How to:ECU Reset,Throttle & Accelerator Position Learning

[RockyMtnTitan]

I came across this info a couple of months ago while cruising the 350Z section of the Technosquare site. With the exception of the ecu reset procedure, all the other procedures here are available in the Titan service manual. The ecu reset procedure in invaluabe, as it allows almost instant reset of the ecu's RAM instead of the usual method of disconnecting the battery and guessing as to how long you must leave it disconnected.

I think it's important to do the learning procedures periodically, as it basically recalibrates the electro-mechanical positioners, namely the throttle valve positioner and the accelerator pedal positioners. After some use, these things get a little out of whack, and get kinda lost. This can cause problems like loss of power and idle issues. This method restores the proper min/max position voltages that the ecu sees from them.

I, personally, have seen the best improvement in my engine by doing the full procedure, starting with the ecu reset, followed by the other procedures. In fact, after doing this, I got back some of my low end grunt I'd lost over the past months. I can actually catch a bit of rubber now, which I haven't been able to do for a long time! It also cured a slightly erratic idle I was having.

Give it a try, but be patient....it may take a couple (or more) tries with your stopwatch to get it right.....timing is extremely important here! (Edit: See newly added "Easy Method" below).

Note: Make sure engine is at operating temp and all electrical loads are turned off prior to doing the idle air volume learning. Don't think it matters for an ecu reset.

From Technosquare website:

Please read all instructions and be familiar with them before any attempts.
A stop watch or an analog clock with a second’s needle will be useful.

ECU Resetting Procedures

Timing is extremely critical. If it is NOT DONE within the specify time, the ECU will not reset and the Check Engine Light (CEL) will continue to remain ON. A stop watch or an analog clock with a second’s needle will be useful.

Operations Procedures

1. Confirm that accelerator pedal is fully released, turn ignition switch “ON” and wait 3 seconds.
2. Repeat the following steps (2a and 2b) procedures quickly five times within 5 seconds.
2a. Fully depress the accelerator pedal (HARD).
2b. Fully release the accelerator pedal.
3. Wait 7 seconds, fully depress the accelerator pedal and keep it for approx. 10 seconds until the CEL starts blinking.
4. Fully release the accelerator pedal (while the CEL is still blinking)
5. Wait about 10 second.
6. Fully depress the accelerator pedal and keep it for more than 10 seconds.
7. Fully release the accelerator pedal (The CEL light will continue to blink).
8. Turn ignition switch to “OFF” position and now you can start the car. The CEL light should be gone.
If the CEL light continues to remain ON, repeat the above steps. Timing is EXTREMELY critical to resetting the ECU.

Edit: Added the "Easy Method" for ECU Reset

The Easy Method:

After experimenting with different timing, and reading posts by other members, I've come up with a condensed method of doing this reset. This method works EVERY time, even w/o a stopwatch. I've used this method successfully a dozen times, or so, now w/o a watch. After a few times, you won't need a watch or instructions. You'll get so darn good at it, you'll find yourself doing it while waiting at a traffic light.

Timing is not as critical with this method...no stop watch needed. Just count in your head...one-one thousand, two-one thousand, etc, or use stop watch. The most critical step is step #3....wait 10 sec, instead of 7.

1. Ignition "ON", count to 3.
2. Depress/Release pedal 5 times...hard and fast.
3. Count to 10 (not 7!) and fully depress pedal
4. Count to 12 (SES should be blinking), release pedal
5. Count to 10, depress pedal
6. Count to 10, release pedal.
7. Turn off ignition, then start engine. Done!

Accelerator Pedal Release Position Learning

Operation Procedure

1. Make sure that the accelerator pedal is fully released.
2. Turn ignition switch “ON” and wait at least 2 seconds.
3. Turn ignition switch “OFF” wait at least 10 seconds.
4. Turn ignition switch “ON” and wait at least 2 seconds.
5. Turn ignition switch “OFF” wait at least 10 seconds.

Throttle Valve Closed Position Learning

Operation Procedures

1. Make sure that accelerator pedal is fully released.
2. Turn ignition switch is “ON”.
3. Turn ignition switch is “OFF” wait at least 10 seconds.
Make sure that the throttle valve moves during above 10 seconds by confirming the operating sound.

Idle Air Volume Learning (Throttle Position Learning)

It is better to count the time accurately with a clock.

Operation Procedures

1. Perform “Accelerator Pedal Released Position Learning”.
2. Perform “Throttle Valve Closed Position Learning”.
3. Start engine and warm it up to normal operating temperature.
4. Turn ignition switch “OFF” and wait at least 10 seconds.
5. Conform that accelerator pedal is fully released, turn ignition switch “ON” and wait 3 seconds.
6. Repeat the following (steps 7a, 7b) procedures quickly five times within 5 seconds.
7a. Fully depress the accelerator pedal (HARD)
7b. Fully release the accelerator pedal.
8. Wait 7 seconds, fully depress the accelerator pedal and keep it for approx. 20 seconds until the Check Engine Light (CEL) stops blinking and turned ON.
9. Fully release the accelerator pedal within 3 seconds after the CEL is ON.
10. Start engine and let it idle.
11. Wait 20 seconds.
12. Rev up the engine two or three times and make sure the idle speed and ignition timing are within the specifications.

[HavockWK]

Thanks alot Rocky. I do have a question though. Do you know how resetting the ECU through the above method differs from disconnecting the battery for several hours? Is it just a faster way to do it?

[dbo1]

From what I've read, it's just that...a faster way to do what the ECU will eventually do on it's own. The ECU will gather external data for some period of time, and adjust the A/F ratio/timing accordingly. This is why many people believe that N/A bolt-ons won't do much in the long run. The ECU will compensate and retard the timing.

I've been a member at my350z for more than a year and read dozens of posts on these exact same issues/problems. It's kinda funny, I'm planning on selling my Z to get a Titan and looks like I'll be running into the same barriers.

[HavockWK]

Originally Posted by dbo1

From what I've read, it's just that...a faster way to do what the ECU will eventually do on it's own. The ECU will gather external data for some period of time, and adjust the A/F ratio/timing accordingly. This is why many people believe that N/A bolt-ons won't do much in the long run. The ECU will compensate and retard the timing.

I've been a member at my350z for more than a year and read dozens of posts on these exact same issues/problems. It's kinda funny, I'm planning on selling my Z to get a Titan and looks like I'll be running into the same barriers.

Thanks dbo. Welcome to TitanTalk and I hope you get a Titan soon!

I guess it makes sense that Nissan would put the same kind of technology in these two vehicles.

[tortuga]

excellent information Rocky!!! preciate!!!

[SmoKedOuTtiTan]

Nice! Something for me to do tomorrow.

[EPTITAN]

I just had to reset the ECU due to the CEL being on after I got my alarm installed. It took me a couple tries but it worked. Great info, I will have to give this a try, thanks!!!!

[life_is_good]

nice to know. i will have to try

[RockyMtnTitan]

Originally Posted by HavockWK

Thanks alot Rocky. I do have a question though. Do you know how resetting the ECU through the above method differs from disconnecting the battery for several hours? Is it just a faster way to do it?

It's just a faster, for sure method of resetting the ecu. There has been much discussion about how long it takes to clear the ram with the battery disconnected....2 hrs, 12, 24....there's no way to know for sure with that method. This way takes away the guess work.

[avroflyer]

Great suggestion, but for some reason I dont seem to be getting any success from the test. I printed off the instructions and tried it for 10 minutes and couldn't get the damn SES light to blink. Anybody have better luck?

[K-MU]

Would it be OK to just reset the ECU or is it recomended to do the whole thing (all the procedures)

I want to do it ASAP...

[RockyMtnTitan]

Originally Posted by K-MU

Would it be OK to just reset the ECU or is it recomended to do the whole thing (all the procedures)

I want to do it ASAP...

You could do just the ecu reset, if all you want to do is clear the ram after doing a performance mod, but I think the procedures do go hand in hand. I believe part of the relearning the ecu does after a reset is learning your driving habits, i.e., how fast you drop the accelerator, the distance the positioners travel, etc. So to me it seems important for the ecu to see the correct voltage values when the accelerator and throttle valve positioners are at their min/max extremes. An occasional recalibration sure can't hurt, and could help a great deal.

In my situation, I tried just the positioner relearning procedures a while back to see if it would cure the idle problem I mentioned....and it did. It didn't seem to change the performance much, if any. However when I came across the ecu reset procedure from Technosquare which recommended doing the reset, followed by all the other relearning procedures, I did it and the notice in low end power was very noticable. I don't fully understand why, because I've done the reset several times before using the battery disconn method after doing mods and never noticed an immediate improvement, which was expected as the ecu needs time to relearn the increased airflow seen. So why wiping the ecu memory clean and then doing the positioner relearning procedures netted me more low end torque, is a mystery to me.

This is how Technosquare does it, and they do know a little more about this ecu stuff than me, that's for sure! Like I mentioned, I think it's a good thing to do periodically, regardless of whether or not you see any performance gains from it. It can be a pain to get the timing down on it (esp the ecu reset and idle air learning) , but it's not too bad once you do it a few times.

[The_Man]

Thanks for the info, RockyMtnTitan.

Did you ever get those pretty new resos installed in place of your rear cats? I recall reading a while ago that you had trouble finding a shop to do it.

By the way, I was in your neck of the woods a couple of weeks ago (Conifer) and it snowed every friggin' day I was there. Depressing...

[RockyMtnTitan]

Originally Posted by The_Man

Thanks for the info, RockyMtnTitan.

Did you ever get those pretty new resos installed in place of your rear cats? I recall reading a while ago that you had trouble finding a shop to do it.

By the way, I was in your neck of the woods a couple of weeks ago (Conifer) and it snowed every friggin' day I was there. Depressing...

I finally found a guy that'll install them...just waitin' for him to call me to set it up after hours.

I was up at our mountain house above Alma in south park that same weekend and had a similar experience with the snow. I think Spring is finally here, though....been in the 70's lately.

[decypher44]

Thank you SOOOO much for the instructions on the ECU Reset. It took 4 tries, but I got it. I guess I just had a fluke SES light. Hasn't come back. Saved me a lot of time and headache from going to the dealer!