Red triangle and hybrid warning light, and Check engine light illuminated! Please help!

Thanks again, Patrick.

Chap, that sounds like a method of coolant change that I would like. Did you do it yourself?

Bob, will you please explain how to blow air through the system? I do have an air compressor.


And to all, could a lack of turbulence be causing my Prius to shut off? Or are the shutoffs related to the throttle body and MAF sensor? Or could a bad fuel pump cause the shut offs? The seemingly random shut offs seem odd to me, how when I hooked up the charged battery, Prius started and ran for the couple minutes I had it on, and how it ran the first time mechanic started it, but shut off immediately after the second start.. (no turbulence each time)..

Over the course of this week, I will have time to work more on my Prius, so I will keep posting updates.

Thanks, yet again for your input, y'all! (yes, that is my MN speech dialect coming out in type)

 

1. Coolant is pink.
2, 3, 4, 5, 6: OK.
7. No, I did not drain coolant before trying to bleed the system. I will do so before continuing to address the coolant loop, and post my findings.
8. I'm using the Toyota SLLC, it is pink in color.

Chap, when I tried the method of bleeding you suggested, I had the hose from the passenger bleeder going directly into a jug full of coolant on the ground. Would this have had an impact on the ability for the process you suggested to work, and even though I had flow going into the jug, being there was no air in the line when I opened the bleeder is the fact that I did have flow into the jug any indicator of the systems health? For example, if I try your suggested method with the line going from passenger bleeder to an open pan on the ground, if there was then no flow, would that indicate a problem? If that at all makes sense...

 

Well, I have now finally had time to take a look at my Prius again and work on it!

I cleaned both the throttle body and plate, and the MAF sensor. I was unable to detect any dirt on the MAF sensor, but the throttle body and plate were clearly dirty, with brown gunk in the body and on the bottom side of the throttle plate, as well as gunk creeping around onto the top side of the throttle plate. After cleaning all of this out from the throttle body and plate (I ended up partway removing the throttle body from the engine to get all of the buildup cleaned out), and cleaning the MAF sensor, my Prius fired right up, and stayed running! All of the warning lights still were on, so I turned it off to do the restarts necessary to clear the lights. The second time I turned Prius on, all of the lights besides the CEL turned off, and again, it stayed running. I left Prius running, turned it off and on several times, etc, to check if the shut off problem was resolved.

It became clear that cleaning the MAF sensor and throttle body/ plate did indeed clear up the shut off problem! Thank you for the advice on that!

Despite the shut off problem being resolved, there still was no turbulence in the reservoir. So, I drained the fluid, flushed the system using more fluid, and refilled it. The coolant that came out appeared to be clean, with no obvious signs of sediment.

After going through the bleeding process, I was able to get some turbulence going. When I began, the pump was very noisy, then throughout the process, it quieted down to the "aquarium pump level" by the end.

To get the air out, I massaged hoses and drove up and down the road I live on. The procedure I ended up following was:

1. Run hoses from both bleeder valves to reservoir.
2. Open passenger bleeder, close after ~30 seconds.
3. Turn ignition on, open driver bleeder, massage hoses, close after ~45 seconds. Remove hoses, put reservoir cap on.
4. Drive down road about 1/2 mile on gravel, come back and shut car off.
5. Repeat steps 1-4.

When I finished on Saturday, the front of the reservoir was about 1 cm higher than the back, and looking from the side, I was able to see vertical movement in reservoir. There was no bubbling, but clearly there was movement. At this point I happily declared victory.

The next day (Sunday), I took another look at the reservoir with the ignition on and pump running. There was no turbulence, and the coolant level in the reservoir was the same throughout. Perplexed, I parked Prius back in shop. Then on Monday, I tried more bleeding. I went through the routine a few times, and each time, a bubble about 2 inches long came out of the driver bleeder. I was able to get the level in the front of the reservoir about 1/4 cm higher than the back. Turbulence was low to non existent. I called a couple of Toyota dealers; they said it should be fine. One employee I talked to thought there were valves that open and close, so there doesn't need to be constant flow in the reservoir.

Perhaps as an aside, before I changed the coolant in the inverter and bled the system, Prius was in a heated shop for about 2 weeks, where the temperature was a minimum of 45* F. The day after I bled the system and checked it, Prius had been sitting outside, where temps were down to about -15* F. Perhaps the cold weather coagulated fluid in some already partially blocked hoses??

Unsure of what I should do, I decided to drive Prius locally, and continue to monitor situation. On Monday, I drove about 10 miles without incident. Temps were about -5*F. So on Tuesday, I drove Prius about 5 miles (temps ~-5* F). I arrived at my destination without incident. Several hours later, I began driving back home (temps about -15* F). After about 4 miles, the hybrid warning light, exclamation mark triangle, check engine light, brake light, and more lights, all came on. I stopped, left Prius running, popped hood and got out. Outside, I could hear loud fan noise from the hybrid battery vent, with air being blown out. Under the hood, I could see no leaks, and observed a lack of turbulence in the reservoir and the same level throughout the entire reservoir. Level was around full mark. I then shut Prius off, waited a bit, and started it back up. The hybrid warning light, CEL light, and triangle exclamation light all remained on; all other lights shut off. Due to the extremely low temperatures, I decided I was not going to call a tow truck, and slowly drove the remaining mile home. I parked Prius in shop, and decided to check the battery voltage. With everything off, voltage was about 10.5V. Prius turned on, 13.5V. Prius off again, 11.5V.

At 3:30 am following New Years celebrations, this was all I did before heading inside. I now have a generic OBII diagnostic tool on the way, so hopefully I will be able to pull some codes.

If you have made it this far through my long winded description, what suggestions or ideas do you have?! Again, thank you in advance!

 

I took a look at Prius again this evening, and did a DTC scan. When I turned the ignition on, the only dash light still on was the CEL. Then, after about 30 seconds, the ABS light came on. The codes I pulled were P3191 (again), and P3013. Tomorrow, I plan to check the throttle body again. If it has buildup again, could the PCV valve need replacing? I have battery charger going now. Battery voltage was climbing while charger was on. Thanks for the help!!

One thing that I forgot to mention: on Tuesday, on the same trip the warning lights came on, I had noticed that the regenerative braking felt somewhat stiff. Is this typical in cold weather?

Yes, very perplexing that turbulence wasn't maintained. I had the bleed valves out when I was bleeding the system. They appeared to be in good condition, and I had them on tight. When I looked at hoses with a light without removing anything for integrity inspection, I didn't see any obvious signs of leaks. What should I be looking for on the hoses? I also didn't see any leakage on transaxle or inverter, again without removing anything.

I'm quite certain that all lights have been off... Following lengthy bleeding sessions, I'm not surprised that voltage is so low, as since being bled, 20 miles total had only been driven.

Codes are listed above.

Thanks y'all!

 

How can I check both of these items? When checking spark plugs, on the Prius can I just remove them one at a time, put cover back on spark plug, ground plug, turn car over and look for spark?

Oh no!!

One thing I noticed, yesterday when I was looking at the MFD, battery level was 80%. Also, I checked codes three times yesterday. Before starting, both codes were present. After starting, P3191 only. Rescan, both codes again.

Thank you!

 

Thanks for explaining the process!

Ok, so now for an update. I checked on Prius today. Battery charged up, voltage was 13.05V when I unhooked charger. For some reason, my charger doesn't work when battery cables are hooked up, so I unplugged connectors from positive terminal while charging. So this being said, all of the codes and warning lights were gone/ off when I started up Prius. Prius successfully ran, I shut it off after about a minute. When I checked the reservoir, there was movement again! And the front part was about 1 cm higher than the rear.

I also checked the throttle body and plate. It was clean in there. And the pool of oil that had been in the bottom when I cleaned said items was gone. There had been a pool of oil below the throttle body, it looked about 1/16th inch deep. I never mentioned the pool as some posts on PC indicated this was relatively normal.

After observing all of this, I decided to go for a test drive. Prius drove well, i traveled a distance of about 40 miles. Still no warning lights. When i got back, voltage was at 12.85V. There also was still movement in reservoir, with front 1 cm higher than the back. Still no codes. Temps during drive were 10* F.

Later today, I drove Prius another 40 miles, successfully. No warning lights came on, and when I returned, there still was movement in the reservoir, with front 1 cm higher than back. I didn't check battery voltage, or if any codes were stored. Temps were -2 to -4* F.

Having successfully driven the Prius 80 miles with turbulence and a step in reservoir and no warning lights, after charging the battery, here are my thoughts. Following bleeding the inverter, 12V battery voltage was drained. Prius never really had an opportunity to fully recharge battery. Then, the extremely cold weather made the already low battery perform even worse, preventing the inverter pump from working properly, and eventually triggering DTC's. I forgot to mention, on Saturday night, on my short drive home (same drive that the warning lights all came on), my radio was not working properly. It was producing an extreme amount of fuzz, that was all I could hear. And before lights all came on, I had noticed that the MFD seemed dimmer than usual.

In regards to P3191, could that code have been stored in the computer from the previous no start dilemma? After cleaning MAF sensor and throttle body/ plate before, as mentioned, all lights including the CEL did turn off. How about P3013, could low 12V battery voltage have triggered this code?

What are your thoughts, all? Besides charging the battery, I haven't completed any work on Prius since my last post. What should my next steps be, and things to monitor/ check at this point? Should spark and fuel delivery still be checked?

Thanks again!!

 

I checked voltage this afternoon, after Prius sat overnight. Here are readings:

-12.21V with only trunk light on
-13.85V while running
-12.59V after running for five mins, temps -6* F
-12.36V after sitting five minutes with only trunk light on
-Hybrid battery SOC (from MFD) 50%

Temps had dropped to about -15* F overnight, I checked voltages after Prius had been sitting for 17 hrs outdoors with EBH plugged in for several hours in morning and early afternoon. When I ran and drove Prius a short distance for the said five minutes, the radio was intermittently fuzzy, so much so that at times that was all I could hear. I've never experienced this before, except Tuesday night before warning lights all came on. When I started and drove Prius during the five minutes, the orange turtle light was on the entire time, despite the blue temp light going off after about three minutes. The orange turtle light was also on Tuesday night, for the entire trip in which the warning lights came on. Tuesday night, on the way to my destination, the orange turtle light had been on for part of the trip. In all instances, I responded as the manual directs, and did not accelerate hard. What temps does the orange turtle light usually come on at?

I'm unsure when the spark plugs were last changed. I'll replace those next. Would that be a good time to replace the PCV valve also, or can they easily enough be accessed without removing windshield wipers, plastic shroud, etc?

In regards to P3191 being present when I checked DTC's, before I pulled codes, the battery had not been unplugged. So, even though the check engine light had turned off on its own following cleaning of MAF sensor and throttle body, could the code have been stored, then showing up when I checked the DTC's? Or could have low 12V battery voltage have triggered both P3191 and P3013? When warning lights came on Tuesday night, Prius did not shut off on its own.