• Reflash - Civic Si 2012-2015

Reflash your 2012-2015 Civic Si or ILX engine computer.

  • Fuel, ignition and cam timing optimized.
  • VTEC point unchanged
  • Rev limiter raised to 7600 rpm
  • Speed limiter removed
  • 10-15 top end hp gain depending on the dyno and modifications
  • 5-12 ft lb top end torque
  • Improved throttle response
  • California emissions legal (CARB EO D-742)

This is for an ECU reflash - the ECU is not included. Hondata does not sell direct - the reflash must be purchased from a Hondata dealer. The ECU reflash form must be sent with your ECU.



Sales Region US
Model Civic
Year 2012-2015
Market US
Trim Si
Engine K24
Transmission MT
Code K24Z7
Part Number 37820-RX0-A03 to 37820-RX0-A12

Does this fix 'rev hang'?

'Rev hang' is where the engine speed continues to rise even after the throttle is released while shifting. It also can be felt while driving slowly, where the vehicle surges forward after the throttle is released. The reflash reduces the 'rev hang' effect to a minimum.

Does the reflash work well at altitude

The additional power from the reflash is generated by modifying the fuel, ignition and cam angles. There are 10 tuning air pressure positions from sea level to vacuum. Hondata tunes at sea level.

As you rise in altitude, the air pressure reduces. This does not affect the fuel and cam angle changes, but it does affect the ignition changes . At around 8000 feet altitude there is no difference between the ignition timing for a stock and a reflashed ECU. At around 3700 feet, the ignition changes are a around half that of sea level.

Altitude changes do not affect the improvement Hondata has made to rev hang.

What if you have modifications?

This program was not tuned specifically for an intake. Any correctly designed intake or exhaust modification should work well with this reflash.

Will this affect my warranty?

Any increase in RPM limit is at your own risk. If you suffer engine damage that is related to excessive revs Honda / Acura will not cover your warranty.

With regard to aftermarket parts, the law is that warranty coverage cannot be denied simply because such parts are present on the vehicle, or have been used. For more details read the K series FAQ.

Some 2002 onwards and all 2006 onwards ECUs are flash programmable. The ECU can be repeatedly reprogrammed without removing or replacing and internal components.

How do you get your ECU reflashed?

  • Fill out this form
  • Contact your dealer. All sales are made through Hondata dealers.
  • Your dealer or you will need to remove and send your ECU, immobilizer and key to Hondata.

Do I need to send the key & immobilizer?

Only for 2002-2006 RSX and 2002-2005 Civic Si reflashes. All other reflashes do not need to send a key or immobilizer. Flashing the ECU does not in any way alter the immobilizer operation.

How long does it take?

The ECU will be reprogrammed and shipped out the same day it is received. Shipping in the continental USA is FEDEX next day.

Will this affect the fuel economy?

Assuming you drive the vehicle in the same way, no. Fueling at cruise is the same as stock.

Will this affect the engine life?

Provided your engine is maintained correctly this modification should not affect the engine's life.

Will this affect the warranty?

It should not.

Federal law sets forth requirements for warranties and contains a number of provisions to prevent vehicle manufacturers, dealers and others from unjustly denying warranty coverage. With regard to aftermarket parts, the gist of the law is that warranty coverage cannot be denied simply because such parts are present on the vehicle, or have been used. (see Federal Warranty Laws for details). The warranty coverage can be denied only if the aftermarket part caused the malfunction or damage for which warranty coverage is sought.

If a dealership denies warranty coverage (more details here) , they should be willing to do so in writing. Have the dealer describe the failure which is causing your problem AND how the dealer believes the aftermarket product installed is responsible for the problem. Keep an accurate log of all contacts and correspondence in addressing the warranty denial. Hondata will provide any technical information the dealership requires.

With any increase in rev limit there is an increased risk of valve damage. To minimize your risk use the Hondata program with the stock rev limit. All reports of valve damage we have heard have been as a result of miss-shift. The Type S valve springs are good. We have tested a Type S with an 8900 rev limit in a press test vehicle for several months with no problems.

Will any settings be lost?

Your ECU will lose some idle settings and fuel trim when it is unplugged. It will relearn idle automatically if you leave it idling for 10 minutes. As you drive the car it will relearn fuel trim values in a matter of minutes.

Can a Honda/Acura dealer erase this program?

Only if another Honda/Acura update is released could a dealer erase your existing program. If Honda/Acura comes out with an upgrade you are not obliged to have it installed. If you do not wish to have the dealer program installed there is a wire you can disconnect or cut, to prevent reprogramming. The charge for restoring an erased program is $75 (cashiers check or money order) shipping included.  You can also remove pin 7 from the OBD2 port to keep the dealer from reflashing your ecu (DO NOT CUT THIS WIRE).

What about bolt ons?

Most programs have been tested to work well with a variety of intakes and exhausts. No retuning is necessary after an intake is added.  Some programs as tuned specifically for an intake or exhaust, and if so, will mention this in the reflash notes.

If you currently run nitrous, these programs will probably not be suitable due to the ignition advance used. If you want to use nitrous and this program now, you must install a nitrous system that retards ignition.

What about turbo-charging and super-charging?

Use the K-Pro or FlashPro.

What octane is recommended?

For high compression engines (K20A2, K20Z1, K20Z3, K24Z7) 91 octane fuel or better is recommended.  For all other engines there are gains from using higher octant fuel, as the ECU will automatically advance the ignition timing if no knock is detected.

Reflash - Civic Si 2012-2015

  • Brand: Hondata, Inc.
  • Product Code: Reflash - Civic Si 2012-2015
  • Availability: In Stock
  • $295.00