P1121 CEL-RTD and coolant spray

- #12. Yup you were right on. I quickly overlooked that drain valve from the get-go as i had replaced it with another mail ordered part; thought that loose end was behind me,-- apparently not bc it was missing an O-ring. Glad we relooked at that option.

- LESSON. Andrew you are correct i do have an incorrect understanding of both coolant systems. Re-looking at the schematic clearly outlines inclusion of the coolant control valve. Thanks for the direction.


- 3 CODES. CEL went away but day2 and 3 codes still there. I will def have another look at my hoses. I marked that top hose and seemed pretty thorough with breakdown and build up of coolant and coolant control valve.

- COOLANT BLEEDING. I bled both coolant systems at the same time. Refilled both reservoirs concurrently, but completed the engine coolant system first with the paper clip hack. Secondly, I tackled the inverter coolant system. After filling to full, i then doubled clicked the engine start button. Had the 1/4" tubing set up and the air-bubbles/fluid actually arced into the reservoir from the drain cock.

- REFILL VALVE. Sorry i think i meant to say radiator cap refill.

 

A day later this AM(17APR), upon inspection the engine coolant is stable from a 60 mile drive last night at speeds well over 60mph. Still no spillage into the engine compartment, definitely looks like the that valve O-ring was the culprit.

 

Still after visual inspection no issues. Confirmed the hoses have been sequentially returned to their original position. No leaks pooling under Prius from running errands this AM. I had the Prius at 65mph this AM for 5minutes as well. All looking and sounding good and appropriate. Rechecked the OBD2 codes same again--- p1118, p1121, p1150. The OBD2 machine is erasing the previous stored codes just prior to spitting out the new DTCs--- still perplexed.

 

Its a nice soothing and flowwy HUM at cold start and upon engine shut down. Been hot here at ~80sF, i will make that effort to hit the HEATER today. The AC is great though and ready for a Virginia Summer. The CEL self-removed from my upper dashboard 2 days after the coolant control valve procedure. Front dash is clean and empty. Yeah, kinda scared of false negatives as my OBD2 is still spitting out those 3 DTCs- p1118/1150/1121.

 

me thinks in a couple of weeks if the DTCs don't subside, i may consider swapping out coolant for the OEM pink.

 

Currahee- thanks for the option. I will let you guys know if this experiment with alt coolant pans out.

Andrew- yeah my OBD2 tool i got from Harbor Freight; been real good with the basics in getting me in the ballpark of diagnosis. But i think you see that i am ready for the next level of richer/robust diagnostics. The code reader always starts with a delete default and asks if you want to keep old codes; i usually delete old ones in order to get readings anew.

i am currently looking into the Mini VCI cable option. Sounds new and exciting. ; )

I just tried the heating system in the Prius. Its working real nice on this Virginia Spring day-- its warm to hot. Cant really test the system fully straining against a colder environment. Does it matter?

I'll def take your advice on the flushing, if i return to pink coolant swapping.

cheers.

 

The car is running GREAT. I forgot to mention of Prius performance from last i wrote..... accelerating and braking is back to normal; i noted last month when i was in it deep driving at less than <35mph, that i was experiencing slower response to acceleration pedal and braking high/earlier on the pedal. Im taking the car up to 70mph; so Im feeling pretty good with where i have the Prius. But those sticky 3 DTCs are still looming.

That HUM you mentioned = every once in a while I notice a short-lived humming (like a fishtank pump) emanating from the engine compartment usually after cold start and at gas-engine rest. I do recall that noise long ago; its that CHRS pump you mentioned.

Glad there was no overheating damage to engine--- lucked out.

thanks.

 

Engine efficiency is still good ~ 45mpg highway.

 

OK, its been a successful 14 months later (& 15,000 miles) and i decided to swapped out the green/yellow coolant for the pink stuff. The green coolant handled fine over the last 14 months. But the price for Pentafrost went down significantly over the last year to ~$10.