installed. However, I don't know how much it can tell you about the Thermal Control ECU, which controls the pumps. The proprietary Tesla app and special cable is required for any detailed work with the pumps like starting the coolant purge cycle when you need to change the battery coolant.

 

[jgblair]

We had a similar situation. Ours was caused by a rat eating a hole in the coolant hose. It ended up being about $1,100 to replace the hoses and put coolant back in.

John

 

[dstjohn99]

Have you checked the coolant levels? If the DU coolant is low then you may have a seal leak inside the DU, which will lead to an electrical short and failure of the DU / inverter leaving you stranded. Or, as previously stated, there could be a hose leak. Either way a lack of coolant could cause overheating. If the coolant levels are acceptable then likely it is a circulating pump or chiller issue.

 

[TeCKis300]

Great input all.

I actually have a techstream for my other Lexus vehicle and am a pretty accomplished wrencher. Cursury check of all coolant levels were fine.

It's my wife's car and is still under warranty. Last yr of platinum 7yr 125k warranty, so I'm letting the dealer handle this. Had her towed down a week to date now. Curiously no diagnosis yet.

At least I convinced the dealer to provide a loaner, and we have a third car so there's no real urgency.

She did get a new motor about 8k miles back for the bearing noise issue.

 

[TonyWilliams]

If the coolant hasn’t disappeared into the inverter (usually causing a terminal failure of the inverter), then this issue is most likely a failed coolant pump.

There are three pumps on the car:

1) Cabin heater - this pump rarely fails, mostly because the duty cycle is to only run with cabin heater. You can locate this pump by opening the hood, and looking straight down, slightly to the passenger side of the vehicle.

If you turn the cabin heater on, you should feel warmth in the hose within about 1-2 minutes, and feel the pump spinning. It’s safe to put your hand directly on the hose next to the pump, and feel the vibration and heat.

Pink fluid (regular anti-freeze / coolant) will be seen circulating in the pink holding tank.

This is a super simple test for cabin heater failure, or pump failure.

2) Motor / Inverter pump - this is located near the cabin heater pump, but it’s easy to see underneath the car (after removing the plastic underbody panel).

3) Battery pump - this one is located at the rear of the “engine bay”, slightly to the passenger side, next to the battery heater.

If either pump 2) or 3) fails, the respective component gets uncomfortably warm, and power is limited / shut off, and the Check EV System light will come on.

We have the pumps in stock.

 

[TeCKis300]

Only 18 days later... and we finally have a diagnoses. @dstjohn99 likely nailed it.

Requires traction motor replacement. Digging in a little deeper, they're telling me that coolant leaked into the motor and onto the speed sensor causing the error message.

Am I correct to interpret this as coolant leaking into the inverter?

Either way, things should happen quickly now.