I was reading the forum here and noticed you guys talking about resetting the ECU on your GS's. The SC guys do the same thing to try to improve the learning mode also.. I got around it and gained a lot of power by having Leo from Weapon-R install an intake and ECU upgrade on my car. He got a HUGE gain from the under-tuned 1UZ-FE motor, a good 50 whp altogether. He makes a similar upgrade for the GS400, which is worth 15 whp alone, around 25 with the intake. Torque gains are also good, 27 ft-lbs from the chip alone. Plus this thing works with the car's ECU so it isn't interfered with by the learning mode. You can bypass the module by plugging in a bypass plug, so you can smog your car (I'm in California) or in case the dealer is working on the car.

 

MadMax or anyone.....Can someone give more detail on the ECU learing mode. Is it only on certain models or later year models. I do know for a fact that at leats the firs years of the SC300 does not have a learning ECU, thus resetting the ECU doesnt do anything except erase your memory settings. Thanx



gadgetSC

 

The so called "learning mode" came about with the advent of on board diagnostics, especially prevalent in cars with OBDII. I believe '97 was the transition from OBDI to OBDII, so most cars built since '97 have it. As it was explained by one of Nissans top engine tuning guru's, learning mode is a reserved area of dynamic memory within the ECU that reads current air/fuel and other engine requirements, and basically averages each component over time and stores that reading in this memory. So, if you drive like a madman all the time the ECU senses this as a standard driving pattern and stores these variables, that way your car always "feels" like it has more power available. Consequently, if you drive conservatively, the ECU will learn this mode. Keep in mind, it is very hard to drive aggressively 100% of the time, so without those constant high requirements, the ECU will eventually "detune" towards more conservative settings.
By disconnecting the battery, you clear out the ECU memory, so it now has no stored info to go on, and is threfore more responsive until the memory gets repopulated. This is constant process, of learning and relearning based on engine needs. Also worth noting is that there are hardcoded limits that the ECU will absolutely not let the engine operate above or below, and these are based mostly on emmission standards for the vehicle. That is why there is only so much tuning that can be done to these cars.

 

That's why on my car, which is OBDI, the ECU alone was worth 38 horsepower. With the OBDIII cars, they're only getting like 13 horsepower.

 

Mumbles, thanks for clearing that up.


gadgetSC

 

I don’t know about other references to the “learning” mode and ecu but for the most part what was being discussed was the ECTi transmission and it’s ability to “learn” your driving habits and adjust shifting to fit. That is the ecu fuse that was removed/replaced.