Specific Info/Advice for buying older Prius?

The list of potential problems is quite long; I hope you had a chance to take a thorough test-drive prior to buying that vehicle:

1. Electric steering gear fails, manifested by considerable vibration in the steering wheel
2. Starting problems due to engine ECU not allowing sufficient time for the engine to start before logging a diagnostic trouble code, or a marginal fuel pump that generates insufficient fuel line pressure, which requires fuel tank replacement. The throttle body and throttle body plate tend to accumulate black soot over time; cleaning this may help reduce driveability symptoms
3. Accelerator pedal assembly has dirty potentiometers, causing lack of engine response when you depress that pedal
4. Catalytic converter failure, either due to the HCAC valve sticking, or the catalytic converter itself failing. A very costly repair since this is a non-standard design
5. Inverter overheating problem, requiring inverter replacement
6. Need to upgrade hybrid vehicle ECU firmware which requires installing a new ECU (2001 model year only)
7. The Classic transaxle is a weak point, I suggest replacing transaxle fluid at 30K mile intervals as a preventive maintenance measure
8. Fuel gauge inaccuracy, I don't recommend that you allow the tank to get very low, or risk running out
9. I also suggest that you have your car's VIN checked by your local dealer to ensure that all applicable SSCs (Special Service Campaigns, aka recalls) have been performed, especially the resealing of the traction battery modules and maybe the crankshaft position sensor replacement

 

While everything that Patrick wrote is correct, I think it might leave too strong a negative impression on the new audience! Have an urge to soften the blow.

Let’s start with the SSCs. The two he mentioned may pertain to your VIN. While you are checking, find out if the steering, an ECU, and anything else has already been replaced on the car. Then you will know where you stand.

Changing transaxle fluid is good maintenance as he suggested. Changing engine oil and filter and air filter are things I would do early after any used car purchase. While the air filter is out, look underneath for soot around the throttle butterfly. It is not difficult to clean.

I completely agree that potentiometers in the accelerator and steering torque sensor were a dumb idea by Toyota. The ones in the accel are easily repaired. In the steering they are not, so we shall cross our fingers there…

Neither model Prius seems to appreciate engine oil overfill, so don’t do that. Both have ‘wacky’ fuel gauges, so do not drive them into blinking E until your experience (or sense of adventure) increases. Neither can abide the inverters overheating, but for most drivers this does not cause problems. We can tell you what to look at, after the car arrives.

Both Prius models enjoy overall very good reputations as low-maintenance vehicles. Let us know what you learn about the history of yours, and we may have some more ideas.

 

I drove an '01 until I got an '04. My experience was that it was a good little car that didn't ask for much and worked fine. I had a couple of the preventative recalls that Patrick Wong mentioned done, they didn't cost me anything.

At six years of age if it has the original 12-volt battery it's time to change it. No lead-acid battery lasts forever. If you do, consider getting one that's bigger than the stock 12-volt. You can run that sucker down just by leaving the dome light on overnight. I also replaced the wimpy stock domelight and trunk light with LED replacements, liked the results. Feel free to contact me if you have questions.

 

Doug Schaefer (tochatihu) in the past had a small business repairing the gas pedal potentiometers. He has since passed that on to Bob Wilson.

In general you should expect that all parts will be sourced from a Toyota dealer. Since you have the ability to buy wholesale, no problem. I've been getting a 25% discount from list from this dealer:
http://www.trademotion.com/partlocator/index.cfm?siteid=213747

MSRP on the steering gear is $1,359. A new accelerator pedal assembly is probably a few hundred $s. You've got the right idea regarding the 12V battery; Toyota issued a TSB and offered a higher capacity Panasonic battery (31 AH I think) for sale, to replace the original equipment GS battery rated at 28 AH.

Note that the 12V battery is absorbent glass mat construction and is vented. As you work on your own cars I am sure you can appreciate the safety issues associated with using a replacement battery that lacks those features and can make up your mind about whether the tradeoff is worth the lower price of a standard battery.

I strongly suggest that you either purchase the paper repair manuals or else subscribe to the following website and download the repair documentation for your model year: techinfo.toyota.com

Then you can learn about safety issues as well as the many unusual Prius components such as electric steering, the braking system, the hybrid transaxle, traction battery, how the many ECUs relate to each other, etc.

Also note that a generic OBD-II code reader cannot be relied upon to pick up the numerous DTCs that the various ECUs (engine, hybrid vehicle, traction battery, power steering, etc.) are capable of generating. So if your car has several problems it may be necessary to have a Toyota mechanic retrieve all DTCs using the special Toyota diagnostic laptop or handheld tester so that you have a full list to work from.

Good luck.

 

See the attached file that describes a related recall. Although only a few cars were subject to this particular recall, the Classic electric steering gear was a widespread problem and Toyota retroactively offered a 5 year warranty. That part failed on my 2001 when it was about one year old. Even after it was replaced, the steering wheel twitched slightly now and then, which caused me to be worried about a repeat failure...

There is a Haynes manual. Based on the comments from PriusChat members who own that manual, I would say it is not useful for an owner who actually expects to perform repairs.

Bentley will eventually publish a Prius repair manual. Based upon my prior experience owning their manuals for VW cars, this might be a better aftermarket source.

If you start by investing $10 in a one-day subscription to techinfo.toyota.com (which actually will run all weekend if you start on Friday) then you may find that you can download sufficient .pdf files so that you don't need to buy the paper manuals. Its up to you.