The Toyota Prius 1st generation (2001-2003)

The Toyota Prius 1st generation (2001-2003)

This was the second hybrid in the US market. When we saw it at the 2000 auto show, it was obvious that Toyota was rushing to get it out: the show car had the steering wheel on the right side and headlight and grill that had been broken and put back together with a glue gun. This car is very roomy, has adequate power, gets great mileage, and has brilliantly simple transmission that is only made possible on a hybrid car.

Unfortunately, we are starting to see some with wear and tear mechanical failures, but most first generation Priuses will make it to 100,000 miles before anything breaks, which is a whole lot better than whole lot of other cars.

What can go wrong:

There was a recall on the battery bus bar. Toyota did a very good job of getting the word out, and I’ve never come across a first generation Prius that has not had the recall done.

Some of the first generation Priuses had a recall on the EPS rack (electronic power steering rack). There was also a campaign on the EPS control unit. Most of these racks have already been done by dealers, but we’ve done two here that we not covered. You do need a factory scanner to do this job (or even to do an alignment) because there is a zero point adjustment that must be done after steering repair or adjustment.

We have now repaired/replaced 3 out-of-warranty HV transaxles. This is the part with the two motor / generators, MG1 & MG2. This is one of those things that works the hybrid naysayers into a frenzy. “See! I told you they were gonna break and be expensive to repair!”, they say. There is no denying that it’s expensive, but then again, anyone who owns a Subaru with a 2.5 DOHC motor knows that sometimes really expensive stuff breaks, and the Subaru is a conventional car, that gets less than 1/2 the MPG and cost the same as the Prius when it was new, and is worth far less than the Prius now that they’ve deprecated. So there!

Sometimes the gas motor does not start when cold once the car gets to 100,000 miles or so. This causes the Master Warning Indicator (the exclamation point) to come on. There is an updated ECM that may correct this problem on some cars.

Sometimes the electronic throttle body gets stuck and the MWI will come on. It usually will start to work again after a key cycle (turn off, then turn on). I’ve been told by a very good Toyota tech that cleaning the throttle body will not help (based on his own experience with a whole lot of Priuses). Hobbit (of Prius hacking and lighting systems internet fame) is convinced cleaning will cure the problem. We’ve seen one first generation Prius with this problem so far, and we replaced the throttle body.

The gas pedal position sensors reportedly go bad often. We’ve actually never seen a first generation Prius with this problem. Were they all fixed under warranty? I don’t know.