Engine light is on - 2002 Prius

There have been many reports of similar things in the Classics
['01 - '03] as we're heading into this winter. Let me see if I've
got all the potential causes in mind here:
__ throttle body crapped up underneath
__ wrong oil or oil overfill
__ needs ECU upgrade
__ fuel pump and/or control relays
Unless the fuel pump or related really is bad, it's a case of the
ECU being a little too sensitive to how long the engine takes to get
running, and the engine being just a little too sluggish. That's
why it's a sporadic condition that's worse when everything's cold.
.
Search the forums and/or google for "P3191" and "prius" to find many
more accounts of this. Bottom line is that it's likely you can still
drive the car, with minor annoyances here and there, but you should
get it looked at for the common causes as soon as is reasonable.
.
_H*

 

<div class='quotetop'>QUOTE(prosec34 @ Dec 4 2006, 08:57 AM) [snapback]357316[/snapback]</div>

Just a little more information for you (adding to Hobbit's info).

1 - The throttle body get fouled and it's been assumed that it is due to overfilling the oil. There may be other long term causes as well.

2 - Cleaning the throttle body is not a big deal, get it done or do it yourself (the instructions can be found by a search).

3 - The reason Hobbit mentioned the P3191 number is that it is the TSB code for a free replacement of the ECU by your friendly Toyota dealer to make it less sensitive to slow starts. Get it done. They are likely to say that other work (not free) is also necessary, do the ECU first (and throttle body cleaning) and see if the problem goes away.

How many miles are on your Prius? You may want to consider changing the ATF fluid (in the HSD) if it hasn't been done (do it every 30,000 miles) and the spark plugs (also related to a possible starting hiccup).

JeffD

 

That makes sense... it takes 3 restarts to clear the CEL if the condition is no longer present (and from the description from Hobbit it's an intermittent problem that probably isn't currently present).

 

<div class='quotetop'>QUOTE(prosec34 @ Dec 4 2006, 10:40 AM) [snapback]357365[/snapback]</div>

At 35,000 you shouldn't need spark plugs.

You should put in new ATF (Type T). Bob Wilson has been collecting data that shows a 30,000 mile interval is about right for the classic Prius (2001-2003). My data on a 2004 Prius suggests a 60,000 mile interval for ATF (type WS) is about right. Of course this has nothing to do with your current intermittent problem, but is important for the long term health of your Prius.

JeffD

 

I have a 2002 Prius with 35,000 miles. I never have any problems with it until the temps start dropping. If it is below 30 degrees at times it will turn the check engine light on with the triangle of death on the first start of the day. I got tired of making an appointment at my Toyota dealership and by the time I was able to get it in to be checked out the light was not on any more and they were charging me a $70 diagnostic fee. I purchased my own code reader on-line for around $50. Now when the check engine light comes on I just clear out the code myself. I only use Amsoil oil and a factory TRD oil filter and I only use Shell gas,regular grade only, as they are listed as a top tier gas station. I have been considering having the ATF fluid changed. What is everyones thoughts on either using the factory ATF fluid of Amsoil ATF Fluid? Thanks!!!!

 

Chaining the transaxle oil is an excellent idea. However, my testing with Amsoil ATF showed excessive copper in the subsequent tests. There are reports that Amsoil ATF is hostile to 'yellow' metal like the bushings in our transaxles.

There are two schools of thought on using the OEM Type T-IV or newer Type WS. I'm pretty happy with Type WS and frequent changes. But I also respect those who decide to stay with Type T-IV. But please avoid Amsoil ATF unless you are prepared to test the oil, frequently.

Bob Wilson

 

I'm interested to know what DTC is logged by your car. If P3191 or P3101, then I suggest that you have the engine ECU replaced under TSB EG011-03. That is covered under the Federal 8 yr/80K mile emissions warranty.

I hope you are using 5W-30 viscosity engine oil. If you instead are using a heavier viscosity oil, that might be the reason for your engine no-start problem.

Regarding the transaxle fluid change, I suggest using Toyota ATF T-IV since that is the correct fluid for Classic vehicles, and Classic transaxles seem to fail at a non-trivial rate based upon complaints posted on this and other Prius forums.

 

I'm sorry I dont know how to start my own post to ask a question I cant seem to find the answer to any where. I'm a new prius owner and by the looks of what ive read on these forums I messed up pretty good by purchasing a 2002. I'm also new to this forum so please forgive me if i sound ignorant because I am as far as this subject goes. I really want to learn though. So here it goes. When I first start my car every day for the first time it takes about 3 tries maybe more for it to actually turn on. There is power but no engine comes on. And no significant sounds. Most of the time there is a check engine light on but after driving the car around it isent hard to start any more and the the light turns off. If I drive a for a while, I'm a delivery driver for food on an app, sometimes the ps light comes on and it is hard to turn the steering wheel. Today I was driving and the check engine light was not on there were no lights on and all of a sudden I couldnt accelerate. There were no noises nothing happend just couldnt accelerate. I put my hazards on turned off the car and it started right up and the problem was gone. Which also happens with the ps problem. If i turn the car off and turn it back on it is fine again. I read that you can get this cable to hook up to the orb reader and then to your laptop and there is a software some where on this forum that you can get for free to get the codes. If any one know what the cable is called and the link to where I can get the software I'll order the cable and can then go from there. I just cant find that post again. Oh yeah and the steering wheel some times starts shaking I read that is the power steering module. Any advice would be greatly appreciated and if any one can tell me how to start my own thread that would be great too. Thank you so much.