A few weeks ago I was having major problems with 'throttle lag' and slow acceleration in my Max. More often than not, when I would step on the throttle the car would lag and pull like it was a 4 cylinder Honda. It was absolutely terrible. The engine felt like it had no power whatsoever. I was also getting terrible gas mileage; 17 mpg (city driving) per tank. I initially thought my MAF was getting ready to blow again so I kept waiting and waiting for it to give however this never happened. It's also worth mentioning that the infamous SES light never came on once throughout my ordeal.

In an effort to help remedy my problem I first I uninstalled my Apexi SAFC II thinking that maybe this was a contributing factor, however I was wrong. I then tried unplugging the battery, not just overnight, but for an entire weekend when I was away from home in an effort to reset the ECU, even though I am a firm believer that this does no good whatsoever based on personal experience, however I figured it couldn't hurt. Once again, this did absolutely no good and my problem persisted.

A day or so later while reading another thread I came across a website for newly formed company called Technosquare that sells ECU upgrades for a variety of cars including the 350Z. While browsing their site I came across instructions for resetting the ECU on a 350Z. You can view the instructions Here
I search and browse the forum here fairly regularly and I've never come across an ECU resetting procedure such as this. I figured since the Max is a close cousin to the Z, why not give it a shot to see if it works.

I first followed the steps for resetting the ECU as outlined on the site. I was delighted to discover that the procedure worked on my Maxima and I successfully reset my ECU with confirmation (If you follow the steps correctly you'll see what I'm talking about). Once I reset the ECU, I then reset the Accelerator Pedal Release Position and the Throttle Valve Closed Position Learning via the steps outlined right below the ECU reset procedure on the same site. I do recall viewing several threads on the forum including This one in regards to resetting the Throttle Valve and Accelerator Pedal and the instructions were exactly the same. After all this was completed I went for a spirited drive. Here are my impressions after one week:

1. I must say I LOVE my Maxima again!!!!
2. The throttle is now smooth and very responsive. There is no more 'lag' or loss of power.
3. The car pulls hard all the way to the redline with no hesitation. It's great to feel the full potential of the car once again.
4. Gas mileage has improved significantly since performing these procedures. On my last tank I averaged 22 mpg city driving vs. 17 mpg before.

I've read several other posts recently from other members describing symptoms similar to mine. To all those members, you may want to give this a try. It certainly helped me out and it may work for you as well. And to all members, you now have instructions on how to PROPERLY reset your ECU.

 

hmmmm, thanks for the info, I may try this later this week

 

seems like you will go through a half tank of gas doing this. is it best to put it in park or nuetral when doing this?

 

I don't think you're supposed to start your car...just turn the key to the "On" position...one click short of starting the motor

 

just wondering...can i do this although i don't have any of the problems....maybe i could feel a difference...who knows....nothing harmful can be done to the car by resetting the ECU rite???
thx alot ppl

 

i have a 2000 max se, i have tried it several times and i have a stop watch i really just cant seem to get it. my ses isnt on at the moment so i dont know if thats necessary, i always put the key in the ignition put it in the on pos. wait 3 secs the sec it gets to the 3rd sec i press gas release 5x then wait 7 secs right on the 7th i put foot on gas for the 10 but nothing i have tried it several times. please notify me if it doesnt work for 2k's

 

BrandonSE, this will only work on 2k2+ because of drive by wire system.

 

U see that part where it says "Throttle Valve closed position learning"? I think our cars do this by default everytime you shutdown your car. I know my car does that because everytime i shut it down i hear it making that same clicking noise it did after i performed that part. Unless it's doing something more intense when u do this.

 

10

 

nice.......

 

How will I know if the first reset (the ECU one) is correct if my CEL is not on to begin with?

 

When u do the procedure, in the middle of it your ECU will start flashing slowly, then it'll start flashing faster, then it'll stop flashing and when u restart it's gone. If u don't do it right, it never starts flashing. Took me a few attempts but it did it. I'll update a review tomorrow.

 

Just a thought.....the 2002 Max and Altima SE had a TSB for this problem which you should have had done to correct this. Will this procedure over ride the New Program that Nissan has developed to rid us of this problem. Resetting it is only going to bring you back to the origional setting which causes hesitation. Right????
On a side note.....I had the TSB done on my car...It made no difference what-so- ever. The engine still has a mind of its own and hesitates at will.

 

Your the man I had to take my shyt off last night because I'm going in for service tomorrow and didn't want to deal with the bumba$$ service writer. After I got done the SES light came on , anyway that procedure WORKS! Just follow the instructions and it WILL work. Thanks!!!

 

Good one!

Wonder if this will reset my advanced timing...

 

I have done this easy ECU reset procedure on my G35
several times with success. This procedure is for the
"drive by wire" design autos. I also have a 2000 Maxima.
I don't believe the 2000 Max is a "drive by wire" car.
Someone please correct me on this.

 

this worked for me.... i had my SES light on i tried 3 times and on the third time the ECU reset for sure. i did all the others after the fact..... deinately feels diff. car needs to learn my driving style and mods again but this was definately nice to know!!! THANKS!!!!

will

 

Will the Techtom Programer work on our car? http://www.technosquareinc.com/flashecu.htm
The lowest pic says Nissan.

 

For those of you with the Timing Advance trying to get past the 2-3degree wall, you should try this once you hit the wall and can't increase further. Then try again.

 

Yes, there is a TSB for this problem. I just recently had it performed on my '02. They replaced the MAF sensor and reprogrammed the ECM.

NO MORE HESITATION! Now it pulls smoothly and I can't even feel the gears changing(I'm auto) It does feel like a whole new car!

 

I reset my ECU today and will be going in for the TSB for "lack of power" tomorrow. If i get the ECU upgrade and then reset my ECU at some point in the future what will it do to the new upgrade??

 

Yeah, I've done this before. The timing it tough, took me a few tries, but it works. Also, someone else on the org has these instructions on their website, that's where I found them. I want to say BigDogJon? I forget.

 

For those of you who have done the advanced timing mod. Who did it and what changes di dyou notice? thanks

 

I was just thinking the same thing?

 

Anyone know if there are reset instructions for a 2000 Max?

 

so guyz....say when u install some performance mod...do u reset the ecu to bring out the potential or no...thx...

 

not for all mods. usually for like an intake or headers it'll make a diff, or a super/turbo charger..

i doubt you need to reset it for mods like exhaust or anything after the engine

 

First, resetting the ECU via disconnecting the battery(if possible on 2K2+) or using the top post method will NOT cause any TSB reprograms or timing advances to be lost

Second, resetting the ECU after a mod like an intake or exhaust will cause the ECU to re-adjust the A/F ratio and maybe the ignition advance(not sure) for casual driving, ie non-WOT or aggressive throttle changes. However, if you put on a mod and immediately run out to a dyno or go WOT, you don't have to wait for the ECU to compensate to see gains. Open-loop A/F and timing maps(unless maybe there is spark knock) are set at the factory and do not change as the ECU learns. Basically, the open-loop map is pig rich and any mod you do that increases airflow will take advantage of a slightly leaner condition.

 

I have a 2k3 max, so should I go in for the TSB first, or just reset my ECU. And if I reset my ecu should I just disreguard the TSB? I just wondering. I am reaching my 12000 point where I will have to start paying for the labor, help!

 

During non-WOT driving, appx how long would it take the ECU to remap the A/F ratio? I would think it would happen relatively quickly, say, 50 miles or less?

 

anyone know how to reset the ecu on a 2000???

 

It's a constant. It will always make adjustments based on how you drive. Or should I say how you've been driving.

 

Since it is constantly variable and "learns" your driving style, there would still be some form of a timeframe for it to adjust for the changes. With an intake, most people are more "heavy footed" due to the sound. This is a change of normal driving style, thus the ECU will have a learning curve. I assume conditions, driving style, and amount of travel depict how long this process would take.

So, I guess the question would be.....What is the best way to get the ECU to learn a new driving style after a change/mod. Reset ECU or let it recalculate it automatically....

 

I just got back from the dealer who performed the lack of power TSB.... WHAT A DIFFERENCE!!!! If you have an 02 or an 03 youhave GOT to get this done. What will happen now if I reset my ECU myself??? Will teh new upgrade be lost???

 

I don't know, however unless you actually hit a particular point while driving, ie load/rpm, it can't over-write the old value. So, I wouldn't think it's "50-miles" or some other specific distance.

Each time you start your car the ECU goes into "learning mode" to compensate for the latest conditioins, ie weather, temperature, altitude, etc. and compensates. There are short-term fuel trim/enrichment adjustments that are aggressively trying to shoot for the target A/F ratio and there are long-term adjustments that compensate for things such as major changes in winter/summer temps and altitude. How rapidly these short/long trims change or how they interpolate between new/old points, I don't know. That's something only Nissan designers would know or if you had map tracing equipment.

As far as resetting the ECU goes, you're basically erasing any previously stored values and FORCING the ECU to start with the factory baseline maps. Then as you drive, it's going to be rapidly over-writing the factory points to hit the target A/F for a given load/rpm. Since there is no long-term data to use as a baseline, the short-term trim is going to rapidly affect long-term trim causing the ECU to react and learn faster.

 

Thanks, Ice. That's pretty much what I thought. To ensure proper learning of mods, it would "seem" better to reset the ECU and allow it to quickly learn its new settings instead of waiting for the ECU to adjust. Again, this is dependant on a wide range of variables..

 

I actually understood what Ice said.... and thanks for the info. I learned a lot. Im taking my car in for a ECU update next week.

 

I did this during lunch and notice a huge improvement. My car seemed to have some hesitation in first and second. Kind of like a jerky feeling. I noticed immediately afte making this cange that the power came on smooth. I will admit that it took me 10 tries to make it work.

 

Hey all,

To answer a couple of questions:

1) No this ECU reset will not affect ECU flash upgrades performed in the past. It resets codes and emissions information. The engine management code that runs the engine is not affected by this procedure.
2) It will not re-set a timing advance.

What this procedure does is it resets "workspace" items in the ECU including error codes, OBD II stuff, and recent trip information in the OBD II banks.

I find that the throttle position reset procedure does the trip for those who still suffer from mild, inconsistent hesitation.

Regards,

10e

 

Oh,

By the way, IF you have felt hesitation before and did not get your ECU upgraded (via NTB03-022 or 023) the effect will not last for very long.

When I did this before the upgrade, my car still sucked after about 50 miles of driving. After the upgrade it's been awesome.

Good luck,

10e