What Might Be Happening with these Warning Lights?

A few months ago I had the interior of my 2009 Prius detailed. Guy who did it left a LOT of water in the interior. When I started it to drive away, there was an array of lights on: the dreaded red triangle warning, steering light, and brake light. Had the car towed to my competent mechanic, but not Toyota since they're soooo expensive.

The mechanic kept the car for about a week. Lights would go on when first started, then go off. Error codes as follows: C1300, C1310, U0129. He finally said it was probably the brake module, but before spending $2000 to replace, he suggested I replace the 5 year old starter battery. Seemed to work fine for a few weeks.

Two or three times since, I have had a few other issues with warning lights. Twice I got the brake warning light. It went away after 5 and the 20 minutes or less. The last time I got the light, when it stayed on 20 minutes, I brought it to Toyota. By the time I got there, no lights were on. He said it could be low brake fluid. Nope he checked and brake fluid was fine. He said since the light was no longer on, diagnostics wouldn't show anything. He suggested possibly happened because there was a terrible storm in the morning.

Today while parked in a parking lot, I got the dreaded red triangle light, the ABS light, and the emergency brake light was on even though the emergency brake wasn't set. I drove a few feet back and forth, and the brakes did seem a little weird. But after about 5-10 minutes of starting the motor and turning it off, all warning lights went on. I drove home and all was fine. Braking was fine. Warning lights didn't appear again.

One more thing. Today, horrible thunderstorm early this morning. 10 hours later when going home is when the lights went on. The time before that when I got the brake warning light, there was also a horrible thunderstorm in the morning, and I got the warning light at the end of the day, 10 hours later. I don't recall whether it had rained the one or two previous times I got the warning light.

Does anyone have an idea what's happening? If I bring it to Toyota with no warning lights on, I think they're going to blow me off again.

 

146,000 miles. Where to find instructions on the voltage of the starter battery?

 

Oh, found instructions to check battery. On my way to do that now.

 

12 volt battery with no engine running 12.7 volts. With engine running 14.1 volts.

 

After the interior detailer left water all over the car, my mechanic took everything apart, including the carpeting and the battery compartment. All the wires under the carpeting were exposed. He left all of the doors and the hatchback open. It was left inside the mechanic’s garage that way for over one week so that everything could dry out. But only replacing the 12 volt battery made the lights go off. While the mechanic had it and before he replaced the battery, he would drive it every day. Lights would be on at the beginning every day, but go off after a while. Only after replacing the 12 volt battery did the lights finally go off for several weeks.

I think I got warning lights four times in two months since the battery was replaced. Always happened when starting the car up after sitting overnight or after it was parked in the parking lot where I work. I only remember that there were severe storms for incidents 3 and 4. I really don’t recall what the weather was for incidents 1 and 2. It was in the morning and it could have rained night before, but I just don’t recall.

All of the wires under the carpeting, of course are in those plastic corrugated tubes, so who knows if there’s corrosion. Don’t think I want to pay hundreds of dollars on a 10 year old car with 146,000 miles to check out or replace the wiring, only to perhaps discover that they cannot find anything wrong.

Before replacing the 12 volt battery, the mechanic said the codes show the brake module is bad. But if he replaces the brake module, we don’t know for sure if that will fix the problem. He says brake module will be about $2000. For that amount of money, I think I’d be better off getting a new car.

Was just hoping someone had something similar happen and could suggest a solution. It’s really unnerving to see these are warning lights. Everything else on the car works fine. Hate to trade it in just yet.

 

I’ve never had any water issues with my car. I take the mats out every week and wash them I see the carpeting underneath when I do that. It’s always dry. After the incompetent detailer was finished with my car, when I ran my hand along the carpeting on the back floor, water was pooling up along with bubbling soap. It was pooling in front as well. Not sure why he used so much water/soap since I can’t remember anyone ever even sitting in the back seat of my car, so it was immaculate. No question, what he did was overkill. I just wanted everything inside to be freshened up since the interior had never been shampooed before. After all, the car is 10 years old.

I had to have the car towed when he was finished because of all of the warning lights including the red triangle. The tow truck driver said sometimes disconnecting and reconnecting the battery will get the lights to turn off. The top of the battery was all soaked. He had to wipe it down. So was the whole back of the car under the hatchback. Funny, though, he forgot to shampoo the removable carpet. It was completely dry. He told me to bring the car back when I got it working and he’d clean the rear removable carpet. Again, everything under that movable carpet was immaculate, and he soaked it. It wasn’t wet in one spot. The entire back was very wet.

Since I’d never seen any warning lights previously, and when I got into my car, still inside his detailing garage, all of those warning lights went on when I turned the car on, I can’t help but think he caused it. At least, he caused the lights to go on that time.

I asked a Toyota mechanic about the codes that my own mechanic was getting two months ago when the saga began. He looked them up and knew exactly what they all meant. I don’t remember myself, though, this was 2 months ago. My mechanic said every few years, they will get a car situation where they just cannot figure out what’s happening. Mine was one of those cases.

Today is Thursday. The car has been fine since Tuesday. When I had brought my car to the Toyota dealship the previous time I got a warning light (not the same warning light as I got on this past Tuesday), they told me they can’t run a diagnostic on it when there are no warning lights on (they have always turned off after a while). Anyone know if this is true?

For what it’s worth, there have been plenty of days when it has rained, and I didn’t get any warning lights.

So I will order the scan tool, I guess, then try using it the next time I get the warning lights.

 

Researching scan tools. All seem to say it won’t give diagnostic codes for brake light and/or ABS light.