2001 Toyota Sienna PO420 ECM replacement

Tiny
SVNOVA
  • MEMBER
  • 2001 TOYOTA SIENNA
  • 6 CYL
  • 2WD
  • AUTOMATIC
  • 148,000 MILES
Technician says need to replace ECM bases on Toyota Tech Bulletin. It is not under warranty anymore. First, is the Cat Converter really bad and needs to be fixed? Second, why would Toyota put a defective ECM and not replace it?

If it is just a false alarm because of defective ECM, can I just ignore it?
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Sunday, April 4th, 2010 AT 9:57 AM

6 Replies

Tiny
CARADIODOC
  • EXPERT
Hi svnova. You need to provide some more details. How does the catalytic converter play into the story? What are the symptoms?

Since 1996, the Engine Computer uses a second oxygen sensor after the catalytic converter to monitor its efficiency. It will memorize a diagnostic fault code and turn on the Check Engine light if it detects a problem.

Since the mid 1990s, most Engine Computers can be "reflashed" with new software. This is done periodically as updates for known issues become available. Chrysler, Toyota, and Hyundai are some of the few companies that allow independent repair shops to do this for you over their web sites at a fairly low cost.

The manufacturers do not "put a defective ECM and not replace it?" A technical bulletin or a service bulletin has nothing to do with warranties or recalls. They are simply notices documenting known issues that might take a long time to diagnose. The information is designed to keep your cost of diagnosing the problem down by saving the mechanic a lot of wasted time looking for a cause that other people have already figured out. This doesn't mean it will be fixed under any kind of warranty. It suggests whatever problem you're having will likely be solved by replacing the computer with one that has been modified, updated, or redesigned to address some concern. If the problem was safety-related, a recall would be issued and the parts and labor would be covered by the manufacturer.

Caradiodoc
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Sunday, April 4th, 2010 AT 3:02 PM
Tiny
SVNOVA
  • MEMBER
Thanks caradiodoc. Here is what happened. For last one week Check Engine light was on. I took it to the mechanic and he said the code is 420 and it needs new catalytic converters. And also he checked out the technical bulletin and according to it, the ECM need to be replaced and quoted $1800. He is going to try replacing ECM first and then try the catalytic converter.

I read on the news groups that Toyota had fixed/updated the ECM for this issue. And this will be covered under warranty(8 years/96K miles)
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Sunday, April 4th, 2010 AT 5:55 PM
Tiny
SVNOVA
  • MEMBER
I am referring to this from one of the forums:

There is a Technical Service Bulletin (TSB) dated 10/19/05 for 01-03 Siennas that calls for the replacement of the Engine Control Module (ECM) with a new, improved ECM to resolve the "false" PO420 code, which is due to the fact that Toyota had lousy, defective programming in the original ECM. This is a warranty item up to 80K mi. Or 8 years, but if you miss the warranty period, Toyota won't help you even though it is clearly a manufacturing defect, and the ECM costs $1600 to replace. It can't be reprogrammed or rebuilt, and there are no aftermarket suppliers of the replacement ECM.
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Sunday, April 4th, 2010 AT 6:15 PM
Tiny
CARADIODOC
  • EXPERT
I'm crossing my fingers you were quoted this amount from an independent repair shop. If so, head to a Toyota dealer for a second opinion. They have a vested interest in keeping you happy so you'll buy another vehicle from them. There might be something they can do to bring the cost down. Also, I don't know if this applies, but when I worked for a really nice family-owned Chrysler dealer, they had a fund provided by Chrysler for the dealer to use at their discretion to pay for out-of-warranty repairs. They reserved those bucks for their regular customers and for certain hardship cases, but I can also share that people who were screaming or angry usually didn't get that help.

If you were already at the dealership, don't be afraid to try a different one. I read stories all the time about people getting their problem handled at a different shop. That happened to my mother many years ago. The dealer wanted to charge her $125.00 for a Chrysler engine computer, (that was in 1980). I was in the process of buying a new car from a different dealer. He said there was still 10,000 miles left on the computer's warranty and if the first dealer wouldn't take care of it, he would.

By the way, I wouldn't exactly call this a defect, but, when it affects the Check Engine light and emissions, the government watches really closely. If this is a known and common problem, there may be a government-mandated recall. If there is no formal recall for the specific issue, that would suggest it is not real common, or at least it doesn't happen in a very high percentage of vehicles. Unless it has changed in the last few years, the government mandates everything emissions-related be warrantied for 50,000 miles. If Toyota is going to 80,000 miles, they are helping out a lot more customers than they would have to. Still, $1600.00 seems like an awful lot for a computer. I won't buy a new car because I don't want to risk having to buy a $700.00 computer!

One last comment I like to share whenever I have the chance, (please don't read anything into this), is to approach the dealer or independent repair shops as your partner in solving this problem. Too many people consider them the adversary when in reality, the sorry fellow behind the desk is bound by his supervisor's policies. When they see you are not satisfied, but not angry, they will be more eager to walk you to the next person up the chain of command. Typically that will be the service manager who will listen to your story, then likely consult with the person who handles the warranty claims. Between the two of them, they will figure out what they can do. It is in their best interest too if they can get Toyota to cover at least part of the cost of repairs, but they are stuck in the middle if they know that won't happen.

The next step up is the business owner although he usually relies on his service manager to make the right decision, otherwise he wouldn't need him. The owner might even know less than the service manager about warranty issues. His job is to surround himself with knowledgeable people so he doesn't have to be the expert. He WOULD be the likely person though to set up a meeting with the district manager. In Chrysler's case, they have one for each state, and they visit each dealership about once per month. Their purpose is to help customers by ignoring policies the dealer can not. Here again, threats and anger, I'm guessing, won't be as effective as pointing out you are a loyal customer, as are most Toyota owners, and you will buy your next vehicle from a company that at least tries to help you out. On the flip side, I guess it goes without saying the computer lasted for many miles and many years without a problem so maybe there won't be anything they can do, but it sure doesn't hurt to ask.

To shift gears for a second, there is still the possibility the computer isn't actually causing the problem. Perhaps the catalytic converter is not working properly or one of the oxygen sensors is defective. To base a diagnosis, especially such an expensive one, solely on a technical bulletin might be jumping the gun. How will the mechanic explain it if the fault code comes back after buying a new computer? I'd want to be awfully sure before I asked a customer to pay that kind of bucks.

Caradiodoc
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Sunday, April 4th, 2010 AT 8:08 PM
Tiny
GEOFFREY HYDOCK
  • MEMBER
I also hane a 2001 Sienna with 215,000 miles on it. The 420 code would show up but clear out on road trips. Then I also got and evap code so the light would not clear out anymore. Took van shop to get them fixed, evap code taken care of but the new $1200 Toyota cat threw the 420 code a month later. Now they put on new mass air flow, again 420 code. Now they get toyota to trade it out for a new one. Made it 7000 miles this time and again 420 code, so now we try rear o2 to see what happens. Again 420 code is back! Just saw the post for TSB for bad ECU, wonder if that has been my problem all along? Thank God I only paid for cat and they have eaten the cost of everthing else. I wonder why the dealer ship did not check for TSB when they wanted to trade it out after four weeks. Now I wonder if I am going to have to drop $1600 for the ECU? I don't know if the van is worth it!
Geoff
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Thursday, February 9th, 2012 AT 5:47 AM
Tiny
RIVERMIKERAT
  • MEMBER
Hey Geoff, it definitely sounds like you need to at least have the ECM reprogrammed/flashed, if not replaced. You can use a used one.
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Friday, February 10th, 2012 AT 6:21 AM

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