ODBII - MEFI-4 or MEFI-5?

[rkmfl]

I have a 2005 Supra Launch 21V with the upgraded 340 motor (ETX headers).

Every now and then the motor will set itself to run in protective mode, for things as simple as the battery being disconnected. My shop connects a diagnostic reader (like an OBDII reader) and determines if the code is just from the battery, for example, then "resets" it and re-tests.

I'd like to buy my own code reader so that I can save the 2-hour roundtrip to the shop, just to have them plug-in the reader and hit "reset".

Problem is, I am not sure if the 2005 Indmar 340 uses the MEFI-4 or MEFI-5. If it requires the MEFI-5, I'm probably out of luck because that appears to require a $600 box, but if it's MEFI-4, it seems I may be able to buy a $60 tool off eBay to diagnose and reset it.

Thank you in advance for any ideas!

[wotan2525]

This should probably help you...

http://mefituning.com/mefi-ecu-table

And if you do have a MEFI4 or lower, you can make your own trouble-light tool.

http://www.offshoreonly.com/forums/d...an-1-00-a.html

[docdrs]

http://www.rinda.com/acro/tech_specs_v6.pdf

here is what you want but I believe it is mefi 5 so I guess your out of luck. you could buy one and rent it out

[rkmfl]

@wotan2525 - Thank you for the ECU table. Unfortunately those part numbers don't relate to the part number I have on the Indmar ECU. However, your idea did inspire me to write the ECU number down and call Indmar, which led me to my answer. For anyone stumbling on this post, here are the details.

On my 2005 ETX 340 engine, the Indmar ECU# is 055673. This is a MEFI-4B. The person I spoke with at Indmar mentioned that when you see two harnesses going into the ECU box, that is a pre-MEFI-5, and when you see 3 that is a MEFI-5.

@docdrs - Yes, the Rinda is the $600 box I had mentioned required for MEFI-5. However, what I was asking is the specific version of MEFI used on this model. In my case, it's a 4B, which indicates that I can use a $63 box from "Michigan Motorz". At least I'm hoping it will work!

If anyone here has experience with the $63 box or an alternative, I'm interested in any feedback you have.

Thanks again for the input!

[beast 496]

Go and check out the Rinda web site. You can buy the standard scan tool and the adaptor for either Mefi 4 or Mefi 5. I have multiple adaptors, probably 8 differant versions, and the latest update software for the scan tool. Extreamly invaluable tool. The adaptor for the Mefi 5 is expensive, but if you want to service this engine, a Catalyst engine, it is a must. If you don't have a Cat. you have mefi 4 software. Al

[rkmfl]

@Beast - I contacted Rinda and purchased their cheap flasher. They explained this will not reset the codes, but at least I'll know if/when codes are being thrown.

For anyone else stumbling on this, it's only $39 + Shipping from Rinda.

One more thing .. On the more expensive model, can you determine fuel pressure? For example, I think I have an issue where the fuel pressure is low and this would be a simpler way of determining if that is true.

Thanks again for the input!

[beast 496]

on a mefi 5 the computer monitors fuel pressure, on mefi 4 and lower it does not. I suggest buying a mecanical hi pressure fuel gauge. Less than $50.00 for a good gauge, I bought mine at Napa several years ago.