Jester Chrome ECU Replacement Flashable / Tunable ECU


Jester Chrome ECU Replacement
Flashable / Tunable ECU
1991-1999 3000GT & Stealth


This is an alternative to the factory ECU!

Unfortunately for pretty much EVERY 3000GT/Stealth owner, a failed ECU is a "definite" as the original ECU's were not built with long-life capacitors and other components. This means that the capacitors are "destined to fail" leaving you with a car that can vary from running erratically to not running at all. 3SX has long offered our ECU rebuild service that gets your original unit overhauled and restored to "like new" condition to get your car back on the road, a successful option that works very well as it is applicable to ALL the models and they are bench-tested by the builder before being returned to you.

Other options for a dead or dying ECU are to simply purcahase a NEW OEM ECU, which can carry a hefty price tag, and some models are no longer available. This bigger disadvantage to this option is you are still limited in tuning capabilities and must run "piggy-back" tuning devices such as the Apexi AFC Neo or MAF Translator setup.

Alternatively to OEM, you can go full-bore and get the AEM standalone ECU with sensors and get your car tuned. While the more expensive option, this gives you FULL tuning capabilities for whatever size injector and turbo combination you want to run, from a basic stock setup to however much horsepower you can generate!

NOW, after several years in development and testing, there is an excellent ECU option! The Chrome ECU serves as a stock-replacement ECU, so you can replace your dead OEM ECU with a Chrome ECU and keep on driving with minimal installation effort. OR! Or rather... AND! You can also get the Tactrix OpenTune ECU Flash Module and software and actually modify many aspects of the ECU's settings. In other words, you can TUNE your car to suit your fuel and turbo installation needs! And like the standalone AEM, you can tune for different fuels you want to run, be it pump gas, 100, 116, E85, etc. Obviously, running alternative or higher octane fuels will require custom tuning and supporting fuel modifications.


’91-’93 Plug Type

  • Plug and Play for your OBDI 3000GT/Stealth
  • Active Exhaust is Retained
  • Ships Pre-Installed with the Most Recent Version of Chrome Installed
  • Ships with Extra Pins and Pigtail to Enable OEM ’98-’99 Flash Features – WBO2 datalogging, boost datalogging, the No lift to shift(NLTS) clutch switch setup, etc… All through the ECU!

5/13/14 - NOW FOR NON-TURBO ALSO - The Chrome ECU is now available for the 91-95 Fed-Spec NA cars using this same 3-plug harness/ECU. This includes the VICS control as well (variable induction butterfly's in the

intake plenum).

1991-1993 Jester Chrome ECU


’94-’97 Plug Type

  • Plug and Play for your OBDII and OBDII Hybrid 3000GT/Stealth
  • Switch Between ’94-’95 and ’96-’97
  • Switch Between Fed and Cali spec
  • Active Exhaust is Retained
  • Ships Pre-Installed with the Most Recent Version of Chrome Installed
  • Ships with Extra Pins and Pigtail to Enable OEM ’98-’99 Flash Features – WBO2 datalogging, boost datalogging, the No lift to shift(NLTS) clutch switch setup, etc… All through the ECU!
  • Will pass OBD-II emissions tests like an OEM ECU


1994-97 Jester Chrome ECU


’98-’99 Plug Type

  • For Anyone Who Already Owns a Wiring Harness Conversion or Who Owns a ’98-’99 Who is Wanting to Go Back to a OEM Flash ECU
  • Ships Pre-Installed with the Most Recent Version of Chrome Installed
  • Will pass OBD-II emissions tests like an OEM ECU

4/13/2016 - NOW FOR NON-TURBO ALSO - The Chrome ECU is now available for the 98-99 SL NA Cars using this same 4-plug harness/ECU. You will want to purchase the 98-99 VR4 ECU in the drop down menu.


NOTE: With the exception of the 91-95 NA, the above options currently do NOT support the VICS (variable induction control system) on the DOHC Non-Turbo engines.


Q: Do I need do any modification or wiring modification on the first generation 3000GT to install and tune it?
A: No modifications are needed to install these ECUs. It is a fully plug and play flash ecu. There are two wires supplied with the ecu that are installed into the existing obd1 plug in first gen 3000GTs to allow flashing and datalogging through the stock OBD1 port. Also, while not necessary you can rewire the stock fans to the ECU to allow for ECU controlled fans like all 94-99 3000GT had.

Mini FAQ

Q: Can I run a piggyback tuner with the Chrome ECU?
A: Seems this topic comes up a lot. Yes you can do this. In fact, it is recommend it for 2 reasons: Both the ARC and the MAF Translator give the advantage of an aftermarket free flowing MAF AND you can keep the live tunability and simplicity that you otherwise lose via tuning straight with the flash. You'll actually find your car will drive better just using the flash ECU to set the injector scaling and fine tuning the timing table. Throttle response is smoother, start up is better and best of all, there's no limit to what size injectors you can run. You literally get the best of both worlds.

Q: I have a non-US GTO, will this work?
A: Yes, you use the 91-93US flash ECUs on the GTOs 91-98. You will see on the label in the ECU. They also work with the immobilizer GTOs. Note: Please let us know what year your GTO is so we can provide the correct cables for your vehicle.

Q: Can this ECU manage boost control? I don’t know if this car has a OEM boost solenoid control.
A: Yes, these pnp flash ECUs can handle boost control using stock equipment.

Q: You said the ECU can datalog the wideband, I imagine that can not manage AFR signal or table.
A: After the wideband is wired into the ECU you can edit the wideband scaling table to use any 0-5v output wideband available.

Q: To retune the ECU, I have a lot of experience with tactrix cable using at EVO, Subaru, RX8 and MazdaSpeed. Which program must I use for tune this ECU? Ecuflash or chrome?
A: Tuning is very similar to the Evo and Subarus. Evoscan is used to datalog the ECUs and Ecuflash is used to reflash the ECU. Chrome is the name of the modified ROM on the ECU. The definition files for Evoscan and Ecuflash used to datalog and reflash the chrome ECU are supplied.

Q: Can I use multiple tunes/maps, like one for pump gas and one for race gas or E85?
A: Yes. Simply save each tune/map as an identifiable name on the tuning PC/laptop. When you want to change fuels, you simply load the alternate tune/map to the ECU.

Q: Can I use this on my sohc if I put a turbo on it?
A: It would not be a easy plug n play solution. You could potentially switch the sohc distributor over to a coil pack system, then use a SL or VR4 ecu. But it is only theory never been done.




The Chrome ECU comes with a little safeguard... The ECU itself comes with a 2 year THREE year warranty on the ECU itself. It also includes a 6 month "brick" warranty, whereby if it is rendered unusable (i.e., it becomes a brick) within the first 6 months of use, it is covered. This is something that can happen during the flashing process (loading the ECU software to the ECU).



TUNE with Tactrix!

While the Chrome ECU gives you a replacement ECU, one major benefit of the Chrome ECU is that it gives those who are modifying their engine to get more power the ability to actualy TUNE using that very same ECU!

The Tactrix OpenPort 2.0 is the ECU Flash Control Module that gives you the ability to actually let a computer talk to the Chrome ECU and make changes to the different maps and settings within the ECU.

CHROME MAF Now Available!!!

Chromed Jester Maf

The stock 3s maf is only good to about 400-450 hp due to the limitation of the internal sensor. The sensor could only read so high.

The evo 8/montero maf was a popular upgrade because the internal sensor could read much higher. The drawbacks to the montero/evo maf sensor was a much smaller maf housing. This restricted airflow. It also required a plug adapter and an intake bubble adapter. You also has to change the maf size and adder in the rom.

This maf combines the best of both worlds. It has a larger 3S maf housing with the high reading evo sensor. This equates to about a 20% airflow increase over the evo 8 maf. It also doesn’t need a plug adapter or an intake bubble adapter. The maf can be used with the stock settings in the VR4 or SL rom. The only recommended change is to increase the Hz values in the VE table for higher airflow.

**You will want to read your 3SX Invoice for further instructions.***

Note: If you don't want your old ecu sitting around. Send it back to 3SX for a $50 store credit. This offer only applies with a purchase of a chrome ecu.

** Jester Chrome ECU's are NOT RETURNABLE, per our policies outlined HERE **

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