Intermittent P1093 "manufacture specific" powertrain code

Hey guys, I am new to the Toyota Prius and just picked up a deal I could not turn down. I have 9 other cars and came across an opportunity to pick up a 2005 Prius with 176K on it for $475. The car was very dirty inside and out but I saw the potential and for that money, it was a no-brainer. The hybrid pack needed a cell and I have a friend with a business doing it, so we pulled the pack and fixed it. I have it all together, cleaned up and on the road. Everything works fine and it runs and drives great. However, one issue that I am having with it that I need some help tracing down is that I am intermittently throwing a P1093 code causing the red triangle, check engine and VSC lights to come on all of a sudden. It seems to happen after I go out and drive for a while from cold. I drive with my OBDII scanner hooked up and once it comes on, I clear it and most of the time, it will come back on fairly immediately. Sometimes within half a mile and other times within a few seconds. Once it throws it once...and I clear it...it seems to get into a rhythm throwing the code. Last night I drove around town on a bunch of small trips like to Lowes, parked for 20 mins, to Walmart, parked for 10 mins, and back home....and nothing ever came on.

I spoke to my buddy about it that has the battery business and also I talked to the dealer on a very high level. They want 110.00 to hook to the Toyota computer and run diagnostics because the real trouble is problem hidden under the generic P1093 DTC. I am determined to figure it out without the dealer if possible. I am extremely mechanical and I have plenty of OBDII experience and was a technician 20 years back...but not with the hybrids. My buddy seems to think that since there were some small water leaks in the rear of the car (I have resealed the body seams in the rear rain channels of the hatch) causing water to get down into the spare wheel well and a little in the 12V battery area, that perhaps the Hybrid battery computer mounted in the cell pack might be doing it. That might explain why the car needs to be more on the hot side for it to happen as well? He's going to give me another Hybrid battery computer and we are going to see what happens when swapping them out.

I was just curious if anyone has seen this code before intermittently happening. It is ONLY this code and nothing else. My scanner is not able to narrow the P1093 down and give me the real DTC. Just wondering if anyone reading this might have an immediate thought such as, YEP, you need to check X, Y and Z. Thanks so much to anyone lending an ear/opinion!

Chris

 

One thing to add to this that might factor in.....I have noticed that sometimes the cruise will engage when pressing the button on the end of the stalk, and other times it will not. Also, if I get it turned on, sometimes I cannot turn it off. I have read that this might be the clockspring in the column which makes sense since all electrical control of the wheel buttons goes through the spring. The recirc buttons on the lower right of the wheel are inop as well, whereas all the controls on the left of the wheel are working. Is it possible that this intermittent electrical issue could be contributing to / throwing this code?

 

Patrick, thank you for the response. I agree from the DTC/P1093 error code perspective. I will try and have it scanned with a different OBDII scanner to see what I can come up with. A buddy of mine has a newer scanner than mine, maybe that will work. I wonder even if I stopped in at an Autozone or somewhere like that who advertise free check engine light scans.....maybe their scanners would yield more specific data? I think it is unrelated to the cruise intermittent operation though as well.

As far as the cruise, I can press the button at different degrees of rotation of the steering wheel and get it to work. The steering wheel controls for the recirc and defrost modes do not work regardless. I am assuming a new clockspring will probably resolve all of that. Where is the best / most financially reasonable place to obtain a new assembly? Any idea?

 

I figured it out....used a new OBD2 tool and it was throwing a code stating that the inverter cooling performance was the culprit. Found my pump is not working. Installing a new one tomorrow. Far as the clockspring, I have an OEM one on the way that should be here tomorrow. Cheers to all the help!