How JustAnswer Works:

  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site.
    Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.

Ask Eric Your Own Question

Eric
Eric, Automotive Repair Shop Manager
Category: Toyota
Satisfied Customers: 24317
Experience:  20+ yrs. experience as repair shop manager and technician.
3195632
Type Your Toyota Question Here...
Eric is online now
A new question is answered every 9 seconds

2002 Sienna: dealer says..ecm..the catalytic converter and o2 sensors

Resolved Question:

My 2002 Sienna is giving a p0420 code, which means the catalytic converter is performing out of spec. The dealer says I need a new ecm for about $2000 and that the catalytic converter and o2 sensors are ok. Is it possible to get a new ecm myself and replace the "defective" one myself. And would that really solve my problem?
Submitted: 4 years ago.
Category: Toyota
Expert:  Eric replied 4 years ago.

HI,

 

This is actually a known problem with Toyota and they have issued a Technical Service Bulletin on this issue. It is covered by an 8yr or 80,000 mile warranty and does require replacement of the ecm, along with new software programmed into it. Because the software is proprietary, it can only be done by a Toyota dealership. Not even us independent shops have access to this software.

 

ENGINE
EG047-05

 

October 19, 2005

Title:
M.I.L. "ON" DTC P0420

 

Models:
'01 - '03 Sienna

 

Introduction

Under certain driving conditions, some 2001 - 2003 model year Sienna vehicles may exhibit a M.I.L. "ON" with the following DTC:

^P0420 (Catalyst System Efficiency Below Threshold [Bank 1])

 

The Engine Control Module (ECM) (SAE term: Powertrain Control Module/PCM) logic has been modified to improve this condition.

 

Repair Procedure

1.Verify DTC P0420 with the Diagnostic Tester by referring to the Technical Information System (TIS), 2001 - 2003 model year Sienna Repair Manual: Diagnostics: Engine: Pre-Check.

 

2.Replace ECM (PCM). Follow the Repair Manual ECM replacement instructions. Refer to TIS, 2001 - 2003 model year Sienna Repair Manual: Introduction: How To Troubleshoot ECU Controlled Systems: How To Use The Diagnostic Chart And Inspection Procedure.

 

3.Perform the following steps to confirm that the vehicle is repaired.

 

A.Reset the Readiness test by using the "Clear DTC" function on the Diagnostic Tester.

 

^To clear the DTC, refer to TIS, 2001 - 2003 model year Sienna Repair Manual: Diagnostics: Engine: Pre-Check.

 

B.Perform Readiness Monitor Drive Patterns for Catalyst Monitor 02S type and AF Sensor type. Refer to TSB No. EG003-02, "Readiness Monitor Drive Patterns," procedures: Catalyst Monitor (02S Type) and Catalyst Monitor (AF Sensor Type).

 

C.If a DTC is set during the above drive patterns, refer to the Diagnostic Trouble Code Chart in TIS, 2001 - 2003 model year Sienna Repair Manual: Diagnostics: Engine: Diagnostic Trouble Code Chart. Test drive the vehicle to confirm normal operation.

 

4.If NO DTCs (pending or current) are stored, the repair is complete.
Eric, Automotive Repair Shop Manager
Category: Toyota
Satisfied Customers: 24317
Experience: 20+ yrs. experience as repair shop manager and technician.
Eric and 7 other Toyota Specialists are ready to help you
Customer: replied 3 years ago.
Ok, I'm finally ready to bite the financial bullet and replace the ecm (89661-08070) on my 2002 Sienna. The 2005 TSB states to replace it with 89661-08071, but I see that Toyota now shows a 89661-08072 as the current part. What is the difference between these two units? Can I use either one. If I install the new ecm myself, do I need to reprogram the computer to recognize my transponder keys? Does the Toyota dealer have to be involved in any flashing or reprogramming if I use the newer part?

Thanks
Expert:  Eric replied 3 years ago.
Hi,

give me just a few minutes to look up and see if there are any substantial differences between the 2.

Expert:  Eric replied 3 years ago.
Hi,

the ecm has been further updated on its software and you need to use the newest part in order to not have any software issues. the toyota dealer will have to program it with your VIN code and mileage. No way around that.
Eric, Automotive Repair Shop Manager
Category: Toyota
Satisfied Customers: 24317
Experience: 20+ yrs. experience as repair shop manager and technician.
Eric and 7 other Toyota Specialists are ready to help you
Customer: replied 3 years ago.
Thanks for the info. I'll work on getting the newest ecm (89661-08072). I can order a new one on the internet for a few hundred less than at my local toyota shop. If I install the new ecm myself, will the car be driveable so I take it to the dealer, or should I drive it there with the old emc and let them take care of things?
Expert:  Eric replied 3 years ago.
Hi,

you can take the ecm into your dealer, have them do the programming and then install it. It doesnt have to be installed first
Customer: replied 3 years ago.
I called my local toyota dealer, and the service person said they could program my new computer for $85 if I brought it in. So I brought it in a few days later, and I was told it had to be installed to be programmed. They wanted over $300 to install it even though I already had the panels off. So I just went home and installed it myself. Took about 15 minutes. The sienna seems to run fine as it is. What do I gain by taking it back to Toyota and letting them "program" the new ecm? I don't mind doing it if there is a benefit. Maybe I'll find something that isn't working right in a few days, but right now all seems good.
Expert:  Eric replied 3 years ago.
Hi,

the new came programmed, so no need to take it in unless you experience any problems. about the only thing to gain now would be if there were any new updates not programmed into the computer at this point

JustAnswer in the News:

 
 
 
Ask-a-doc Web sites: If you've got a quick question, you can try to get an answer from sites that say they have various specialists on hand to give quick answers... Justanswer.com.
JustAnswer.com...has seen a spike since October in legal questions from readers about layoffs, unemployment and severance.
Web sites like justanswer.com/legal
...leave nothing to chance.
Traffic on JustAnswer rose 14 percent...and had nearly 400,000 page views in 30 days...inquiries related to stress, high blood pressure, drinking and heart pain jumped 33 percent.
Tory Johnson, GMA Workplace Contributor, discusses work-from-home jobs, such as JustAnswer in which verified Experts answer people’s questions.
I will tell you that...the things you have to go through to be an Expert are quite rigorous.
 
 
 

What Customers are Saying:

 
 
 
  • THANK YOU, THANK YOU, THANK YOU!! I've got my baby back. Tomorrow I will get a tank of high octane, remove the top, go for a long long ride and enjoy my car. THANK YOU! Jughead USA
< Last | Next >
  • THANK YOU, THANK YOU, THANK YOU!! I've got my baby back. Tomorrow I will get a tank of high octane, remove the top, go for a long long ride and enjoy my car. THANK YOU! Jughead USA
  • Wonderful service, prompt, efficient, and accurate. Couldn't have asked for more. I cannot thank you enough for your help. Mary C. Freshfield, Liverpool, UK
  • This expert is wonderful. They truly know what they are talking about, and they actually care about you. They really helped put my nerves at ease. Thank you so much!!!! Alex Los Angeles, CA
  • Thank you for all your help. It is nice to know that this service is here for people like myself, who need answers fast and are not sure who to consult. GP Hesperia, CA
  • I couldn't be more satisfied! This is the site I will always come to when I need a second opinion. Justin Kernersville, NC
  • Just let me say that this encounter has been entirely professional and most helpful. I liked that I could ask additional questions and get answered in a very short turn around. Esther Woodstock, NY
  • Thank you so much for taking your time and knowledge to support my concerns. Not only did you answer my questions, you even took it a step further with replying with more pertinent information I needed to know. Robin Elkton, Maryland
 
 
 

Meet The Experts:

 
 
 
  • Chris (aka-Moose)

    Auto Technician

    Satisfied Customers:

    278
    16 years of experience
< Last | Next >
  • http://ww2.justanswer.com/uploads/MU/muddyford/2012-6-13_1204_1.64x64.png Chris (aka-Moose)'s Avatar

    Chris (aka-Moose)

    Auto Technician

    Satisfied Customers:

    278
    16 years of experience
  • http://ww2.justanswer.com/uploads/EU/eurotec/2012-6-11_13153_mpjaphoto.64x64.JPG Marty's Avatar

    Marty

    ASE Certified Technician

    Satisfied Customers:

    167
    ASE & Bosch Master Tech. 30 years experience.
  • http://ww2.justanswer.com/uploads/AM/amedee/2013-10-24_23656_Amedee1.64x64.jpg Amedee's Avatar

    Amedee

    Toyota Technician

    Satisfied Customers:

    1132
    ASE Master Technician advanced level specialist. Wisconsin certified emissions state inspector
  • http://ww2.justanswer.com/uploads/CA/caprio23/2014-4-30_201741_20121205122939.64x64.jpg Anthony's Avatar

    Anthony

    ASE Certified Technician

    Satisfied Customers:

    373
    ASE Master Automobile Technician with over 20 years exp. in this field.
  • http://ww2.justanswer.com/uploads/CR/crzydrvr00/2013-11-3_12123_246347.64x64.jpg Richard's Avatar

    Richard

    ASE Certified Technician

    Satisfied Customers:

    9
    Toyota tech. ASE Certified Technician
  • http://ww2.justanswer.com/uploads/SK/skyvisions/2012-6-9_23736_JACropped3.64x64.jpg Skyvisions's Avatar

    Skyvisions

    ASE Certified Technician

    Satisfied Customers:

    11403
    Toyota Master Diagnostic
  • http://ww2.justanswer.com/uploads/genchigenbutsu/2009-05-09_003043_cimg16431.jpg Genchi Genbutsu's Avatar

    Genchi Genbutsu

    Toyota Master Technician

    Satisfied Customers:

    3425
    Toyota Certified Master Diagnostic Technician, ASE Master Technician with L1 Advanced Engine