Troubleshooting: Writing ECU Data

The most common reasons that your may have issues writing your tune file can be found below:

"The Read and Write Button are both greyed out." - If you've just installed your OFT for the first time, there is a chance that the OFT did not auto-generate your compatible tune files. Please read more about why this happens in the 'Auto-Generating Tune Files' section of this users guide.

• The READ button on your OFT may both be greyed because your tablet has already read, and saved your ORIGINAL program from your ECU to its internal memory slot. 
• The WRITE button may be greyed because the tablet could not auto-generate stage tune files for you, and there is simply nothing available to flash.

The next step is to manually locate, and upload the tune files to your OFT. Then the WRITE button will be available. Please see the article "Where do I find my compatible tune files?" in this section of the OFT user guide.

Easily correctable:

1. Key is NOT in the ON position - Check that you have your ignition turned ON 
   • Generally, your fuel gauge should be indicating a level if the key is in the right position
   • For push-to-start systems - usually TWO button presses.
   • For conventional key ignitions, TWO key clicks.
   • For bikes, one Key click to ON.
2. The OFT cable is not fully seated - Double check your diagnostic cable connection at both the OFT, and your vehicle
3. Ensure battery voltage is good/healthy - Connect a battery charger when possible

Not so easy to correct:

1. Your vehicle's ECU has been locked by another tuning tool AFTER initially programming with your OFT. 
   • Common tools are BRZEdit, MazdaEdit, ECUTek -- but be aware there are many many more tools available beyond the three mentioned here.
   • Generally this issue will result in an OFTCODE 10003

Other tools often change the seed-key in the ECU (from OEM), making it impossible for the OFT to understand the correct way to write the tune data to the ECU. In these cases, you must have your ECU flashed back to OEM using the tool that previously wrote the tune file. 

• We can recover some ECU's, returning them back to stock for a small fee. Please contact us via the contact form on our site for more details.

Because the security info for the ECU may have been changed after this mishap, the OFT may no longer agree to write the ECU, and would need to be traded in for credit toward a new OFT. Please complete our online RMA form to get this process started.

OFTCODE 10001 and 10002: 

This error is due to the protocol file on your OFT being out of date, or missing for some reason. Please use OFM to update your OFT, and then try to write your ECU again. If the problem persists, use the contact form on our website to request assistance.