Reflash - Upgrade FAQ


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Hondata, Inc.
2840 Columbia St
Torrance, CA 90503

How do you get your ECU reflashed?

  • Fill out this form
  • Contact your dealer. All sales are made through Hondata dealers. Do not call Hondata.
  • Your dealer or you will need to remove and send your ECU, immobilizer and key to Hondata.

The K series Honda ECU is flash programmable. The ECU can be repeatedly reprogrammed without removing any chips. But, these ECUs must have a working immobilizer system before they can be programmed. You, or a Hondata dealer will need to remove your ECU and immobilizer and send with an ignition key to Hondata to be reprogrammed. 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.

Why can't Hondata just send an ECU

The ignition key has a serial number. The ECU and Immobilizer are programmed with the same serial number from the factory. If the serial numbers do not match the car will get no fuel or spark. Therefore if we sent a new ECU your car would not start, and you would have to have it towed to an Acura/Honda dealership for reprogramming the immobilizer. This would also double the price of the Hondata upgrade.

Can I just take it to a Hondata dealer to get reprogrammed and not send it to Hondata?

Regardless of where you take the ECU it will need to be sent to Hondata. Hondata has the only programmer for the K series ECUs.

Will this affect the fuel economy?

No. With the extra low end torque you will find can use one gear higher than you normally would. This may improve your economy. If you drive the car harder then fuel economy will suffer. To check your economy measure it over 2-3 consecutive refills - not just one. Fill up at the same pump every time.

Will this affect the engine life?

The engine operates more efficiently with the Hondata program. Honda engines are built well. In 1997 Hondata ran a circuit race car with a stock 1989 B16a engine with a raised 8600 rpm redline. This engine logged 24 hours circuit time hitting the redline every 3-4 seconds. The engine was then stripped down and measured. Everything was within new specification. The K series engine is 10 years newer and is built a lot better. 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.

How did we do it?

The K series engines add another dimension to Honda tuning: iVTEC or to be specific an intake cam that can be varied by as much as 25 degrees on the fly. The main changes were advancing the ignition, leaning the fuel a little and tuning for higher octane.

What do others think?

Feedback is very positive. This modification makes the car very smooth to drive. Read some customer feedback and see also a review on Temple of VTEC. We have two reports back of 0-60 times being lowered by half a second. Two others running just a CAI, ECU upgrade and test pipe are running 14.1 and 14.2 seconds for the 1/4 mile.

Can an Acura dealer erase this program?

Only if another update is released could an Acura 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).

Why did Honda not do this to start off with?

There could be several reasons. We suspect the most important reason is emissions. The K20 series engine is LEV ( low emissions vehicle); a standard which is difficult to achieve. The second may be a safety margin Honda has programmed for poor quality / low octane fuels. Another reason may be marketing. Honda may want to introduce a more powerful model at a later time.

What about bolt ons?

The programs have been tested to work well with a variety of intakes and exhausts. No retuning is necessary after an intake is added.

If you currently run nitrous, these programs will probably not be suitable due to the aggressive 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?

Hondata has tested with a prototype supercharged K20 engine in which fuel was supplied via additional electronics. The results were positive. Considerably more R&D will be needed for Hondata to calibrate the ECU for larger injectors and boost up to the stock MAP sensor limit of 11.3 lb (1.8 bar) without using additional electronics.

What octane is recommended.

91 octane fuel or better must be used for the Type-S engine, and is recommended for other K-Series engines. Most of the gains seen on the base model RSX were made on 87 octane. The last few hp were made switching to 91 octane. If you anticipate traveling somewhere there is poor quality low octane fuel, purchase octane booster.


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