COMPORT Troubleshooting: Write ECU Failure

If you have a situation where your COMPORT fails to write your tune, no need to worry. This can happen for a few reasons.

Simple Correctable Reasons:

  1. Key is NOT in the ON position – Check that you have your ignition turned fully into the ON position 
    • For push-to-start ignition -press start button TWICE
    • For vehicles using key-style ignition, TWO key clicks.
  2. The COMPORT cable is NOT fully seated into the OBD2 port – Double check your diagnostic cable connection at both the COMPORT and your vehicle‘s OBD2 connector
  3. Ensure BATTERY VOLTAGE is good/healthy – Connect a battery charger when possible. Older vehicles with a weaker charged battery or OEM battery can cause voltage drop during programming. Most vehicles will require a 12.5-13.5 volts in order to program the ECU.
  4. Some cases, from those using a “piggy back” prior to using the COMPORT. IF the problem persist, disconnect the battery and let the vehicle sit for about 30min-1hr. This will ensure that everything has powered down. Once this time has passed, connect the battery and start the car. Have the vehicle run for about 10min(s) then turn the vehicle off and attempt to WRITE the tune again.
  5. *** Note: IF an error occurs during programming, DO NOT turn off the key or unplug the COMPORT. This is a simple fix. Go back to the “TUNING” menu and start the programming process again by selecting “WRITE” and the tune you wanted to use. The COMPORT will pick up were it had left off.

COMPORT Un-correctable Reasons:

  1. Your vehicle’s ECU has been locked by another tuning tool.
    • This issue will result in a COMPORT ERROR CODE 10003

Other tools often change the seed-key in the ECU (from OEM), making it impossible for the COMPORT to understand the correct way to read the factory/modified data from the ECU. In this case, you must have your ECU flashed back to OEM using the COMPORT, original tuner that previously tuned the vehicle or you can go to the dealer to have the vehicle programmed back to stock.

  • We can recover SOME ECU’s, returning them back to stock. There is a small fee for this service. Please contact us for more details.

COMPORT ERROR CODE 10001 and 10002: 

This error is due to the COMPORT being out of date or missing UPDATED information. Please use COMPORT MANAGER to update your COMPORT. Once completed updating, go to your vehicle and try to READ your ECU again. If the problem persists, contact us for further assistance.