ECU Clear/ Reset
#1
ECU Clear/ Reset
I just wanted to pass on that the ECU appears to be cleared out using the same technique as in the 3rd gen RX-7.
Remove the battery ground, wait for a few minutes, and press the brake for a few seconds.
Not sure if it is worth any value, but I thought I would put it out there in an easy to search format.
Remove the battery ground, wait for a few minutes, and press the brake for a few seconds.
Not sure if it is worth any value, but I thought I would put it out there in an easy to search format.
#3
That won't clear the KAM and can do some other funky things if it isn't complete. It will also erase your radio presets and clock settings.
There are two reset procedures, one for the NVRAM and the other for the KAM. Neither will erase your radio presets and such like the method SpooledUp7 posted:
1) With the key in the off position, press and hold the odometer reset button and turn the key to on;
Continue to hold the odo button until the odometer reads "TEST" and then release.
2) Turn the key to off and repeat step one.
This will reset the entire PCM except the KAM which contains the sensor profiles amongst other things. You can reset it with the familiar procedure:
1) Turn the key to on
2) Depress the brake pedal rapidly 20 times in a row until the oil pressure gauge sweeps to halfway and back again.
There are two reset procedures, one for the NVRAM and the other for the KAM. Neither will erase your radio presets and such like the method SpooledUp7 posted:
1) With the key in the off position, press and hold the odometer reset button and turn the key to on;
Continue to hold the odo button until the odometer reads "TEST" and then release.
2) Turn the key to off and repeat step one.
This will reset the entire PCM except the KAM which contains the sensor profiles amongst other things. You can reset it with the familiar procedure:
1) Turn the key to on
2) Depress the brake pedal rapidly 20 times in a row until the oil pressure gauge sweeps to halfway and back again.
The following 2 users liked this post by MazdaManiac:
James Robinson (04-10-2020),
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#5
Originally posted by Booster MPS
Sorry for the dumb question but what are the NVRAM and KAM and what do the acronyms stand for?
Sorry for the dumb question but what are the NVRAM and KAM and what do the acronyms stand for?
Don't know what KAM stands for...
#7
Why would you want to reset the NVRAM or KAM? I guess I unknowingly reset my KAM when I checked for the M flash last week. I have even read some posts here that claim temporary performance increases after resetting the KAM.
#11
Are you saying that clearing the NVRAM and KAM simply resets the PCM to factory defaults and clears any stored DTCs? What (if any) other effect does this have on the PCM, and will there be any ill effects as a result?
The reason I ask is that I recently had my 8 in for the airbag recall, and the M flash. I verified the flash with the brake pedal test, (which apparently also reset the KAM) immediately when I started the car when I picked it up. It has run fine since, with one exception. When warm, and at idle, the engine will periodically suddenly sputter from 950rpm (normal idle speed) to around 4-500 rpm, almost as if it is dying. It will then catch itself and idle back up to normal. Not a big problem, but this never occurred prior to the flash, and is a little spooky when sitting at a red light!
Do you think resetting the NVRAM and/or KAM and following the MODE 1 and MODE 3 instuctions outllined in step 12 in the new "Engine Cranks/No Start" TSB might cure this?
http://www.finishlineperformance.com...1-04-1273d.pdf
Thanks
The reason I ask is that I recently had my 8 in for the airbag recall, and the M flash. I verified the flash with the brake pedal test, (which apparently also reset the KAM) immediately when I started the car when I picked it up. It has run fine since, with one exception. When warm, and at idle, the engine will periodically suddenly sputter from 950rpm (normal idle speed) to around 4-500 rpm, almost as if it is dying. It will then catch itself and idle back up to normal. Not a big problem, but this never occurred prior to the flash, and is a little spooky when sitting at a red light!
Do you think resetting the NVRAM and/or KAM and following the MODE 1 and MODE 3 instuctions outllined in step 12 in the new "Engine Cranks/No Start" TSB might cure this?
http://www.finishlineperformance.com...1-04-1273d.pdf
Thanks
#12
I'm kinda wondering about my own PCM as I have had all sorts of trouble since I got mine flashed to the N level. The car runs great, and smooth, except when I go to WOT at which point it seems to make a strange rumbling/growling kinda sound on the intake side(which it never used to do) when I hit 7K in first gear, 5.5K in second, and 5K in the other gears.
With nitrous use the same problem occurs but at slightlty lower rpm's. I am wondering if the engine's ignition curve is set slightly too far advanced(?).
I have checked all of my sensors and even removed the intake manifold to check for cracks. Everything looks good, mechanically and electrically.
I have also performed the NVRAM/KAM clearing procedures provided by MM.
Any ideas?
CRH
With nitrous use the same problem occurs but at slightlty lower rpm's. I am wondering if the engine's ignition curve is set slightly too far advanced(?).
I have checked all of my sensors and even removed the intake manifold to check for cracks. Everything looks good, mechanically and electrically.
I have also performed the NVRAM/KAM clearing procedures provided by MM.
Any ideas?
CRH
#15
Originally Posted by MazdaManiac
There are two reset procedures, one for the NVRAM and the other for the KAM.
1) With the key in the off position, press and hold the odometer reset button and turn the key to on;
Continue to hold the odo button until the odometer reads "TEST" and then release.
1) With the key in the off position, press and hold the odometer reset button and turn the key to on;
Continue to hold the odo button until the odometer reads "TEST" and then release.
I did notice that while in the "test" mode,
if I continued to press & release the odom button
it scanned through several different settings.
Any of these settings worth "monkeying with?"
EBF
#16
I did the same, most seem to be instrument gauge and light checks, they will sweep through their range and hold a setting for a period of time or light up various dash indicator lights, I couldn't figure out what several of the tests did though, there was nothing apparent
#18
Other than just driving the car around after clearing the PCM, there is a definite "after repair" procedure that allows the PCM to gather the necessary data to check for further CEL's/MIL's. I did this step-by-step process but I am not sure if there was any benefit. Anyone else interested in trying it and see if it helps? If so, I'll put up the step-by-step.
CRH
CRH
The following users liked this post:
JoeyKillinEm951 (02-21-2021)
#24
I tried those things out and it didn't help the power problem, it did raise the cold idle. Then to get my mind off thins I put a shifter in it. That helped, the 2-3 shift alone was worth the price. Hey wait.............it didn't cost me anything.
#25
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
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