Yellow Brake Warning Light

OK, I finally got my Mini VCI and got it working. (Painful process - short summary is that it doesn't work on Windows 10).

The report shows several DTCs, but only a couple that are current and should be looked at:

One is something about the AC sensor in the dash and the other is C1377 - "Capacitor Malfunction"

Any insight as to what that might mean?

Evidently the capacitors are near the 12v battery in the back and are related to the regen braking. They also evidently rarely fail.

 

FWIW, here are all the codes present.

Oh, and the 12v battery was replaced about a year ago, I think.

We just turned 190K as well.

 

I have a new symptom. When braking while going very slow I get a lot of clicking noises, more than normal. If stopped and I press harder on the brakes I get a series of clicking sounds, same when I release the brakes. I need to pull new codes and see if anything has changed. I may start a new thread on that. There are a lot of brake clicking threads, but I haven't seen one that addresses my specific symptoms.

SM-T320 ?

 

OK, for those still following, today we got more codes and issues. Driving home, after a block my wife got the BRAKE, ABS & VSC lights came on and it beeped for 10 secs. She pulled over and called me and I told her to come straight home. It then beeped again and she continued home & exiting the freeway, about 10 miles or so later, the red triangle came on, the red car error light on the display and it began to beep constantly. Se also noted that the brakes were very hard. She pulled into a lot and at that time a red battery appeared on the screen and a message "problem". She shut the car down.

I came to pick her up and drove it in a short circle around the lot. Only the red triangle and red car on the display were on and it drove fine. We were only 4-5 miles from home, so I decided to try to get it home. No new lights and no odd symptoms on the way home.

I connected to Techstream and got the same codes as before plus P0A08 and C1241. C1241 indicates low positive battery voltage, and techstream indicated 10.8v on what I think was labeled B1 & B2. I checked across the 12v battery terminals and got 10.8v initially (and briefly) and then only about 8.6v. With the car on (Ready) I get a brief 13v then it reads about 11.3v. All too low. My 12v battery was replaced in Feb. of '14, a bit early for a failure. One cause of P0A08 is inverter failure, I'm wondering if that's the issue here. The fact that the voltage is higher with the car on, however, tells me that the inverter is working. Can this 12v be tested properly by a parts store like any other battery?

At any rate, it isn't really reliable to drive at this point so I'll probably get it into the dealer or another mechanic and at least have it diagnosed.

 

Thanks, I'm going to check all the the connections back there and take it out and take ti to a parts store for a check up.

Any thoughts on why I'm getting higher initial readings from my meter? I'm placing the probes directly on the battery terminals and the meter is set to VDC.

 

I checked the electrical connections around the 12v battery. The plug to the module next to the battery had some corrosion, which I cleaned up. I also checked the tank for the inverter and found that it was low. Significantly below the "low" mark, but not empty. I did not see any movement in the tank, but the level was low enough that it was tough to see. I plan on getting more coolant after dinner - maybe.

Of course, the dealer is closed and Autozone lists Pentosin Pentofrost A4 the right one for my Prius. Description:

Pentofrost A4 is a phosphates organic acid technology (phosphates oat); which is categorized as goat (hybrid organic acid technology) in the US market. Pentofrost A4 is suitable for all Asian vehicles using pink antifreeze/coolant. Pentofrost A4 does not contain any silicate, borate, nitrite or amine containing additives since these may harm your Asian vehicle. Do not mix with other coolants (especially silicates coolants), as this may cause gel formation and clog your radiator. Pentofrost A4 is a pre-diluted antifreeze for Asian vehicle applications in water-cooled engines. It contains phosphates and organic salts to protect all materials used in cooling systems for Asian vehicles. Pentofrost A4 is mixable with all phosphates oat’s. Meets ASTM D-3306.​

Thoughts?

 

The manual says SLLC or "any similar ethylene glycol based non-silicate, non-amine, non-nitrate and non-borate coolant with hybrid organic acid technology". Sounds the same, but this post has me worried, but that's a 2001.

 

Yes, car was "Ready". Engine wasn't running.

Waiting will make getting to work a challenge. If I can sort that out, I will. I don't want cause more trouble.

I'm curious why you said above that you think I may have to replace the hybrid battery? I have no battery related symptoms, it's always in the blue on the dash, no dramatic fluctuations, etc.

 

I think you're right, but I may wait until Monday to get the SLLC just to be sure.

Done. I get a reading of about 10.8v briefly, then it drops to 8-9v.

Done. Again, I get a brief 13.something volts then it drops to show about 11.3v.

I'm getting an improvement, but I'm not sure it's what it should be. I'm confused about why I'm getting the instant higher reading followed by a lower one.

I'll try your measurement to ground next.

 

I'm pretty sure the battery is toast, I now can't get into the trunk.

It's almost 10PM here, this now sounds like a tomorrow problem. Goodnight.