Problem with 12 Volt Battery in 2016 Prius 4 Touring

Automotive evolution.

 

@alanclarkeau , all these codes are simple Toyota tests to check you're keeping on the ball now you've retired.

 

California Lemon Law applies within 18 months or 18K miles, whichever is first. If it is subject to repair 2 or more times and is a safety issue, and you have notified the manufacturer, they may need to replace the car or buy it back.

Your car has not yet been out of service for 30 cumulative days though.

Summarized & paraphrased from
Buying and Maintaining a Car | State of California - Department of Justice - Office of the Attorney General

See also http://www.dca.ca.gov/acp/pdf_files/englemn.pdf

 

Here's Nevada. Not sure if either would apply.
Nevada Lemon Laws - Lemon Law Attorneys | DMV.org

Here are some random lawyer opinions when your purchase crosses state lines.
Which state lemon law does my new car purchase - Q&A - Avvo

 

i don't understand manufacturers. they spend billions in r&d, make billions in profits, but faint at the thought of replacing a clearly defective car with a new one that might cost them 10 grande.

 

... or fixing it. Surely putting on a "left front speed sensor" on a car which has shown it faulty in the past wouldn't break the bank - and improve the impression of customers.

Customer service is one of the biggest aspects of whether buyers return for another car - or not.

When mine had MALFUNCTIONs all flick up on the screen, they never repeated itself for 4 months. But service, seeing it in the computer log, didn't hesitate to change the defective part.

 

Nothing brings em back like a good impression.

 

ECU means “electronic control unit,” that is, any of a car’s myriad computers.

The ECU reporting two of the diagnostic trouble codes (DTCs) you mentioned is the skid control ECU, part of the anti-lock brake system (ABS). The skid control ECU is part of the brake booster with master cylinder assembly (47050-47550), and if the ECU is defective, the whole assembly must be removed and replaced.

Possibly, since the the list price for the master cylinder assembly is $2,500 or so, though the actual cost to Toyota is no doubt much less. Remember that Toyota sells parts to their dealers, but then reimburses them for the cost (plus labor) if they are used for warranty claims; Toyota also gets the old parts back, if they want them, for rebuilding or failure analysis.

The situation is similar with the rear speed sensors: the sensor is part of the rear axle hub and bearing assembly (for the right side, 42450-76020, list price $330 or so) and not replaced separately in the field.

According to Toyota’s Repair Manual, DTC C1403 (Malfunction in Rear Speed Sensor RH Circuit) means the skid control ECU detected one (or more) of these conditions:

INF Code: 521 — At a vehicle speed of 10 km/h (6 mph) or more, output voltage from one of the speed sensors is less than that from the other sensors for 15 seconds or more.
INF Code: 522 — At a vehicle speed of 10 km/h (6 mph) or more, outputs from both speed sensors are 0 km/h (0 mph) for 15 seconds or more. (except when both rear speed sensors are 0 km/h (0 mph)).
INF Code: 527 — At a vehicle speed of 10 km/h (6 mph) or more, output from one of the speed sensors is 0 km/h (0 mph) for 1 second or more.​

DTC C1407 (Open or Short in Rear Speed Sensor RH Circuit) means the skid control ECU detected one (or more) of these conditions:

INF Code: 523 — An open in the speed sensor signal circuit continues for 0.5 seconds or more.
INF Code: 526 — The speed sensor power source voltage is low for 0.5 seconds or more.
INF Code: 528 — The speed sensor power source voltage is low for 0.2 seconds, and does not return to normal for 60 seconds or more.​

DTCs C164D, C1A50, and C1A45 all indicate that other ECUs received failure indications from the skid control ECU; when occurring together with C1403 and C1407, they’re unlikely to indicate separate problems.

The troubleshooting procedures for DTCs C1403 and C1407 can lead to replacement of the skid control sensor wire, harness, or connector; the rear axle hub and bearing assembly; or (for C1407 only) the brake booster with master cylinder assembly—but only if the technician is able to identify the defective part.

Unfortunately in your case, if the DTCs don’t return after a road test, and the speed sensors work when checked with the diagnostic system, the procedures say to “Use Simulation Method To Check,” which means trying to reproduce conditions (such as vibration, heat, moisture, or high electrical load) that might cause the problem to return. As Toyota writes:

The most difficult case in troubleshooting is when no problem symptoms occur. In such a case, a thorough problem analysis must be carried out. A simulation of the same or similar conditions and environment in which the problem occurred in the customer's vehicle should be carried out. No matter how much skill or experience a technician has, troubleshooting without confirming the problem symptoms will lead to important repairs being overlooked and mistakes or delays.​

Like all automakers, Toyota clearly wants to minimize their warranty costs by discouraging “shotgun troubleshooting”—replacing every part that might be causing a problem, rather than finding and replacing only the truly defective part—but considering that ABS is an important safety system, and the trouble has returned twice, it may be justified in this instance.

If I were troubleshooting this problem, I wouldn’t dismiss the possibility of an intermittent wiring fault, though—wiring and connectors are among the least reliable components in any electronic system, and even if the dealer checked the terminals, connectors, and exposed wiring carefully, they may not have examined the sensor wires along their entire length. This could require considerable disassembly, which carries the risk of causing other problems; if the needed equipment were handy, I’d disconnect the sensor wires and make insulation resistance (megohmmeter) and time-domain reflectometry (TDR) tests first.

 

Perhaps you need to bring this to the attention of priusteam. Sorry, I can't remember the exact handle but @Prodigyplace will.

 

I do think @Prius Team would be interested because marketing is no good if good service is not provided.

 

Thanks ol' buddy. Knew I could rely on you, but for some reason that option wouldn't offer up when I tried it earlier.

 

typing @prius, and a space, and a "t" does the trick. So far. Just figured that out myself.

 

@mjustice, I just came here to do some research and realized I'm having the exact same scenario with my 2016 Prius Four with ATP/PCP. It all started a week ago when I returned from an overseas trip and the car had sat unused a few months. Ditto to everything you wrote.

The problem comes and goes. Took it to the dealer yesterday and they were able to replicate all the warning lights, but they had no loaner car so I was pretty much forced to leave with no resolution, as I need a way to get to work. So I've been nervously driving the car since then.

Looks like I am in for the same frustrating journey as you.

 

2 weeks and no prius team response? shocking.

 

Have you tried charging the 12v battery up ?
All sorts of warning lights and such come on with the Gen 2 when the 12v is low, maybe it's the same with the Gen 4 ?
My Gen 4 gets used very little (<3K miles a year) and gets left unused for only a few days at a time, but even so the 12v does run down a bit. I use a Ctek (3.8A max) battery reconditioner every couple of months to bring it back up.