Mechanics

ECM PROBLEM

2001 Toyota Sienna

Engine Performance problem
2001 Toyota Sienna 6 cyl Front Wheel Drive Automatic 91000 miles

My 2001 Sienna initially died out. I took it to the dealer. the cleaned the throttle body and IAC valve. It ran better and they suggested changing the IAC valve if it happened again. Well it did die out again and I changed the IAC valve. It would not start. I put the OBDII scanner on to check for codes and no codes. previously there were NEVER any codes present. While the tester was hooked up I tried starting the van bt accident and it started up with the tool plugged in. I pulled the scan tool itself and left the cord on and the van continued to run with just the cord plugged in. Cord gets warm a little. Once I pull the cord it dies out. I am thinking the ECM is bad. my vin is 4T3ZF19CX1U400816. 2001 Sienna automatic V-6. this is a link to a site with the ECM I found with my correct vin and model # http://www.toyotapartszone.com/online/Page_Product/PartDetail.aspx?vinnum=4T3ZF19CX1U400816&VAID=1562&productiondate=200106&catalogCode=622410&sectionID=4&isBigPicture=False&componentsID=84-04&componentsIndex=13
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Szalkuskt
May 22, 2010.




Hi there,

Thank you for the donation,

If the ECU is suspected of being faulty you may have the option of testing the car with a test ECU, ask your EFI specialist if any company offers test units to run in the car, here in Aust we can get a good known ECU to test the car to determine if the problem is in the ECU, if not there is only a small charge for the use of the ECU, this may be an option open to you, this will save many $$$ if the problem is not an ECU fault and you go purchase one, check this out.

Mark (mhpautos)

Mhpautos
May 27, 2010.
Well I found an ecm on ebay for $79 usd. It is the same part number from the one I removed but it is the newer remanufactured one with -84 part # on the end. The very same one as on the website link I provided above. It was out of a salvaged car. I am waiting to receive it and install it. Do you know if the odometer reading will change? I am thinking that if I replace the ecm with this newer remanufactured one it will fix the problem. The van was running when I had the obdII cable plugged in and someone mentioned the ecm may not be grounding out things correctly.

Tiny
Szalkuskt
May 28, 2010.
The speedo reading will not change, the used ECU may well solve the problem, but you have to be prepared to keep it if it does not as I am sure that they will not take it back, that is why I use the test and return system here, but as it is quite cheap, this may well be an option open to you, and if it does not work you can always sell it on again, this is now getting to the point that it need to be inspected first hand as working blind like this has some draw backs, I am going to have a read up on your system this week ens and I will post any further thoughts soon.

Mark, (mhpautos)

Mhpautos
May 28, 2010.
Well, I have not put the ecm in yet. It is a newer remanufactured model of the correct part number for my sienna though, so I am guessing it is not made in 2001, it has since been changed at one time. I dunno. I hope you could figure out why my car would run with the OBDII cable hooked up and die when it is pulled. Where is the connection #8 I believe where someone said I should look? A schematic so I could identify pins on the ecu will help me.

Tiny
Szalkuskt
Jun 1, 2010.
Well I got the other ECM from ebay that I bought and I hooked it up and it did not work at all. This time with the 2nd ECM installed it now will not start. Before with original ECM, the van would start only with the OBDII cable connector plugged in. Now with the 2nd ECm, the van will not start. So, this leads me to believe that it is an ecm problem and I should take the original ECM and have it sent to be refurbished but am I still working in the blind? Is a ECM refurbisher legitimate?

Tiny
Szalkuskt
Jun 5, 2010.
Yes it is, that is what I spoke of in earlier posts, getting a known good test unit, some manufactures offer this service, I just don't know who in you part of the world does it, larger parts suppliers that deal with the trade may have information on this.

Mark.

Mhpautos
Jun 5, 2010.
What do you mean by a known good test unit? Use a re furbished one?

Tiny
Szalkuskt
Jun 6, 2010.
Yes, I would expect that the larger fuel injection specialist company's, (ask your mechanic about this) may do trial units, if it fixes your problem you purchase it, if not you pay a small fee to get the test unit re certified serviceable and you look further for this error. You will have to ask your mechanic if this practice is done in the USA, we do it in Aust.

Mark

Mhpautos
Jun 6, 2010.
Well my van is at the dealer and I drove it there with the obdII connection cable connected. I provided them with the original ECM unit(the one installed in the van). I also provided them with another ECM unit with the -84 part number and its the remanufactured unit. They can see that the van will start and run with the OBDII cable connected to the van. Also, what is involved with programming an ECM to a vehicle once you have a replacement one? I called an ECM refurbishing shop and they said even though I have a replacement ECM, it will still have to be reflashed to the vehicle. What can anyone tell me about how they do that?

Tiny
Szalkuskt
Jun 8, 2010.
Well, the dealer said it is a ground problem in the ecm and the 2001 ECM is a plug and play unit and does not require reflashing. I have to buy an ecm and put it in. I am having trouble finding an ecm
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Tiny
Szalkuskt
Jun 9, 2010.

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