How can I reset my RX-8's ECU?

The easy way is to disconnect your car battery and stomp on the brake peddle a few times. Then leave it for a few minutes.

The problem with this method is that some profiles are stored in RAM that cannot be cleared by disconnecting the battery.

Each of the reset methods described here serve a different purpose:


Clearing the eccentric shaft plate profile (AKA brake stomp reset):

1. Turn ignition switch to �ON� position, but do not start engine.

2. Pump the brake pedal at least 20 times within 8 seconds after the ignition switch is turned ON.

What it does:

The RX8 is equipped with a unique system that memorizes the tooth pattern or �profile� of the eccentric shaft position plate. The eccentric shaft plate profile is stored in an area of the PCM with non-volatile RAM (NVRAM) which cannot be cleared by disconnecting the vehicle�s battery, or clearing keep alive memory (KAM). If the eccentric shaft plate profile is not cleared after certain repairs, MIL illumination and misfire DTCs may occur.


What it really does: Reset profiles stored in NVRAM


KAM reset (AKA test reset)

1. Press and hold the odometer reset button.
2. While pressing the odometer reset button, turn ignition switch to �ON� position, but do not start engine.
3. You will now see "TEST" written in the odometer area of your dash.
4. Let go of the reset button, then then the ignition switch to "OFF"
5. Repeat steps 1-4 an additional time.

What this does: Reset everything besides NVRAM profiles.



Neither of these reset procedures will remove your radio presets. However the battery disconnect will.

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User Comments


i took the fuses out inside the car,long story. the abs light and traction control light is now on. never had problems with the car,great car. any info on how to reset these would help. oh and the dealership 'just to look at your car' would cost me $120.00 bucks.anything to make a buck.

Dietrich on October 6th, 2009

its happn same with me could not find any thing for my 8

sunny on July 2nd, 2010

hi guys dont know if your still having some problems doubt it since it was so long ago. but for anyone else that reads this after disconnecting the battery or fuses the car needs to re calibrate its abs and traction control it does this while driving so all you have to do is drive it For a few miles. you will not have abs or traction control so be carefull till the car turns the lights off

Greg on August 16th, 2010

Thanks Greg i appreciate that

Chris on September 20th, 2010

I had a new battery fitted in my Rx 8 today. I drove away from the Garage and when I tried to brake at slow speed there were large shudders from the rear. I reversed into the parking lot and asked the mechanics to check it out. Of course they drove it around and nothing happened . It must have been the ABS recalibrating as you point out above, but I had no ABS warning lights on...thank you

Paul on November 22nd, 2010

abs and traction light should go off after 6 drive cycles ...which is need for recalibration

trini on February 4th, 2011

THE TRACTION LIGHT WITH THE ABS IS EASY TO RESET PUT THE SWITCH IN ON POSITION AND TURN YOUR STEERING WHEEL ALL THE WAY TO THE LEFT AND THEN ALL THE WAY TO THE RIGHT

FERNANDO on May 23rd, 2011

ALL THE LIGHTS ON MY DASH IS ON THEY SAY ITS MY ECU.HOW WOULD I KNOW

JACQUES on June 7th, 2011

for the traction light trn the car off while driving and start it back up holding the clutch in it worked for me twice now

aaron on June 14th, 2011

I love my rx8 its my baby

Ray on July 20th, 2011

Have rx8 that mazda just replaced motor now the coolant and check engine light comes on.The check engine light stays on all the time,but the coolant light does not. any ideas tryin not ta take it back to mazda

chris on July 31st, 2011

Out RX* has been down in shop for two weeks. They replace plugs and wires, but it has some problem with the injecction system. Car won't run. Does anybody have any ideas? Mike

Mikerun. on August 19th, 2011

We have a '04 RX8,,new 2 us n we love it :) however last nite we noticed our brake lights r not working!!checked the fuse-its fine.....any1 have any ideas??thanx....

tiffany on September 11th, 2011

Pump the brake 20 times in no more than *seconds and the ECU resets with ignition on!

Grant on December 7th, 2011

My engine light came on as my interior lighting, AC, keyless entry and audio system shut off. The dash, exterior lights and power windows are still functional. I took the car to a Mazda dealership and they were as baffled as I am, not comforting at all. I am so looking forward to seeing the bill for this mess. Anyone has a clue what lead to this?

Delb on December 27th, 2011

hi guys, i have a similar problem with my rx8, i disconnected my battery and i purchased a new one but now the car wont start .. ive heard from many people that my engine dis-programed due to some type of security , how can i possibly reset my car and allow it to run again?...... when i attempt to start the car... the engine makes a type of struggling whistling noise and fails to start... please help

arley on January 24th, 2012

I got a 04 grand touring 8 with 87k on it I have been trying and trying to find a way to turn my TC off but no matter how long I hold it down the light won't come on showing it is off really wondering what is going on, I'm not a car dummy but my car has me fooled on this, any ideas on what I can do?

Phe on April 8th, 2012

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