Chronic Prius VSC and Park Error Messages

I have been having unending electrical problems with my 2004 Prius with 47,000 miles on it.

My most immediate concern is an incident that occurred when we drove north from our home in the San Francisco Bay Area. We got about 300 miles, outside Redding, when the VSC warning light came on. It has done this before with the local Toyota dealer claiming an inability to reproduce the error and just returning the vehicle to us “to monitor.†(See below.)

We called the local dealer to get the phone number and address of the Redding dealer. As we came of the Interstate 5 off-ramp, we stopped in traffic for the light to change, at which point the vehicle did nothing. It would not accelerate, we could not turn it off, nothing seemed to function for several minutes while we frantically waived other cars behind around as they came zooming off the Interstate behind us. After a few minutes, we were finally able to start it and reset the system according to the owners manual. Redding was having record high 100+ degree temperatures that day.

It did this to me once before four years ago, when the car was new. It stopped dead in traffic on a freeway off-ramp in traffic. At first the local dealer’s repair supervisor claimed never to have heard of such a thing. I finally came across the news articles about early 2004’s dying in traffic and the Toyota service bulletin that followed. The local dealer claimed to have reprogrammed the computer system. Although we have had many mysterious VSC errors since then, we did not have another catastrophic failure until this incident.

The Redding dealer replaced three ECUs, the hybrid vehicle, transmission, and power source ones. They tested it and we picked it back up, only to have the VSC code and the “Park lock mechanism abnormal – stop immediately†message come on the display screen just thirty miles out of town. They took it back, tested it for 200 miles without reproducing the error and gave it back to us. I drove toward home. The VSC warning came on again 150 miles down the road.

I then took it to the local dealer. They kept it for 2 ½ weeks claiming to be doing diagnoses. They put on about 150 miles, with the service supervisor taking it home at night, without repeating the error. The written recommendations were to keep driving it. If the codes came back to do a “wiring bypass†for $450 dollars, or a full replacement of the wiring harness for $5000+. They insisted that although the ECU replacement had been done on the hybrid component warranty, wiring between them was not covered and the general warranty had already lapsed, so this would be entirely my responsibility. I took it back, drove inland to Contra Costa County where the temperatures were in the nineties, and got the VSC error code again after 42 miles.

The dealer took it back, downloaded the error codes, then put it back together and told me to pick up the car. Again they said I should monitor it and record any error messages. When I brought up the possibility of the wiring bypass or possible necessity to replace the wiring harness, the supervisor was evasive and noncommital. Somewhere during these conversations he said that although they had contacted the Toyota factory for advice, they received little guidance.

Here are the codes from the repair reports.

Toyota Redding: "...PULLED CODES AND FOUND C2300, P3102 AND UO293 STORED..."

Local Toyota on first return: "FOU[N]D DTC P3102 & B2775 BOTH STORED."

Local Toyota on second return:

"FOUND DIAGNOSTIC TROUBLE CODES UO123 (LOST COMMUNICATION WITH YAW RATE SENSOR MODULE, UO124 (LOST COMMUNICATION WITH LATERAL ACCELERATION SENSOR MODULE), & P3102 WITH INFO CODE 582 (TRANSMISSION CONTROL ECU) ALL STORED. DID NOT CLEAR CODES AT THIS TIME."`

The message I get is that they have no idea what is happening or how to fix it, and they’d dearly wish I would just go away. High outside temperatures seem to be part of what triggers it. That would explain why the mechanics driving home at night don’t get the error messages, but I do when driving during the day when the ambient temperature is high. The car has damn near killed me twice. I am reluctant to give it a third chance. I could really use some help or information from anyone else who has had a similar problem and its resolution.

I’d also like to know if anyone has had success in forcing Toyota to take back a Prius under the California Lemon Law. I am beyond the mileage limit in the statute, but since this has been ongoing for five years, I may still qualify.

 

SUCCESS!!!!! Re: Chronic Prius VSC and Park Error Messages

Replying to my own question posted here (see original post first):

After getting no success from TWO Toyota dealers and their techs, AND their reported "no help from the factory," plus thousands of dollars in parts replaced at Toyota's expense, I gave up and went to the Luscious Garage in San Francisco after reading an article about them in the San Francisco Chronicle. They specialize in hybrids. Carolyn Croquillette is the owner. She can be reached at (415) 875-9030.

She appears to have correctly diagnosed and solved the problem. It was the "shift control actuator," remedied by replacing the "shift actuator assembly." She took the car apart and started unplugging devices controlled by the ECUs (a.k.a. computer) until she reproduced the error codes. That's a quick summary of 2+ weeks of investigative work and driving the car around by her. The Toyota folks apparently looked only at the wiring and replaced three ECUs. It apparently never occurred to them that the device sensors themselves might be the source, rather than the electronics to which they were connected. Duh!!!...

The part was $500+ from Toyota. She found a used one from a wrecker for $130. After replacing it, she put the suspected bad unit in her functioning Prius, where it failed again. Total bill including a $50 expedite fee for the part and California 10% sales tax came to $639. Toyota had proposed first running a parallel wire from some undisclosed source to the ECU at $500, to be followed by replacing the wiring harness at a cost of $5000+ (yes, FIVE THOUSAND DOLLARS+) if that didn't work. Neither of these in retrospect would have solved the problem.

I can't say enough about Carolyn. She saved us thousands of dollars and I am no longer afraid to drive on the freeway for fear of the car going dead. She is smart, resourceful, funny, ecologically conscious, explains everything she tries in layman's terms, doesn't treat the customer like an idiot, and is very good at what she does. Sort of the antithesis of every encounter I have had with Toyota with this problem.

If you have unresolved Prius issues and you are driving distance to San Francisco, forget about Toyota. Go to the Luscious Garage and save yourself time, money, and aggravation. Again, the owner/chief technician is Carolyn Croquillette. She can be reached at (415) 875-9030.