P3191 and P0A0F/204

In Techstream, what is the significance of these highlighted items, trying to make sense of why the engine does not start and hoping someone can shed some light for me.
I've been troubleshooting a persistent issue with my grey Generation 2 Prius ever since I purchased it from a tow truck driver for $1,200 shortly after my accident in January 2023. The car had been sitting for nearly a year due to registration and operability issues, and I’ve been working on getting it back on the road for the last few months.

Recently, I've been dealing with error codes that have been particularly challenging to diagnose and resolve. The primary issue seems to be centered around the P0A0F/204 error code, which indicates an "Engine Failed to Start." Additionally, I received the P0125 error code, related to the Engine Coolant Temperature Sensor, and P3190, which indicates "Poor Engine Power."

The car shows symptoms where the RPMs gradually increase for about 10 seconds after starting, and then it shuts off, triggering a red triangle warning light. The engine doesn't seem to rev up properly when the gas pedal is pressed, which led me to believe that the throttle position sensor might be the culprit.

I've tested and replaced several components to pinpoint the issue:

1. Throttle Position Sensor: I initially replaced the throttle position sensor with one from a dismantler, but the issue persisted. The RPMs kept climbing without regulation, and the engine still failed to start properly. I recently cross-referenced Toyota part numbers and found a throttle position sensor at AutoZone that matched my research. However, even this new sensor didn’t align with the specifications outlined in the Toyota Tech documentation I have. The readings from this new sensor were also out of spec, leading me to question whether the issue lies elsewhere.
   
   
2. Engine Coolant Temperature Sensor: Since the P0125 code pointed to a problem with the engine coolant temperature sensor, I checked the resistance and manually bled the system again, hoping to resolve the issue. However, this didn’t make a significant difference in getting the car to run.
   
   
3. MAF Sensor: I also checked the MAF sensor by taking it off and testing it with some power to ensure it wasn’t the problem. The MAF sensor checked out fine, which left me more convinced that the throttle position sensor or something related to it was the root cause.
   

Despite all these efforts, the car still refuses to run properly. I'm beginning to suspect that there might be something more fundamentally wrong with the vehicle. The throttle body and sensors I replaced had markings from a dismantler, which could indicate that someone else had already tried to fix this issue before and failed. This makes me wonder if there’s a deeper problem with the car's electronics or some other component I haven’t yet considered.

The frustration lies in the fact that no specific error code is being thrown to indicate precisely


any guidance is appreciated.

 

does this help any?

 

here are the others I grabbed with the first image I posted

 

Understood... I'm realizing now that I have to save the data after starting the recording in techstream before I proceed to put the car in Ready mode to record everything to nail this down. I tried replacing the ECM thinking it was bad and tested the resistance to all of the sensors since P0A0F/204 diagnostics says to clear relevant dtcs first.



i need to go back and check the dates of each of the data points ive saved, the realization that under DATA LIST the DATA 3 has the data from the one recording of the car that I did. The others in OPERATION doesnt have that detailed data. You see, im realizing
P3191 or P3190 were the codes returned plus the linear offset one I wasnt worried about yet. the only sensor whose resistance didnt match the standard was the throttle position sensor. the brand new sensor at autozone read just like the replacement from the dismantlers where only 2-4 and 3-4 was not 1.8 and higher. I plan to go through and check all sensors once more... its just... trying to track this down has taken wayyyy longer than it shouldve and hoping by recording something could help pin point this. hence my ask of what is the significance of the highlighted mustard color values in the techstream app?

I went to look at the file I did record, and did a screen capture... does this help you identify where this problem could reside and if not, where in Techstream would you recommend I start from other than the codes? Id like to like there is a blazing indicator somewhere in this app to monitor what is triggering this DTC... right?

 

Roger that ghostrider! I need to get back to the car so I can record PIDs from Engine and ECT.

Why on earth the car just doesn't throw a DTC for the problem is beyond me!

 

If AI is involved, it might as well fix the problem after it diagnoses the issue!