Overheating, radiator fan not working, and exclamation mark sign on HUD

So a weird thing happen yesterday...

I am driving smoothly on the highway, doing about 60km/hr, with my A/C working on a full. Suddenly, the check engine and emergency brake light comes up on the HUD along with a beeping sounding. A pull over, and smell a bad odor - like burning rubber - coming out of the hood. I checked and the car was immensely heated and there was smoke rising from a small rubber tube right next to the fuse box under the hood. I turned off the car.

Whenever I would turn the car back on, the smoke would start coming back. I checked several times. I couldn't find out where the smoke was coming from.

When the car cooled down a bit, I checked the radiator. The coolant level was a bit low so I filled up with the water. I also noticed that the radiator fans were not working, even when I turn the A/C on. So I called a towing company and got my car back to my garage.

Now the car heats up after running for a bit and the big exclamation mark sign comes on. The check engine light also comes on. But when the car cools down, the lights go away. I am thinking that the problem has something to do with overheating and the radiator fans not working.

Any ideas what should I do?

 

Thanks Patrick. I checked the coolant reservoir, and it was indeed the inverter pump which had blown. It was a very hot day in here (42 celcius) and it might have lead to the blow up. Plus my prius has around 90k miles on it so the pump may have just worn out.

I checked the coolant level in the radiator and it was not full. I was able to add about 1/2 litre of coolant in the radiator right after I returned. But when left overnight, there was no further depletion in the fluid level. I think the fluid might have evaporated after the car was overheating after pump failure.

I have taken out the pump and bought a new one from a local store. I plan to install it later today. Please check my message.

 

I just came back from the fitting. The inverter pump is in place and working fine. I can see bubbles and rubbles in the bottle connected to the inverter when the car is on ON mode. I put the car in ready mode and it seemed fine. All equipment is working as expected.

However, the check engine and the triangle lights are still on the HUD. I thought that once the inverter would be connected the lights would turn off automatically; but they are still on. I am nervous whether I should drive or not. Any ideas?

All the fuses and relays are enact. The radiator fan is working when AC is turned on.

 

went away like a charm.... thanks!

 

The car was running fine. For the past 3-4 days, problems have begun again. After 10-15mins of city driving, the big exclamation mark comes on the HUD, sometimes accompanied by the thermostat symbol on the panel. The exclamation sign lasts from 1sec to 30secs, and automatically goes away. I have checked the inverter pump, and it seems to be working fine (turbulence in liquid on car ON). I also checked the radiator fans and they are working fine as well. I have also noticed mild reduction in acceleration of the car, specially at higher speeds (50m/hr +). I am in a fix to what is going on. Any thoughts?

 

Checked. It's full in both the radiator and the access fluid reservoir.

 

I got the codes read and the car had two errors: Transmission Control and Inverter Pump. Both the codes were removed. The mechanic said that sometimes the codes are stuck in the system and clearing them helps.

But I am still getting the exclamation mark error. The error comes after around 10-15mins of driving, and usually when the A/C is on. The error usually remains on from a few seconds to a couple of minutes and then automatically goes away. The sign is accompanied by a thermostat sign on the screen.

The engine coolant was replaced around January and is in clear condition. Coolant in the extra reserve has been depleting but very slowly. There are no signs on dripping or leakage on the underbody of the engine. I checked both fans, and both are working and pushing air towards the engine. The coolant level in the inverter pump is also full.

Another thing: when the A/C is running, condensation appears on the A/C pipes leading from the radiator unit and into (somewhere) towards the engine. The condensation is so dense that it sometimes drips as well. Could it cause the error?

My mechanic is at a fix. Note that there is no authorized prius dealership in where I live. Also, the temperatures are around 95 degree (35 Celcius).

 

Patrick, when should I check for the temperature of coolant in the radiator? Right after starting or at the time the error appears?

 

Thanks for the detailed post.

1. I have been checking the coolant level in the reservoir since I last replaced it (which was in January). The coolant level in the radiator is always full. And it is always a couple of quarts low in the extra reservoir. This had been the case even before the current problems began.

2. Just checked, the coolant level in the radiator was full. The reservoir needed about 3 quarts (700ml) to fill.

3. Both radiator and reservoir filled again.

4. Checked the engine oil level. The level is up to mark on the dipstick and appears in a clean healthy state. The oil was replaced around 500 miles ago.

5. So I tried doing this. Even at the maximum temperature on the climate control, the A/C is throwing out cool air. Is it supposed to churn out hot air? I think this is because the temperature in the cabin is higher than the max temperature possible on the A/C. Is there a way to force A/C throw hot air? Or would this trick work even if A/C is on cool air?

6. Can you please guide where is the engine thermostat outlet?

7. The inverter pump appears clean. This pump was replaced a few weeks back as well. Is there another pump that I should check?

8. Should I worry about the condensation?

9. Thanks.

10. Where can I find the thermostat? Is it possible to replace myself?

 

My bad in the calculation. I meant 2-3rds of a quart. (about 600 ml).

I routinely check the reservoir. Last I checked was about 2 weeks ago.

So this is what I did this evening: I drained the coolant in the radiator and refilled it with coolant. While refilling, I kept the engine on READY and with AC running, and kept pumping the radiator hose going into the engine. I was able to get a lot of coolant in the radiator - I think about over 3 liters of it. There was a lot of air bubbles coming out of the radiator lid. All this process took about 15mins during which I kept the engine reving and kept adding the coolant. After about 10mins of AC running, hot air started to blow, so I think the A/C is working fine. When I last filled the coolant, I was only able to add around 1 liter. I was surprised that time as well as very little coolant was added. I think now there is adequate amount in the system.

I also took one pipe out of inverter pump and drained a little bit of coolant to take the air out. I don't think there was any air in the inverter pump.

During this entire process, no warning lights appeared. I drove the car for about 20mins with AC soon after. There was still no light. I hope this permanently fixes the issue.