Hi everyone 2013 Prius 121K miles Got code p261B while driving @ 60mph on highway, engine light on and car refused to accelerate.during that time, coolent temp went from 194f to 212f and than back down to 198f. After engine off for 2hrs and cool temp 100F. I run engine on again and coolent temp went up to 121F and keep on to 149F even i have engine off during cool temp reach @ 121f Do u believe the thermostat problem rather than water pump? Or may be just the water pump roter problem Every thing has been maintained. From egr cooler cleaned to the pipe and Oil catch cans. Transmission oil to inverter coolent changed.
I think it's a few minute job to pull the water pump off and then before I disassemble it hook up the software call up the water pump see what the impeller looks like when it tries to spin or does spin then if it does not spin satisfactorily or extremely slow pull it apart and see the plastic rotor and impeller damage and then go from there.
Also do a quick check of your electric cooling fans. Turn on your AC, set the temp to low and make sure both cooling fans are turning. If one or both fans aren't turning - you can disconnect the power wires and jump them directly to a battery to determine fan or control issue. Hope this helps... PS. if that car has that electronic diverter valve, look at that too. It may not be sending coolant to the radiator.
What are the software to turn the water pump impeller? I guess it techscrem. disassemble water pump will wast 1 gallon of coolant without know the issue. Rather wait for part to arrive to be safe
Both fans are running with AC on. Torque reported coolent temp highter than usual. Outside temp @82f and coolent temp 100f even engine off for 2hrs
It's seems so rare that 90% when i pass by a section of only that highways to work and my coolant temp spike up to 212f. It slowly went down to 195f after a mile away of that section. Yesterday, the coolant temp spike up again and it gave a code 261B on frist time. Don't know is it electronic pole can cause water pump or rotor? Maybe cause electric problems
I had post couple weeks ago that the break, track control and tire pressure light keep turn on and cause the regeneration brakes turn off. Turn out low voltage in the 12v battery cause all this issue.
I have the generation too that's doing this right now but it does not have that code and it doesn't have an electric water pump and it is all working properly but the temperature still spikes there there's a small leak somewhere that I have to find a drip actually and even when the car's down say a mason jar full of coolant low when I'm getting on it on the highway the red triangle will come on and I'm positive it's telling me that my temperature is getting high and then it immediately goes off then it comes back on every few seconds what have you then goes off then comes back on so I'm not sure maybe the thermostat might be sticking possibly or the sensor might be going bad because the car doesn't really feel hot and it's not missing or acting up.
I suspect the area of the highway your talking about is a slight up hill requiring more power from your ICE. Your water pump isn't ramping up to keep up with the increased power demand. As soon as you crest the hill and back off the accelerator; the engine will begin to cool down. Bottom line, sounds like a borderline water pump issue. You wouldn't see this issue in the winter time under cooler weather, but as we get into the scorching summer - your issues will increase.
There are a lot of uphill & down hill on SoCal highway drive, but only on that section of highway cause coolant temp spike. Assuming my water pump can not be ramp up the demanding speed to move the coolant. Which means the water pump electrical issue or could be the pump old Rotor has some resistant.
I would change the entire assembly rather than split hairs between rotor and pump. The ECU ramp up signal isn't likely to be an issue, unless you've got rodents chewing on you wiring harness or your harness is rubbing body panels creating a short. That would cause temperature spikes and drop outs..
I took the water pump out and guess what?? The roter seized up and pull the impeller broken.See pictures
