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Need advise on upgrading dead piggyback...

2801 Views 13 Replies 3 Participants Last post by  TUNDRA10X
Need advice on upgrading dead piggyback...

Dear Boosted brothers:

The 2002 Tundra abruptly and rudely died and came to a rolling stop on the freeway last week... Check engine and A/T temp light came on...No noise, no nothing. Re-start was a nogo. After a good look on the ground and under the hood, a fluid check and no weird smells or anything I could see out of place, I called for a flatbed. Two and a half hours later I'm back home and just as stumped.

So, off to to shop it goes and after a bit of diagnosis it seems the piggyback has probably died as it will now start and run in the shop with it disconnected, but not when it's plugged in. The shops' sources say they don't exist anymore in inventory. (go figure)

The mechanic called UnderdogRacingDevelopment today and confirmed they still make black boxes with a new plug-in harness (Map-ECU3 Fuel and Ignition Control - UNIVERSAL) for our application, but it will still have to be mapped or tuned on a laptop or dyno. A used Toyota TRD piggyback box may still be out there for sale, or another company may be a better choice.

Am I or Cary the mechanic overlooking anything obvious? Anything to pass along to him as suggestions or is there another company we should be calling?

Thanks in advance.
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Re: Need advice on upgrading dead piggyback...

I have a MAP-ECU2 in mine, and it works well for a standard TRD SC install, although it will need to be tuned by someone that understands how an OBDII ECU works. The TRD piggyback, is probably the bottom end for what is available now, and from what I understand they were never really a great solution.

I'm about to move on from the MAP-ECU, due to my need for more power. I have hit the limits of what it can do without upsetting the stock ECU.
Re: Need advice on upgrading dead piggyback...

Comforting news. Tried to order one by phone on Friday, but it seems everyone from URD had gone home early! Will try again Monday morning and update when it's in and up and running.

Thanks again.
Re: Need advice on upgrading dead piggyback...

While you have URD on the phone ask about the UCON EMS for your truck. It is probably not available yet, but worth a shot.
Re: Need advice on upgrading dead piggyback...

Dear Boosted brothers:

The shops' sources say they don't exist anymore in inventory. (go figure)
Tundra10x, I have two piggyback ECU's. One on a S/Cquoia and one that I have been saving for 10+ years as a back up.

I am in a similar situation as the Sequoia started twice in a row but refused to start the third time in the driveway after hitching up a boat to go fish a night tournament. I am awaiting parts that should arrive tomorrow or Friday and hopefully it will start again and run.

If not, I suspect a trip to the dealership may be in order and that will probably require additional funding so I would reluctantly offer this spare ECU. Let me know if you are interested.

PM to be sent...
Re: Need advice on upgrading dead piggyback...

Will try again Monday morning and update when it's in and up and running.
10X how did you make out?

So far, Great! Ordered the Underwood Racing Development (URD) computer first and found out after that the tuner (XactDyno) and the installer (Cary's Auto) were not comfortable with installing and Guaranteeing the installation and tune. Picky people, I know...It's still in the box, uninstalled.

They led me to Unichip. Ordered, installed and tuned in September 2014. Results speak for themselves: 370 lbft. of torque/ 350 Hp. No worries and no problems for two and a half years with realistic numbers for a daily driver. It's fun and power is there when you need or want it; at least for a fat girl...

With semi-sane driving habits it can last a long time...The supercharger has been on since May of '05 and has over 55,000 miles on it.
Still brings a big grin and an elevated heartbeat every time I stuff it... :grin2:


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Last night I got my 2002 Toyota back from the dealership after a lot of troubleshooting and repair to the knock sensors and 9th injector harness and the replacement of both knock sensors ($225 each!) the total was over $1,800.

Essentially they just reverted back to the stock ECU; I guess leaving the supercharger, S/C ECU, pigtail and ECU connector disconnected behind the glove box (I need to verify that it is still there). When the service writer said there was "a problem with the supercharger ECU or pigtail harness", I remembered that I had the spare one that I picked up new in 2006! I drove all the way home got the ECU and drove it back to the dealership. The next day they said they tried it and the engine still would not run... Right now I am driving it on the stock ECU and it seems to run well but I have not tried to make the 'jump to light-speed' just yet.

Yours sure seems to be strong but I notice several other up-grades like the headers. intake and exhaust. I have 138,000 miles on the vehicle and most of them are 'blown miles'.
I checked out the UniChip web site and it looks like one of their ECU's cost about $600. Then you had to have it dyno tuned; how long in dollars did that take?

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Cary charged me $890.00 for the Unichip install and that included the sublet tune at Xact Dyno.

Cary wasn't completely happy with the first tune. After the test ride with just the two of them and the test equipment in the front seat, Xact Dyno agreed and put it back on for a minor re-tune. The second run was good to go. Good people bring good results.

Dealing with dealerships when doing out of warranty work can be a bit of a gamble in cost and diagnosis...Finding a good independent repair shop is wholly dependent on your luck or location. I probably would not recommend chasing the original Toyota TRD bandaid of a piggyback system now that it's all out of your pocket.

Just as @ats_scott mentioned earlier in this thread, there are better solutions out there. The spare URD MAP-ECU2 I have will work fine if someone has a tuner/installer to do the install...The Unichip I have is obviously also a good choice and ended up being mine. Good luck. There are people out there that do this stuff with a passion and have the knowledge and the tools to keep us running. My mechanic is still more important than my doctor...I see them both with about the same infrequency.

Well, at least for now.


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Since I got the truck back from the dealership in April, it has been running, slowly, on the stock ECU.

I'd like to get a Unichip and have it tuned as necessary. Any suggestions or advice?

Hang in there! Order your Unichip and have one of the tuners in Georgia install and tune it for you...

Batlground Motorsports LLC (Tuner)
1770 Atlanta Road Southeast
Smyrna, GA 30080

Z 1 Motorsports
2877 Carrollton Villa Rica Highway
Carrollton, GA 30116-5525

Unichip Automotive Performance - Unichip Tuners World Wide

Use my post above for price negotiations. Don't stay in limp mode...It's only time and money.

The lack of money is the root of all evil.
Mark Twain
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Would anyone here know the 'trick' to opening up one of these Supercharger ECU boxes?

Electronics Electronic device Technology Material property Gadget

I'd like to send it to a guy on eBay (SpeedometerRepair or similar?) who 'repaired' my factory (main) ECU but before doing so, I'd like to see if any components are fried, or if the Harness or Junction Box has gone bad.

Technology Electronics Electronic device Gadget Box

What is the secret to opening the ECU up? It looks like the panel with the serial number would just slide out but there must be a release somewhere that I am missing.

Box Electronic device Rectangle

Also, I saw where James had recommended an URD ECU that was 'self learning' -I guess; that would set and adjust Air fuel Ratio and Timing (for 'only' about $1,600). Is this what you tried 10X? Anyone else out there running this unit?


Apologies for double posting but there are far fewer S/Cquoias out there...
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Sorry to hear your still in limp mode...No clue on how to open one up. My old one is still in a box on the shelf.

I would send it in as is and let the repair guy decide if it's worth fixing. We never got to the point of installing the URD2 unit.
(It's still new in the box and for sale in the exchange)

You're welcome to my old one if yours is fried beyond repair, but I don't know what was originally wrong with mine either...
Again, don't give up. The repair route is actually quite novel! It's nice to know someone out there is attempting to fix them.

All considered, that would be least expensive way to go, but you'll have no more or less peace of mind re-installing the factory piggyback.

"Endeavor to persevere." :grin2:
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