2001 doesn't like being parked on slopes overnight?

If the check engine light came on, then a diagnostic trouble code will have been logged. I suggest you visit your dealer as soon as possible so that the code can be read.

My guess is that your car was parked so that the engine is uphill compared to the fuel tank, and that your fuel pump is marginal so that fuel pressure is not building up. Therefore, the gasoline engine is not starting. Since you said that "shortly thereafter, the ICE cuts out", it probably never started at all, but was just being spun by MG1. When Classic is started from a cold start and left in Park, the gasoline engine will usually run several minutes before the first auto stop.

I do not suggest that you drain the 12V battery, that will not be helpful.

 

Some codes can only be cleared by entering the correct drive sequence. Some codes require the dealer scantool to clear.

I would *never* suggest draining a battery to clear codes. You're much better off disconnecting the battery, waiting 10 mins or so, then reconnecting. The Prius 12 vdc battery isn't very forgiving of being deeply discharged

 

Probably not related but have you had the throttle plate cleaned?

Would the slope area be where water and humidity might be a little higher and possibly a little cooler than the other areas? Cool and high humidity are associated with the throttle plate sticking.

Bob Wilson

 

Well, there should be no gas smell in any event no matter what you do, unless you have a fuel line leak or a problem with the evaporative emissions control equipment attached to the top of the fuel tank.

I'd again encourage you to visit a competent dealer's service dept if one exists in your area. They should only charge you for one hour of diagnostic time to read the DTC.

If you disconnect the 12V battery, that will erase whatever codes currently exist.

 

This is an interesting one, unfortunately I do not have much to add. Could it be that the fuel tank was nearly empty, or the engine oil is substantially overfilled?

As a 2001 Prius 'off-roader' I have parked the car at some quite extreme angles, but never had this problem.

Please tell us what you find out, and if the throttle plate was stuck with soot (as Bob W proposed).

 

Re: Update...ugh...

TSB EG011-03 is the relevant TSB, which I attached to this msg.

The 12V auxiliary battery should cost ~$160. The circuit opening (aka fuel pump) relay should cost ~$75 and lives in the relay/fuse box near the inverter. If you have the car back at home you can easily replace both parts yourself.

The TSB suggests replacing the engine ECU, not because the old one failed, but because the current revision ECU has different firmware that allows more time for the engine to start before giving up and logging a DTC. If your car is at home, you can look at the engine ECU and compare its part number to 89661–47054 which is the current part number. The engine ECU is located behind the glovebox.

If your car has been working OK in prior winters and only this winter is having trouble, you might also consider doing a tuneup by changing the iridium spark plugs and cleaning out the throttle body and throttle plate. Change the air filter if dirty. That might be enough to eliminate the driveability issues you are now noticing so that there's no need for the new engine ECU.

I am surprised that the dealer didn't want to replace your fuel tank. That has been a frequent response to the problem you face.

 

I suggest you call and ask what DTC were logged, and what TSB they are relying upon in making their diagnosis. If the TSB is different than the one I provided, I'll see if I can find it in my files. If not, you might decide it is worthwhile obtaining it from the subscription techinfo.toyota.com website.

You could buy the battery & relay at the dealer and install the parts in the dealer's parking lot. This avoids the return tow charge.

If you can find the relay box that I am talking about, the latch is at the leading edge. Depress the latch so that the box opens. The inside of the box has a map that provides the names of all relays and fuses within. Use a small flat-blade screwdriver to gently pry up the old relay (which has four connector lugs) and replace with the new relay.

To access the battery, you have to remove three plastic pins that hold the trim piece in the trunk that hides the battery. Then you will need to remove the hold down bracket and the battery cable connectors.

It would be best to buy the original battery size if you can. Another TSB offers a larger-capacity Panasonic battery in place of the original GS battery, but this requires installing a new battery bracket and new battery terminals, not easy to do without proper facilities.

 

Re: Update...ugh...

 

Re: Update...ugh...

DTC P3101 is logged by the hybrid vehicle ECU and indicates an engine system malfunction. Frequently that is accompanied by the engine ECU logging DTC P3190 or P3191 (poor engine power, or engine does not start.)

If your 12V battery is original, I recommend that you replace it now just because it is 7 years old. The 13.79V voltage measurement that you provided is incorrect, if the car is IG-OFF. That measurement more likely is when the car is READY. Try measuring the battery voltage when the car is IG-OFF, after the car has been sitting overnight.

Look at the throttle body interior and throttle plate. Those items need to be clean, if you see black gunk, then clean it off.

I suggest that you follow the troubleshooting advice in the TSB that I posted earlier in this string:

First ensure that the engine is in proper tune: only use the correct iridium spark plugs, replace if needed. Check the engine air filter and replace if dirty. Check engine oil level, which should not exceed the top dimple on the dipstick. Engine oil viscosity should be 5W-30.

Remove and check the circuit opening relay by applying 12VDC across the relay coil terminals and measuring resistance across the switched terminals using a digital multimeter. If resistance is more than 0.5 ohm, replace the relay (as excessive resistance will reduce the voltage provided to the fuel pump.)

If you still have trouble, check fuel line pressure which should be 43 psi. If much lower, then you'll have to replace the fuel tank because the fuel pump is hidden inside.

Check the part number of the engine ECU which is located behind the glove box area. If it is downlevel and if the previously described service activities did not reveal any problems, then replace the ECU with a salvage unit, should cost ~$200 or so. Good luck.