Prius has been sitting in the garage for several weeks -- it is bone-chilling cold here. I went out to start it up and begin packing it. Noticed "Check Engine Light." Connected my OBD-II scanner. Got Code P261B which indicates a "Coolant Pump 'B' Control Circuit Range/Performance" issue, Cleared the code. Turned off the ICE. Restarted. Code has not returned with engine running for an hour. I was planning on a 2,000 mile trip starting today. Would you be worried or is this a common one-off? Thanks!
I would be perfectly confident to make a coast-to-coast road trip. There is always some minor roll-of-the-dice chance that any roadtrip could result in a breakdown. Such is life.
While a breakdown is always possible, I think the OP was concerned about the engine coolant code that got thrown (check engine). The question is given the environment (extreme cold, car sitting for several weeks), code gets thrown, gets cleared, and doesn't return in an hour, whether the code was probably a glitch or is a probably legit and something to be worried about on his trip. I don't know the answer to that, but I bet someone here does.
How many miles on her and has that electronic coolant pump ever been changed along with the OEM coolant change interval. You should probably monitor coolant temperature during your trip; so you don't end up popping a head gasket.... Good Luck.....
Why is it that so many people think clearing codes is the most immediate action to take once CEL illuminates? The car is perfectly capable of clearing the code itself if you fix the issue. I would try to postpone the trip for a couple of days and take the car out for a long drive first to see if the code returns. During the drive, continuously monitor coolant temperature. Most obd scanning apps are capable of monitoring that parameter. 2000 miles with that code in the back of my mind? Hell naw!
What was the voltage of the [nominal] 12-volt battery after "sitting in the garage for several weeks"? If you're lucky, low boot-up voltage confusing the computers might explain code. Otherwise, having either coolant pump die during your trip wouldn't be much fun.
Left before getting these replies. Drove 13 hours straight. No codes no issues. Drive included the Allegheny Plateau so hard on engine. Had to drive around North Carolina to avoid deep snow. Bone chilling cold means 7 degrees outdoors and probably 15 in the garage. Coolant serviced at recommended intervals, pump never replaced. With these additional data points, do you think I can breathe easy, and figure code was an anomaly?
Your data points are kinda irrelevant, since your driving in freezing cold. It's a fairly economical engine that will self cool when moving below 70F. Just because you crossed the Allegheny Plateau in freezing weather doesn't mean your out of the woods. Did you monitor your ECT while you were doing that climb; because your temperature lamp doesn't light up until 248+F, nominal is 180F-210F. Your car might hit 210F on that climb, if it was 100+F with your AC going. I'm assuming it was cold when you did that, running your heater to remove more heat. There's been many reports of the electronic coolant pump getting lazy and or intermittent past 120K miles, I'd certainly look at it before it does some major damage to the motor. Many just install a temperature gauge or monitor it through torque app. It's a silent killer and you've got your first warning. It's your car, do whatever you want. Just don't be surprised if it blows up on you..... Just saying......
My concern about the engine water pump is that it is what makes the coolant move. When the coolant moves, it can carry engine heat away from the engine, to the radiator and cabin heater. Just as importantly, when the coolant moves, it evens out the temperatures between different places in the engine. And it makes the coolant temperature reading (the sensor is just on the head where the coolant comes out) an accurate picture of the temps inside the engine. When the coolant doesn't move, it does none of those things, and your engine temperature reading is just telling you how hot a particular corner of the cylinder head happens to be.
