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ECU Clear/ Reset

Old 03-13-2008, 06:24 PM
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Go to Autozone, get the code read for free, see what it is, then fix it.
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Old 03-14-2008, 03:31 PM
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Ecu

I tried that they couldnt read it
And i dont want to pay the dealer 90 dollars
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Old 03-14-2008, 05:21 PM
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Alright.........I'm just trying to help. Don't take offense at this next question, but are you 100% sure it the CEL(check engine light)?
If so............then we will move to the next step. I can't believe Autozone couldn't read it, but I'll take your word for it. Let me know.
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Old 03-14-2008, 08:26 PM
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I Hink I found It

No man no problem, sorry if i sounded rude

I found a leak in the exhaust where the cat back delete pipes hooks up to the headers, i tried doing the bolts again and i also checked the copper oring gasket and its fine, but i cant get rid of that gap any i deas anyone
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Old 03-15-2008, 01:49 PM
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Ecu Clear

Well guys i went to a different autozone about 15 minutes away and they were able to read the code it was a P0037, something about low o2
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Old 03-15-2008, 07:21 PM
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Okay...that's the rear o2 sensor. There is a chance that the connector may be loose, but more than likely you will need to replace that sensor. You should go read these two threads, they aren't that long.

https://www.rx8club.com/showthread.p...ighlight=P0037

and

https://www.rx8club.com/showthread.p...ighlight=P0037


Dave
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Old 03-16-2008, 04:26 PM
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O2 sensor

Hey MAZUFER thanks for all your help it is not the sensor, i have a leak in front before the sensor, where the cat delete and the headers connect, and i need to find something to put on there to stop that

Any IDEAS anyone????

It is about a millimeter

Last edited by luke7575; 03-16-2008 at 11:34 PM. Reason: Sorry MAZURFER
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Old 04-03-2008, 07:41 AM
  #108  
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Originally Posted by turbine View Post
..............
Make sure to drive easy after your reset. Unlike all other car resets. If it were any other car you would want to run the **** out of it after reset.
......
why you have to drive easy after ECU reset and not the opposite ?
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Old 04-04-2008, 07:36 AM
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Well having in mind that you keep your 8 stock or current mods how often someone should reset the ECU in order to clear the LTFT? I know that those trims will be built again by the ECU but this time may be different.

So is there a rule of thump for resetting ? I know that if you feel your car sluggish you may think for an ECU reset but this sluggish may be only your feeling.

What do you usually do with reset? You never reset? Reset only if you mod your car and if you feel it performs poor? Any other condition ?
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Old 07-02-2008, 04:06 PM
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Red face help tech heads

sorry not to up with any of this can any of you tech heads help....... my 8 is acting up hard start sometimes and a flat spot in the lower rev's but fine when you get up speed would any of this reset help m'''''''''''':
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Old 07-04-2008, 08:01 PM
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Go have this done if it hasn't been!

http://www.finishlineperformance.com...14-08-1924.pdf
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Old 08-11-2008, 09:32 PM
  #112  
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interesting thread
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Old 08-15-2008, 08:44 PM
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Just wondering...if I went to the track for a high performance driving course (lapping), and the car PCM learns all those stuff.

But then I install a CAI and reset the PCM using the "Reset mileage-ON-20 brake tabs" method, will the PCM lose everything about what I did in the track?

That would be the suck....
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Old 08-20-2008, 10:40 PM
  #114  
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OK, OK This is a long and interesring thread, I can say that I learned a lot from it, but I have a question: If you are running catless or even with a high flow cat ( for sure you will have a cell soon ) now if you have that cell, will this cell compromise your engine performance??? yes or no.
can you get rid of it? how? is there a simulator that works?
thank you.
manny
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Old 08-21-2008, 02:17 PM
  #115  
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There are numerous methods to clear the CEL (read the pages leading up to this)...however clearing the CEL will accomplish nothing if the problem that is causing it is not fixed.

For example, if you got a CEL from a bad batch of gas, chances are you will keep popping the CEL until you run through that batch of gas. If you have a CEL from a leak in the exhaust or intake, then clearing the CEL accomplishes nothing.

The only thing clearing the CEL really accomplishes is seeing if the fix you did corrected the problem, or to see if the problem is 1-shot or re-occuring. And if the CEL is from a 1-time deal, not a reoccuring problem (like driving through a thick cloud of smoke might pop the CEL from bad air), if the car does not see that same problem within a few 'drive cycles' (think 1 cycle is driving to work, another cycle is driving home, etc...), then it will clear the CEL for you, writing it off as a freak occurance. How many cycles it takes for it to clear -most likely- depends on which error caused it, as some errors are more serious than others, and are justified in the system watching for another over a longer period of time.

Disconnecting the battery for a period of time allows the internal capacitors to run dry, and the computer to lose the ability to save variables, so when you reconnect the battery the variables are clear. This includes CELs, ECU fuel mapping, Radio Presets, and stability control calculations, among other things.

This does not include the latest firmware 'Flash'.

The amount of time needed for a complete drain of power from the capacitors can vary from vehicle to vehicle. I generally get success on my 8 from 30-60 seconds. My Protege5 required more like 3 minutes. Pumping the brake with the battery off likely just forces an increased drain on the capacitors, clearing the variables faster. With no power running through the car, I can't see it 'seeing' the brake push as a 'sequence' to take an action, much less having the power to take the action of clearing information.

If you do a complete clear by removing the battery connection, your car still has to rebuild several variables, including the fuel trim mapping as well as the stability control mapping. Since the stability control mapping is not 'complete', your DSC and TC lights will remain lit until they are complete. The systems simply don't have enough information to act on correctly if it is needed, so those systems are disabled until they do. Turning the wheel to it's stops in each direction generally gives the stability control system enough information to work on, and the lights will go off.

I am not sold on 'drive easy' or 'drive hard' after an ECU reset for re-doing the fuel mapping. Theoretically, driving it easy initially should improve gas mileage, but negatively impact maximum performance, and driving it hard should improve performance and negatively impact gas mileage. I don't see how driving easy during an ECU re-mapping of the fuel trim would improve performance, but perhaps it is something unique to rotorys I am not familiar with.

Sidenote:
Reseting the EUC before warmup track run would -probably- improve on track performance after a while, and reseting the ECU and driving easy before a long trip would -probably- improve overall gas mileage. I will have to test this.

So if you are just looking to clear a CEL, then try the other methods first. But if you decide to go the complete reset route, keep in mind that your car's performance, behavior, and responsiveness may change... and not necessarily better or worse.

Last edited by RIWWP; 08-21-2008 at 02:21 PM.
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Old 10-18-2008, 01:32 PM
  #116  
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Thanks Everyone!

This forum is the best. I have a 2007 Rx8 with only 7700 miles and the CEL came on yesterday as soon as I turned it on. I was just sick about it. Made a very inconvenient appointment with the dealer and in the meantime read a bit on here.

I checked the gas cap, felt a little lose but the CEL did not go away. After reading the reset procedures on here, I decided to give it a try. I reset the NVRAM and KAM but the CEL was still on. So I disconnected the battery (negative only) turned back on and light was gone! So I decided to do one more reset of the KAM and NVRAM and now I will see. If the light comes back, then I know I have something wrong for sure. Thanks again everybody!!!!
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Old 11-20-2008, 06:37 PM
  #117  
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Originally Posted by Charles R. Hill View Post
Like I said, I don't know if this procedure helps or not but I did it anyway. After two days with no cat my CEL just shut off. The latest issue of "Import Tuner" did some parts swaps and dyno pulls and I can say that my engine has the exact same peaks and valleys in the power curve that they measured. Must be that "N" flash. I'm beginning to hate it.

Assuming there are no idle speed or initial timing issues;

1) Start the engine and warm it up completely. This means allowing one full cooling fan cycle. During warm up, make sure all accessories are turned off.

2) Idle the engine for more than 30s after the cooling fan has stopped, then turn the engine off.

3) Re-start the engine and drive the car in the following fashion:
A) Idle the engine in neutral for more than 7m35s.
B) Drive in first or second gears, between 25-46 mph, for more than 30s.
C) Drive in second or third gears, between 38-62 mph, for more than 20s.
D) Drive in fourth or fifth gears, between 32-62 mph, for more than 2m.

It is said in the Mazda repair manual that this procedure allows the PCM to measure all that it needs to ensure no further CEL's unless there is an outstanding issue.

CRH
Has anyone ever confirmed whether this procedure helps or not?
Or if it needs to be tweaked or refined?

(Had a CEL 0456 - Evap - on Sunday. Followed the procedure of disconnecting the battery
and pressing down on the brake last weekend, the CEL went away, but I lost my trims
and the car wanted to stall. The CEL came back on today, so I replaced the gas cap,
and I want to disconnect the battery again to clear the CEL, but I want to get
trims back faster without the danger of stalling.)

So has this procedure been successful?
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Old 12-27-2008, 07:21 PM
  #118  
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hey hows it going
i know this migth b out of the subject
but
does anyone know what kind of scanner i can use on my rx8???
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Old 12-27-2008, 07:25 PM
  #119  
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Bought this one the other day...works well on my laptop with Bluetooth..

http://www.obdkey.com/obd_bluetooth_info.asp

Or, you can get it with USB Cabe...
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Old 12-28-2008, 06:27 AM
  #120  
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There are many, do some searches.
It needs to be CAN bus compatible.
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Old 03-19-2009, 03:16 PM
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I've seen numerous posts where it's been recommended to pull the room fuse to reset the ECU. How does this differ from the processes listed in this thread?

thanks,
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Old 03-19-2009, 03:49 PM
  #122  
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The room fuse powers (among other things) the ECU when the ignition is off.

Pulling it removes the KAM from the computer so, yeah, it is the same as pulling the battery cable.


The difference from the two processes to clear the ECU is that the 'approved processes are from the Mazda Factory Service Manual, and don't require re-setting the radio stations.....

The two FSM processes also clear different parts of the PCM (the odometer reset for the NVRAM; and the Brake-stomp for the KAM).

Hope this answers your question.


EDIT: I stand corrected. See teknics' post following. Thanks!

Last edited by Silver06; 03-19-2009 at 04:39 PM.
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Old 03-19-2009, 04:37 PM
  #123  
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https://www.rx8club.com/showthread.p...45#post2923345

The Odometer button has NOTHING to do with PCM Memory.

If it's in the FSM please tell me the page number so i can inform mazda and it can be properly addressed as i have yet to find it in our version.

kevin.

Last edited by teknics; 03-19-2009 at 04:39 PM.
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Old 10-16-2009, 07:31 PM
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after i reset the NVRAM my 8 will no longer idle, it turns on goes up to about 1,000 rpm then drops to 0 almost instantly any idea what is going on?
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Old 10-24-2009, 01:17 AM
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I'm not asking any questions, just providing advice. So I don't know if this was mentioned earlier since I didn't read all the posts, but, if you have the Nav system, there are 3 different secret menus that can be accessed which will allow you to view the recorded data in various parts of your car's computer systems including GPS, ECU, sensors, etc., and via these menus, you have the ability to delete some of these records.
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