Any recommendations for Gen I Mechanic near Ann Arbor, MI?

I'm new to this group and hoping for recommendations for a mechanic near Ann Arbor, MI who is honest and has expertise in Prius Gen I.
We bought a 2002 with 130K miles 2 years ago. It now has 142K and its first problem (possibly major...) Yesterday morning, in rainy weather, the theft deterrent alarm went off. At first it was intermittent, then it started going off consistently. After locking the door and waiting for the system to arm (30 seconds of solid red LED), the LED would flash for 5-10 seconds and then the alarm would go (beeping horn, flashing lights.) As long as the doors aren't locked, the alarm doesn't go off.
After studying the electrical diagram, I was planning to check the door lock sensors. However, I read something on this forum that indicated it might be a problem with the 12V battery. I decided to hook another 12V battery up in parallel and see if the problem went away. It did not. I drove the car about a block and then the real trouble started...MFD: PS + main battery + ! triangle. Also lost power, but I was able to limp back home.
I do not (yet) own a ScanGauge II, so I want to take it to someone. Dunning Toyota is near me and I'm also considering AutoMotion. Any suggestions?
Thanks!

 

Thanks Bob. I appreciate your prompt advice. I'll try to learn more about the Mini VCI. It looks like there are a bunch of options on eBay, but I'll need to sort out the version/compatibility puzzle. I have Windows 7, so I hope to find a scanner that works with both a newer computer and an older Prius!
Based on the recommendation of ACDC, I have an appointment with ArborMotion for next Wednesday. I presume that I'll need to get it towed the 5 miles from my home to the shop, correct? Or is it okay to try to limp the car in?
Thanks again,
Steve

 

Thanks Bob. The shop recommended towing, but I think I'll order a scanner and postpone my shop appt. until I am able to read the codes. I'll try the MiniVCI, since they practically give them away on eBay. I'll either set up a 32-bit virtual machine on Windows 7 or borrow an XP laptop from a neighbor.
I'm HOPING that I just had a low 12v battery condition that caused the various computers to lose their minds. You made a good point about not testing with the batteries in parallel, so I disconnected the Prius 12v battery and hooked up my spare Optima. Problems persisted, but I had used jumper cables to hook up the Optima to the small terminals, so it was still less-than-ideal test conditions. ; )
Anyway, today I took the Prius battery to O'reilly's and had it charged/tested. It checked out okay, so I reinstalled it. At that point it read 12.3v. Then I tested the Theft Deterrent System. No (false) alarm condition! Next I started the engine. No warnings or check engine light! Checked the voltage at the battery: 13.8v (charging!) I drove it around the neighborhood at low speed. Just after I put it in P, the motor turned off before I touched the key to turn to turn off the ignition, so I put it back in D and drove around more. I mostly kept it below 15mph, so that the ICE didn't kick in. I probably drove 1 mile total. Parked it and checked the battery: 12.7v. An hour later: 12.5v. I'll continue to monitor it.
My fingers are crossed, but so are my eyes...I don't know what caused the low voltage problem in the first place, or why it manifested itself in consistent false alarms by the Theft Deterrent System. It was raining, so I suspect a short. If it was a short in the door locking system, that might explain the false alarm symptom.
Anyway, I'm off to eBay now, to invest $25 American in a MiniVCI. Thanks again for the help!
Steve

 

Actually Bob, I think the 12v battery was replaced in early 2011, about 10 months before we bought the car. I had a pre-purchase inspection at a Toyota dealership. I think they mentioned that their records indicated a recent battery. The carfax doesn't mention a battery replacement, but it shows an electrical inspection in January 2011. I may end up swapping the battery, so it's good to know about the terminal modification.
However, it looks like I have bigger problems than the 12v battery... I drove the car again; less than 1/2 mile. Right as I shifted to P, the warning screen came up. I tried to pretend I didn't see it, and proceeded to raked leaves for an hour. When I got back in the car, the screen was there and the car wouldn't start. Battery was at 12.4v. Disconnected the negative terminal for a few minutes, then reconnected and everything was hunky-dory. Drove home without incident.I ordered the Mini VCI on eBay. I also found a guy near Detroit selling an Actron CP9185 Code Scanner. Do you have any experience with that scanner? Any idea whether it is "Prius aware"? (Do you like how I just throw that term around, as if I know what it means?)
Stay tuned for another exciting episode of Steve is in Denial.
Thanks!

 

Thanks for the clarification Bob. I'll look into the Actron (actually CP9175), but will plan on the Mini VCI.

 

Good news! (So far...) The problem was apparently a dirty throttle body. I took the car to the dealership, as they had a coupon for free diagnosis. On the way there, the car twice went into limp mode. I just disconnected the battery terminal to clear the condition, so the car arrived without any codes to read. The technician had to keep the car overnight and drive it in the morning, in order to get the condition to occur again.
The codes were:

• P3191 - Engine No Start
• P3101 - Low Engine Power

Technician recommended cleaning the throttle body and, if that doesn't work, check the fuel sending unit in the gas tank. This does not explain the earlier Theft Deterrent System false alarms, so the assumption is that it was a coincidence, caused by a low 12v battery.
One thing I hadn't mentioned previously: The car had been to the dealership a month ago. I hit a nasty road hazard that cracked the secondary (upper) oil pan. Both oil pans had to be replaced, to the tune of nearly $1K. I find it odd that both the Theft Deterrent System problem and the Throttle problem occurred nearly simultaneously, during the first heavy rain storm after major service. The dealership sees no possibility that these things are related, but it's hard not to think there is some common cause element.
I'll continue to wonder about that, but will knock wood and hope for no more codes. I received my Mini VCI today, so after a "tech surge" to put an XP virtual machine on my laptop, I hope to be more self-sufficient soon.
Thanks again for your help Bob!
Steve

 

Hmmm....I just researched the P3191/P3101 combination. Seems overfilling the oil can cause oil in the throttle body, resulting in my exact symptoms and codes.
When the Service Manager initial proposed cleaning the throttle body, she was going to charge me $135. I declined, saying I wanted to do my own research first. When I picked up the car, she said they went ahead and did the cleaning anyway, free of charge. I'd like to think she did it out of the goodness of her heart, but I wonder if it was a CYA, as she realized that they had overfilled the oil after replacing the oil pans.
I love a good conspiracy theory!