can i call what i'm experiencing an SUA, and other issues

On your Issue #1: There is some slack in the parking pawl. When the ICE kicks in, there is going to be some torque going through the Power Split Device gearset as MG1 is being spun up to charge the battery, which is why there is a slight rocking due to the slack in the pawl. Solution is simple-- USE YOUR PARKING BRAKE! Whenever I put my '07 Prius in Park, I always engage the parking brake. Never had a problem with rocking since. There's a reason why it's called "the parking brake", you know.

If you engaged your parking brake and the car still rocks when ICE kicks in during Park, you need to get your parking brake adjusted.

On issue #2: At least it is not a critical safety issue. But I can understand why you would be annoyed-- I'd be pissed too if my steering wheel is crooked. Maybe contact Toyota Customer Care and file a complaint? Maybe you can get better service now that they are trying to improve their PR image.

On issue #3: That particular braking behavior has been discussed ad nauseum on these boards. It is the HSD computer temporarily cutting off regenerative braking to protect the electric motors (being used as generators during regen braking) from overload. When you feel that "lurch" and temporary loss of regen braking, the solution is to press on the pedal HARDER. This will cause the friction hydraulic brakes to actuate immediately. It is NOT "hackable." Not unless you know how to reprogram the HSD computer.

On issue #4: NO REGENERATION in Neutral AT ALL. In B-mode, you are using the engine's cylinders flailing to help slow down the car (like how one uses rev-matching in a manual-transmission car to help braking). B-mode does NOT improve regeneration at all.

If you are making it a habit to brake in N, you will find that your brake pads are going to get worn VERY quickly. In Neutral, braking is ALL hydraulic.

 

#1) It is a parking brake. Toyota has clearly stated that this is a parking brake, and is only useful in an emergency as a final method of braking just before you start dragging feet out of the door.

As for having the cable freeze, if you use it this won't happen. Likewise it is very difficult to drive off in a Prius with the parking brake set. The feel is a lot different than with any other car.

The play in the system in Park is the same as with any other automatic. They all have some play. It is inherent in the design of parking pawls. The difference is that the Prius starts and stops the engine at odd times. This is the nature of a hybrid drive system. If you drive a hybrid, you need to understand this and take appropriate action.

First, the movement is very small. If the small amount of movement creates a risk, you are parking too close to obstructions. Second, if you don't want to deal with it, power down or use the parking brake.

#2) Get the steering wheel aligned. It's not rocket science. Many Prius suffer alignment problems from being shipped overseas. This is why the dealer offers a free alignment on new cars. If your dealer is having trouble with this simple issue, you are using the wrong dealer.

#3) This has never been a real issue. The issue is new drivers unused to regenerative braking. Mostly it is a function of feel and getting used to how your car drives. It was worse in the Gen III, which is why a recall was made. The recall improves the feel of the braking system, but does not change the safety or efficacy of the system.

The traction control on the Gen II is more touchy. If you don't have good tires, get some. That will help a lot.

#4) Don't use B mode unless you drive in the mountains. There are very few situations where it is helpful unless you descend very steep hills.

Tom

 

To the OP:

Your reasoning is backwards regarding the parking brake, as those who live in snowy climates can attest: you should use the parking brake often, as it will keep corrosion from building up in the moving parts.

If you never use it, and then suddenly decide to use it one day, it very well could freeze up, due to the disuse.

 

The poll is biased because there is no selection for none of the issues.
The result will only show 100% that responded with problem.

 

The question about tires was in response to the "brake dropout" issue. The braking transition occurs when one of the front tires loses grip, which forces the braking system to transition to ABS friction brakes. Goodyear Integrity tires are very low friction tires, which means you will experience this a lot more often than someone with good tires.

VSC is an entirely different issue, although it is still related to tires. VSC kicks in when the car fails to go in the direction that the driver steers. In other words, when the car skids, VSC modulates the power and selectively applies brakes to try and bring the car back under control. There is no good reason to ever turn off VSC for a passenger car.

Tom

 

I doubt it. My father-in-law said the brake issue in his 2010 was a 'sudden sinking' of the pedal with no loss of braking power. The Gen II "braking on bad road or loose 'stuff'" is a BRIEF loss of braking with no change in brake feel. I think it only happens when you are in the transition from regen braking to friction braking. Can happen at the 7/8 MPH point or at higher speeds if you are braking lightly.

 

Dude, you are in New Orleans. Nothing ever freezes down there.

I am FAR north of you in New York. Never had my parking brake frozen.

The equipment is there, available for you to prevent the rocking. If you don't want to use it, then don't complain.

The Prius braking is a predictable behaviour that one can learn to compensate for. Every car has their own unique characteristics, and if this is not something you can tolerate, maybe you should sell your Prius and get a different car.

Nope. Traction control is handled by the HSD computer. No way to turn it off unless you hack the HSD computer.

No damage coasting in N. And the HSD computer will switch to N rather than P if you press P while the car is in motion above a couple miles per hour (the parking pawl will not engage).

 

You do not have SUA. That much is obvious.

But looking at standard 114 (49 CFR 571.114), it looks like a vehicle in park should not creep more than 150mm (S6.2.2.h and S6.2.3.h). That is 6 inches. Your vehicle appears to be within the standard.

 

1) Of course, if the parking brake freezes in the "depressed" position, it will cause the brakes to drag. But if you use the parking brake regularly, as already stated, then the components should not freeze up.

I lived in New England for many years. I live in Northern Kentucky now, and we get snow in the winter. The only time I ever had parking brake issues was decades ago, on used cars that I bought. Once the parking brakes were "fixed" on these used cars, regular use always kept them from "freezing" again.

2) I believe that the G2 Prius uses a cable.

3) The G2 uses the actual rear drum brakes for the parking brakes. Usually it's only the cars that have 4 wheel disks that utilize auxilliary rear pads for the parking brake.

4) I've never had to lubricate a parking brake cable for many decades. Not to beat a dead horse here :deadhorse:, but it seems that the cables nowadays can be kept from freezing with only regular use and no additional lubrication.

5) Drum-based rear brakes (like the G2 Prius has) will have some sort of "self-adjuster" in them. If the adjuster is over-adjusted, it can cause the rear brakes to drag. But this is easily rectified.

6) I don't know "how many times" you can drive with the parking brake on without it causing significant damage. I've done it on other cars on a couple of occasions with no lasting effects. Of course, it's usually only a few hundred feet before I feel that something is wrong.

If you try to drive the Prius with the parking brake depressed there will be a flashing warning on the dashboard that is very hard to miss. If you depress the parking brake pedal properly, it will in fact be very difficult to make the car move. Once you get in the habit of using the parking brake, try to "re-educate" your wife to step on the brake hard enough. Then when she tries to drive the car, even should she miss the flashing warning, she should immediately feel the difference.

Maybe you can also "gently" suggest to her that she actually look at the dashboard occassionally

7) If the parking brake doesn't hold well enough, try backing up the car at a good rate of speed, and then stepping firmly on the brake pedal. Repeat this a few times. It should cause the automatic adjuster for the rear brake pads to take up any slack in the rear pads to compensate for wear. If this doesn't work it may be because brake dust needs to be cleaned out of the rear drums.

8) Some people really rebel against using parking brakes on cars with "automatic" transmissions. But even with automatics, it's not a good idea to have the transmission rest on the parking pawl. So best practice is to use the parking brake even for automatic transmissions.

For those of us who used to drive manual transmissions (or who still do), using the parking brake is second nature. But the Prius' HSD is neither an automatic nor manual transmission, but a third type of transmission, if you will. There is no clutch. There are no different output "gears", but rather different power inputs that work with each other to propel the vehicle at the desired velocity and acceleration. So it helps to NOT think that "the car should not move at all in park".

If it were a manual transmission, you would have to have it in neutral (or in gear with the clutch depressed), and the foot or parking brakes set, in order not to roll or move. So keep in mind that "it's not an automatic (in the historical sense of the word), nor is it a manual, but rather something else". This will free your mind to learn how to handle a "new" type of drive system.

Best wishes,

 

Hello Nawlinsprius:

In response to your question about using neutral: for normal driving there are some occasions where neutral is not a good thing to use, as it might cause MG2 to overspin at higher highway speeds (from what I remember). Probably someone of the more knowledgeable members here will explain it to you. Or use can use the Search feature.

In the event of a true SUA, I think that the consensus is to first stomp "hard and fast" on the brakes. This engages the Braking Assist feature, which can almost put you through the windshield if you are not wearing your seatbelt. Next would be to hold the transmission in neutral for a few seconds (a brief tap while under power usually will not do it). Least desirable would be to power off (holding the button for a few seconds), which should still be safe enough to not cause any catastrophic failures to the automobile.

Best wishes,

 

This is just a guess, but perhaps the parking pawl now has more play due to wear. Wear that was quite possibly caused by your excessive reliance on "park" to hold the car because of your aversion to using the park brake.

Some members here even use a bit of extra caution to minimize the strain on the parking pawl mechanism. This involves shifting to N and applying the park brake first, then releasing the normal foot brake (if applied) and allowing whatever movement ensues to take up any slack in the park brake (and to ensure that the park brake will hold against the grade unaided) and only then to hit park (or turn off the car as the case may be). Ok it might sound a bit over cautious but this is what myself and some others here often do.

BTW. Re the question about B mode operation. Some people use B mode to give a bit more of a traditional engine brake feel when driving in mountainous terrain. I sometimes use B mode to actually reduce the amount of regeneration (due to the extra mechanical losses of turning the engine) when I have a very large decent that I know will give more than enough regen to charge the battery to the full 8 green bars. This just means it takes longer to reach the full state of charge which reduces the overall amount of friction braking used.

 

A minor correction: The self adjusting rear brakes on the Gen II Prius are not the normal adjust-when-backing type. Prius drum brakes adjust every time you use them. It's a very clever system that causes the adjuster to turn if there is excessive play in the system. It is not necessary or effective to back and brake to force adjustment.

Tom

 

Hey good to hear.

Just one other point about the park brake possibly sticking on. I think somewhere in the past you must have got the wrong idea about when this will and when this wont be a problem. The situation where the park brake can cause a sticking problem (on some cars) is when the car is left to sit for weeks on end with the park brake applied. Many guides to "mothballing" for example do tell you to avoid using the park brake if possible and to consider choking the wheels instead. Personally I've had occasions with older cars when I've left them parked for a month or more where the park brake did bind on from corrosion. They always did free themselves when I eventually drove them, but you could feel the drag and then hear a clunk as they released.

Anyway, this is not the case for normal use of the park brake, such as when you're on the ferry etc. As others here have already said, frequent use of the park brake will actually make it less likely to bind on.