How to Reset your ECU on your CX-7

[Raider]

Thanks go to Mikomi for this information. He is a nice guy, for a coffee-addicted, flooded river driving, pothole hitting, Panamanian.

Why do an ECU reset?
Whenever you do any modification to the car that involves the intake, engine, or exhaust, it is highly recommended that you reset the ECU. With the ECU back to blank slate, it will give it the opportunity to learn everything all over again, including whatever effects the new mod will introduce. And thus everything will hopefully function in perfect harmony happily ever after.


Side Effects of an ECU reset
There are several things that will happen to the car with a reset, so this is a little heads up. Side effects include and I think is limited to these.

* Lose all radio presets
* Clock needs to be reset
* Windows stop working
* TCS and DSC don't work (they will reactivate on their own if you just drive off without doing the routine to reset the TCS and DSC)


What will NOT happen with an ECU reset
Any ECU programming/flashes done by Mazda/Dealer won't be lost/erased. Only the new stuff the ECU learn on its own is lost. But the basic programming remains intact.


How to reset your ECU

1. Disconnect the negative terminal on the car battery
2. Pump the brake pedal several times (7-8 times) to discharge any left over current (or alternatively you can wait a few hours, your pick)
3. Reconnect battery
4. Congratulations, you have just reset the ECU, but now you have to reset a few other things



How to recover from an ECU reset

* For the windows
1. Just push the switch down until it clicks (moderator edit: hold the switch in the 1st detent, not the auto 2nd detent)
2. Then raise the window until it clicks
3. Do this for driver and passenger side windows.
o 2008+ models, 2007 models with TSB done: you can use the buttons on the driver side to reset the left and right windows
o 2007 models: using the button at each door, do the reset. The reset of the passenger side window will not work with the driver side button.
* For the TCS land DSC lights
1. Start the vehicle
2. Turn steering wheel all the way to the right
3. Turn steering wheel all the way to the left
4. Turn off ignition
5. Start the vehicle
6. TCS and DSC are now reset

[mps3]

Would you also know how to turn off the TCS (skid light) light on a Mazdaspeed 3?

[mikomi]

You cantry the CX-7 method, chances are it'll work for the Speed3s. But you should go to the Speed3 section of the forums to know for sure.

[Scynfewl]

Originally Posted by Raider Thanks go to Mikomi for this information. He is a nice guy, for a coffee-addicted, flooded river driving, pothole hitting, Panamanian. Why do an ECU reset? Whenever you do any modification to the car that involves the intake, engine, or exhaust, it is highly recommended that you reset the ECU. With the ECU back to blank slate, it will give it the opportunity to learn everything all over again, including whatever effects the new mod will introduce. And thus everything will hopefully function in perfect harmony happily ever after. Side Effects of an ECU reset There are several things that will happen to the car with a reset, so this is a little heads up. Side effects include and I think is limited to these. * Lose all radio presets * Clock needs to be reset * Windows stop working * TCS and DSC don't work (they will reactivate on their own if you just drive off without doing the routine to reset the TCS and DSC) What will NOT happen with an ECU reset Any ECU programming/flashes done by Mazda/Dealer won't be lost/erased. Only the new stuff the ECU learn on its own is lost. But the basic programming remains intact. How to reset your ECU 1. Disconnect the negative terminal on the car battery 2. Pump the brake pedal several times (7-8 times) to discharge any left over current (or alternatively you can wait a few hours, your pick) 3. Reconnect battery 4. Congratulations, you have just reset the ECU, but now you have to reset a few other things How to recover from an ECU reset * For the windows 1. Just push the switch down until it clicks (moderator edit: hold the switch in the 1st detent, not the auto 2nd detent) 2. Then raise the window until it clicks 3. Do this for driver and passenger side windows. o 2008+ models, 2007 models with TSB done: you can use the buttons on the driver side to reset the left and right windows o 2007 models: using the button at each door, do the reset. The reset of the passenger side window will not work with the driver side button. * For the TCS land DSC lights 1. Start the vehicle 2. Turn steering wheel all the way to the right 3. Turn steering wheel all the way to the left 4. Turn off ignition 5. Start the vehicle 6. TCS and DSC are now reset

For this... I donate.

[dgillie]

so thats how you get the windows to work again. i did an ecu reset the other day. and mine eventually started working again. nice to know there is a faster way. I reset mine to install a battery kill switch in the engine bay. so in the future when i plan to upgrade stereo and other electronics it takes me 5 seconds to disconnect it.

[RabbitSpeed]

So, I had to replace the master window switch on my wife's 2011 CX-7. I got it all in connected the battery back. Well I forgot to secure the door latch/lock assembly, and w/o disconnecting the battery I put it back in place. Just after that the car made an audible as if I had the keys in the ignition. Now, the car won't start at all. I am pretty sure I have triggered the engine immobilizer... I've reset the ECM, but to no avail. The dash lights just come on and there's something humming under the hood (fuel pump possibly..) I can start it by disconnecting the ground and connecting it back with the key in the start position, but to just it off I have to disconnect the fuel pump. I really really don't want to hang my head and go to the dealership.... Any tips or tricks to reset the security gremlins would be helpful.

[Zippinger]

Help! I took the battery out of my car. I put it back, all connections are tight. Keyless start wouldn't work, used key. Turned it on and some of the lights on the dash were flashing. The drivers side window rolled down but no auto function. Passenger side wouldn't work at all. Turned the car off and tried to turn it back on and now it won't start 2008 Mazda CX-7