Check Hybrid System, P0A0F / P2111

2013 PIP, 191k

“Check Hybrid System” appeared while driving. I didn’t realize the engine wasn’t running or starting. Consequently, the HV battery ran down and the car shut off in Neutral and I had enough momentum to pull over. Had it towed home where it sits now.


Techstream shows P0A0F and P2111, 206 code for the former in the FF data.

Full explanation for P2111 says “Throttle Actuator Control System - Stuck Open”.


Reading related threads, my issue seems different to what other people have encountered. I enjoy learning about my [fourth] Prius, but I don’t think I’ll be able to solve this myself unless it’s something simple. I change the plugs and do oil changes and transaxle fluid changes, but not too much beyond that. Is there anyone in the Boston area that you guys trust or can recommend?

 

Thanks for that, Potorap.

I'm thinking that my issue is not actually specific to the Plug-In, and maybe more people will see it if it's in the Gen III section? Should I delete and repost? Or maybe a moderator can move it?

 

About 191,000 miles. I guess there are videos for cleaning the throttle body? I don't think I have ever worked on that part of the car. Since you're in Boston, maybe you can recommend someone to work on it in case I'm not able to clear up the problem? Given the P2111 DTC it does seem to be fairly likely the throttle body and not something like a hybrid system component failure, right?

 

After getting to the throttle plate I discovered there's fluid in there. Like kind of a lot. I took some photos, but they're not great. It looks to my untrained eye like more than what could result from condensation alone. My question is: How does a substantial amount of fluid even get in there?? Has anyone ever seen or heard of that happening?

 

Yes, the throttle plate is reasonably clean. I didn't have carb or throttle body cleaner so I just used a paper towel with some alcohol on it. I have cleaners, but they're over 100 miles away. I'll buy some more and go over it again.
What should my next step be? You mentioned making sure the ECU is reading the throttle position correctly. I have the VCI cable/techstream. What should I look for exactly?

 

I had the car towed to a dealership and they found the codes I found plus speed sensor codes from the front wheels, I think. I haven't paid them the $170 for diagnosing yet so I don't have the paperwork. They wanted to replace the entire intake manifold and put in new sensors, I guess. I asked the estimate and it was just north of $2k. I said, "Stop right there." Just to clarify, they did not guarantee the work they wanted to do would actually fix the car. Dealerships and me are like Lucy and Charlie Brown with the football.

When the tow truck came, the engine did start, although haltingly, and ran for about 15 seconds before shutting down with the "Check Hybrid System" message. I was hoping to keep the car going, but I'm ready to pass it off to Carvana or Car Max. But they won't take it unless it's drivable. Should I just bring it to a local independent garage? I'm starting to lose hope that's it an easy-to-solve problem.

 

Thank you very much, Eddie. I'll update.

 

I've ordered the OBD dongle.
I had the car towed from the dealer yesterday, and when I was waiting for the tow truck I started the car AND IT STARTED AND RAN with no Check Hybrid System message and no apparent problem. The tow truck took about an hour so I did this three times over the space of 45 minutes or so. Then when the driver came I told him he could drive the car onto the flatbed, which he did.
I had it towed to one of the most beloved shops on Yelp in the Boston area. Even if they can't find anything I'm thinking of having them replace the throttle assembly, because like you say the issue seems likely to be somewhere in that component. At a place like PartsGeek the assembly is around 200-250 with shipping. Unless there's a better place to order it from.

 

Sorry to bump this, but the epilogue is:

The guys at the independent garage (in Medford, MA) were (and are) really great. They replaced the throttle assembly and throttle position sensor and did a bunch of things they didn't charge for. Prices were: 358 for throttle assembly, 97 for throttle position sensor, 248 for labor. 746 out the door. That was on June 28th. I've now driven almost 6000 miles with no issue. Boo to the dealership all day. Love my 54 mpg average. 196909 miles, heading up to 300 or 400k.