2002 Prius Red Triangle and intermittent stalling

If you want to force the engine to run, you need to depress the MAX AC button and if necessary turn the temperature dial to the lowest setting possible - 65 degrees, IIRC. Or you could invoke inspection mode, do a search if you want to put the car into that mode.

Besides the red triangle, are there any other warning lights on the instrument panel, or warning icons on the MFD? If so, then hopefully a DTC has been logged and if you can retrieve that then you'll have a clue as to the problem.

It is normal to be able to rotate the throttle plate via the spring-loaded shaft when the car is IG-OFF. It is also normal not to be able to do so when the car is READY, as the throttle motor is powered up and is adjusting the throttle where the engine ECU thinks is appropriate.

It certainly wouldn't hurt to replace the iridium spark plugs and engine air filter, and clean the throttle plate and MAF sensor. However there's no assurance that will help the problem since you don't know what the problem is.

Once you get the engine running properly, you also should replace the engine and inverter coolants as that maintenance is way past-due and it is likely that some clogging of the systems has already occurred.

 

We need the codes to really understand so if you'll look at the thread "03' Classic Prius and scanguageII", we are working on how to read out codes using a scangauge. One important thing is to make a pig-tail to limit the scangauge to just the signals the NHW11 handles.

Let me suggest stopping by Lowes or Home Depot and getting:

• RJ-45 female connector - typically punch down, they come with a little tool to push the wires onto the connector
• short ethernet patch cord - cheap

What you'll do is cut the ethernet patch cord in half and punch one end down to the female so it passes only four signals:

	Column 1	Column 2
0	pin	signal
1	1	ground
2	6	K-line
3	7	L-line
4	8	12 V power

Thanks to vincent1449p for the sketch and w2co for his modification.

The scangauge by default will read out some codes. Thanks to vincent1449p, we also have the codes needed to define XGAUGEs to read out many addition NHW11 specific data values. Let's try and use your scangauge first to read out the codes. NOTE: if you use the scangauge without the adapter, it can 'spike' the ABS controller and induce false codes.

If we run into a problem with the scangauge, I can rent a Graham miniscanner. But let's try and use the tool you have before bringing in 'the big dog.' <grins>

BTW, could you read out the 12 V battery voltage with the car off? Your running voltage, 13.8 V, means the inverter 12V DC-DC converter is working. But with the car powered off, the 12 V battery needs to read a little above 12 volts.

Bob Wilson

 

Either NGK or Denso is fine, but please note the correct spark plug model numbers as listed in the owner's manual and purchase one or the other.

Be cautious about purchasing other "compatible" iridium spark plug models, even from NGK or Denso. "Compatible" means the plug will fit in the threaded hole and is the correct heat range. However the useful service life of the spark plug may be much less.

This thread cites a potentially inexpensive way to purchase the correct Denso plugs, through a GM dealer:
http://priuschat.com/forums/gen-ii-...shooting/83507-cheaper-gen-ii-sparkplugs.html

 

Everything sounds great but I would caution on engine cleaning in one area.

Under the windshield washer pan is a junction box that connects MG2 and the inverter. The cover has a small vent tube that is facing down. My concern is if the box is warm or hot from running and it is sprayed so it cools, it might suck in a little moisture and lead to the P3009 code, leak to ground:


If you can avoid spraying in that area and/or do the wash without having the car warmed up, it is probably going to be safe. It is in an obscure area so you might stuff some newspaper or other material in to block spray in that area. As for the rest of the engine compartment, 'fire away.'

One other cautionary area is the hydrocarbon converter between the manifold and muffler. Obviously this is a very hot area so you might put the car up on jacks and let it cool off overnight. Get some high-temperature grease (lithium?) and check the linkages the next morning. Look for corrosion and lubricate the linkages.

GOOD LUCK!

Bob Wilson

 

Glad to hear that your tune-up work helped. Are you saying that P0420 has gone away now?

Regarding this Seafoam, I would be cautious about use of such products unless the car has a problem that would be addressed by that chemical. At the moment it doesn't sound like your car has a problem with a clogged fuel injector.

Regarding the 12V battery, that voltage reading is on the low side of acceptable (12.9V is what a new fully-charged AGM battery will read.) I suggest you put it on a battery charger overnight. Then let the battery rest for several hours subsequent to being charged. If the battery voltage still measures 12.3V, you might think about replacing the battery before the cold winter season. <I don't know about your family situation, but my wife expects high reliability in all of our household vehicles, hence I like to replace the 12V battery before it fails.>

 

I am having these same symptoms.

I dropped my car off at the dealer, and will see what they say.

Have you had any other issues after the maintenance you did?

Thanks

 

We have a 2001 and had similar issues. Ended up having to replace the Invertor water pump.

 

I'm having similar problems- shouldn't the invertor pump be running when you turn the key over one notch and the instrument panel lights up? Mine isn't, and I thought it used to. 2001 here with a remanufactured hybrid battery installed just a couple of months ago- won't start today. Shutters like it's going to blow up.