Where is the ECU Located in a 2001?

There are several ECUs in any Prius.

The cabin air filter is the one located behind the glove box. The engine air filter can be found in the engine compartment in the large black rectangular container near the front of that compartment.

I suspect that you are referring to the engine ECU since you are talking about starting problems. That can be found after you lower the glove box down. Look into the opening, on the right hand side. You will see the engine ECU with multiple wire connectors attached to it.

As to where to buy one, if you want to buy a new one and pay ~$1,000, you can order from one of the Toyota dealers that sell over the web; for example I buy from Champion Toyota in Houston.

If you want to buy a salvage unit, do a Google search for places that sell salvage Prius parts; of course you will need the correct part number.

However, given your post above, I am wondering whether you have the background to successfully remove and replace the ECU without causing damage to the car (or yourself).

 

When I sold my 2001 I also sold my repair manuals. If you would like to download the official Toyota repair docs, pls subscribe to techinfo.toyota.com

To step back for a moment, I believe that you previously posted about engine start problems. The relevant DTC should be P3191/P3101. I am assuming that you have verified that the iridium spark plugs are in good condition, the spark igniters look OK (no cracks, burn marks, corrosion), the engine air filter is reasonably clean, the throttle body and throttle plate are clean, engine oil viscosity is 5W-30 and not overfilled, and you have sufficient gasoline in the fuel tank.

If you have addressed all of the above and still have engine start problems, then it is time to replace the engine ECU if it is downlevel. You'll probably have to remove the current ECU to verify the part number.

The latest revision is 89661-47054, and that is the one that you need to install. When you remove the current ECU, verify that the part number is 89661-470xy (where x is 3 or 5, and y is 0 or 1), so that you can confirm that you have removed the engine ECU and not some other ECU.

In brief, the removal procedure would include the following:

1. Make the car IG-OFF
2. Disconnect the negative terminal of the 12V battery so that all ECUs can power down
3. Gain access to the engine ECU by removing the glove box
4. Carefully remove all engine ECU wiring harness connectors
5. Remove hardware securing engine ECU to the dashboard frame
6. Examine ECU part number and confirm this is the one that you need to replace
7. Assuming that the engine ECU is downlevel (part number other than 89661-47054), order an ECU with part number 89661-47054
8. Install new ECU, connect wiring harness connectors, attach negative 12V battery terminal connector, test-drive car in cold weather & see if you note any improvement.

I'm interested to know what ECU part number is currently installed, after you have determined this. Good luck.

 

make sure not to remove any other ECU, the HV ECU is also located in the same vicinity, and I believe it needs to be authenticiated with the transponder ECU and your vin number.

 

On Classic, the hybrid vehicle ECU is actually located under the passenger-side (RH) carpeting below the dashboard.

 

Thanks for the update; this part number shows that you currently have the second revision ECU installed; -47054 is the fifth revision. If this doesn't work, then you'll need to check fuel system pressure - but I think that is a relatively low probability issue.

 

The air filter you saw is the "Cabin Filter" and filters the air that enters the inside of the car. The service schedule calls for its replacemnt occasionally. The ECU is located under the floor of the passenger side of the car where the floor slants up to the firewall. The ECU is not hard to get to. Remove the plastic kick panel. Pull back the carpet and you will see a metal panel with about four screws. Remove the panel and you will see the ECU.

 

This was not an easy project to complete correctly; congratulations on your success!

I note that one msg mentions a price of $300 while the other says $500. Does the $500 figure include other parts besides the engine ECU?

 

How cool!!