2002 power steering problem, I'm 300 miles from home. HELP!

You'll have to decide whether a safety issue exists or not.

If you can safely maintain control of the car, then no problem. If the vibration that you described below prevents you from safely steering the car then you should stop driving it.

Yes. You might try rotating the steering wheel from lock to lock a few times, maybe that would temporarily help the torque sensors.

 

Toyota just issued a recall on the steering system of the classic.

Do a search on Prius steering recall for info.

 

Toyota recall info below, sorry about your troubles.

Torrance, Calif., June 1, 2011 – Toyota Motor Sales, USA, Inc. (TMS), today announced that it will conduct a voluntary safety recall involving approximately 52,000 2001 through 2003 Prius vehicles sold in the U.S. to replace the electric power steering pinion shaft attachment nuts. This announcement is for U.S. vehicles included in Toyota Motor Corporation’s global recall of 106,000 vehicles.

If the steering wheel is repeatedly and strongly turned to the full-lock position, there is a possibility the nuts securing the pinion shaft in the steering gear box assembly may become loose. If the vehicle is continuously operated in this condition, over time, the customer will gradually notice significant increased steering effort when making a left turn.

Toyota dealers will install improved nuts that secure the pinion shaft at no charge to the vehicle owner. The repair will take approximately 4 hours depending upon the dealer’s work schedule.

Owner notification letters by first class mail will begin in early July, 2011.

The separate recall announced by TMS involves 34 Venza AWD and 16 Sienna AWD vehicles to replace an insufficiently heat treated front right-hand driveshaft. All of these vehicles are recently produced 2011 model year. Only 38 are expected to have an insufficiently heat-treated driveshaft.

Due to insufficient heat treatment, there is a possibility that the front right-hand driveshaft may break. If this occurs, engine power will not be transmitted to the wheels and the vehicle will coast to a stop.

No other Toyota or Lexus vehicles are involved in these recalls and the driveshaft recall only involves vehicles in the U.S. and Canada.

Owner notification letters by first class mail will begin in mid June, 2011.

Detailed information and answers to questions are available to customers at www(dot)toyota(dot)com/recall]Toyota Recall Information ? 2009-2011 Toyota Recall List[/url] and the Toyota Customer Experience Center at 1-800-331-4331.

####

Contact(s):MEDIA CONTACTS:
Lexus Vehicle Safety and Quality Communications
Brian R. Lyons (310) 468-2552
John Hanson (310) 468-4718

Toyota Motor Sales, USA, Inc. Media Line (310) 468-5297


Tags:
safety/recall toyota prius venza sienna

 

Isn't the Prius drive-by-wire? If so, how can the power steering go out?

 

The Prius steering system has an electric motor that provides steering assistance. The steering gear is a traditional rack & pinion design, hence the steering will operate if the car is IG-OFF.

 

Let's define "drive by wire". This means that there is no mechanical link between the input device that the driver touches, and the item which is being controlled.

The accelerator pedal is drive by wire because the accelerator pedal has no mechanical linkage to the throttle plate. The pedal assembly contains a couple of sensors which detect pedal position. The sensors are connected to the engine ECU. The hybrid vehicle ECU and engine ECU determine how much power should be developed by the engine, and the engine ECU provides a signal to the throttle motor to open the throttle an appropriate amount.

The brake pedal is partly drive by wire because under light to moderate braking, the pedal motion is monitored by the skid control ECU and hybrid vehicle ECU and the HV ECU determines how much regen braking should be developed by MG2. The skid control ECU controls the brake actuator which provides hydraulic force to the brake wheel cylinders as required for friction braking to supplement regen braking.

Under an emergency stop situation where friction braking is employed then a direct hydraulic fluid path exists between the brake master cylinder and the brake wheel cylinders.

The steering wheel has a direct mechanical connection to the rack and pinion steering gear which controls front wheel steering. Power assist is provided by an electric motor based upon input from torque sensors (within the Classic steering gear or on the 2G steering shaft). Hence this system is not drive by wire.

 

Highway driving in this mode is not difficult at all. Parallel parking and other low-speed maneuvers will give your arms a workout. If you haven't the arm strength, it should certainly be considered a safety issue at low speeds.

The new quoted recall certainly adds some context for those of us who previously recommended reducing the electric-assist steering systems by turning the steering lock to lock. And not in a good way.

 

Although a lot of lock-to-lock action might loosen the pinion nut, fortunately there is no need at all to turn lock-to-lock just to improve the sensor signals. They are torque sensors, not position sensors, and you can put them through their full range of travel simply by putting enough force on the steering wheel in both directions while the wheels on the ground stay pretty much stationary. Easier on the tires too.

You can do this just by parking on hard pavement with the key in, steering unlocked, but ignition off, and turning the wheel left and right as hard as you can without really moving the front wheels. Ignition has to be off for this or the car will assist you and you won't be putting full force on the torque sensors.

If you want to be sure you're applying enough force to work the sensors over their full range, just drop the glove box for access to the EMPS ECU, unplug the motor connection so it can't assist you, hang a voltmeter on the sensor plug, and then do the same exercise with the ignition on, making sure you put enough force back and forth on the steering wheel to repeatedly hit 0.5 and 4.5 volts. That's the full sensor range. (Once you have the feel for how much force that is, you won't have to bother with the voltmeter next time.)

All done without really pivoting the front wheels at all, much less lock-to-lock.

-Chap

 

The power steering on my 2001 Prius quit months ago. I am driving it just like I drove cars in the days before power steering. On the highway I hardlly knotice the difference. Parking and low speed steering are more difficult, but not much different that the 1942 Chevrolet that I used to drive.