Troubleshooting Accessport Communication and Flashing Errors

Can't Comm Verify the Ignition is On death

Have you ever been stuck on a screen with error messages like these when trying to install your Accessport or change maps?

There is a long list of potential reasons why an Accessport may have trouble communicating with a car’s ECU when attempting to complete a flash. A few of those are sometimes related to a problem with the Accessport, but the vast majority of the time the issue lies somewhere between the Accessport and the ECU. So, let’s run through a list of the most common problems and how to resolve them.

Stop and think:

Before you even start troubleshooting, consider the points below. This information will make the troubleshooting process much easier.

  1. If you purchased a used Accessport, check to be 100% sure it is not still Married/Installed to another car. On the Accessport go to:  “Help”  –  “About Accessport”  –  “Installation Status”
  2. Has your car ever been tuned by something other than an Accessport? If you aren’t certain, try to contact the previous owner to find out.
  3. Make a mental note of the last time the car was serviced by a shop or dealership.
  4. Make a list of modifications the car has besides performance mods (audio, security, lighting, air suspension, etc.)

  1. Firmware – Make sure your Accessport is using updated and current firmware.
    1. Accessport Manager is free software that can be used for checking and updating Accessport firmware.
    2. Click Here for a tutorial on Accessport Firmware Updates.
  2. Vehicle Compatibility – Make sure the Accessport you have is the correct model for your vehicle. Please reference our website to be sure.
    1. Click “Products”  –   Enter your vehicle  –  click “View Products”  –  Select “Accessport”  –  Verify Product Code.
      AP product code
  3. Ignition Position – Make sure the key/ignition is in the “On” position, not “Accessory”, and the engine should NOT be running. This is another one that seems silly but happens all the time. Vehicles with a push-button start can often be put into this mode by pressing the button without touching the brake pedal.  (Note: This is specific to Install, Uninstall, or Reflash…not applicable to Realtime or Feature Adjustments like FFS/LC etc.)
  4. OBDII Cable and OBDII Port – Sometimes the connectivity problem is actually a physical failure of some kind.
    1. Give the OBDII cable a nice strong push into the OBDII port under the dash. Several of the vehicles we support have a very snug fitting OBDII port. It may feel like the Accessport cable is in place, but the pins may have not all seated properly. It sounds overly simple, but we recommend this to customers with positive results on a regular basis.
    2. Corrosion and Damage – Always take a close look at the male and female connections between the Accessport and OBDII Cable as well as the connections between the OBDII cable and the OBDII port on the car. Make sure there is no corrosion or damage to any of the pins inside the Accessport or the cable. Corrosion can spread from the connections to the board and ruin the entire unit.
      **Note to Northerners – Stop letting the AP dangle to the floorboard when it’s snowy. Wet floor-mats are the number one cause of corrosion on the cable :)
    3. Cable Damage – Inspect the full length of the OBDII cable. Kinks in the chord or torn/melted insulation is an often overlooked sign of larger problems.  It can also mean that getting a new cable is a simple fix for the problem. 

      Common Examples of External Damage (Click images to enlarge)
      Keep in mind that similar damage or corrosion may occur on the OBDII pins/wiring under the dash. So make sure to inspect that as well.

      V3 Cable Corrosion cropped V2b cable corroded cropped 2 ap-serial-bad crop Cracked Bezel cropped w arrows 2 Bad Pin w Arrow cropped V3 Broken Pin
       Corrosion  Damaged bezel/pins


  5. Battery Voltage – This problem could easily be first on the troubleshooting list due to frequency, but it’s sometimes the most ambiguous and difficult to track down. Maintaining proper voltage when trying to communicate with and alter information on your car’s ECU is incredibly important.
    1. Battery – Naturally, the first thing to check is the battery itself. Inspect for corrosion or a loose connection on the terminals and leads. Check voltage with a multimeter if possible. When batteries get old or have died multiple times requiring a jump-start they are much more likely to cause trouble when tuning.
      1. USE A BATTERY CHARGER! – The warning screen is there for a reason. Is it possible to successfully flash some cars without one? Yes, but there is also a reason why many high-quality battery chargers have a setting specifically for flashing an ECU. (Note: DO NOT USE A JUMPER OR TENDER. You want the charger to deliver roughly 10-20amps at 12v)
    2. Grounding – This is super important! Many of the cars that are getting old or have been through previous modifications may have worn/corroded/or modified ground wiring/mounting locations. Faulty grounding can cause all kinds of problems, even hurting engine performance. Inspect grounding points as close as possible.
    3. Electrical Gremlins – Just because the battery itself is full of juice doesn’t mean that there is not a problem somewhere within the harness or grounds that would create a low power symptom at the OBDII port. Remember, it doesn’t matter how much voltage the battery can supply, that power has to make it to the ECU and Accessport/OBDII cable. Check the engine and body wiring harness and wires to the OBDII port for shorts/exposed wiring.
    4. Aftermarket Electronics – Anything that draws battery power and is not originally meant to be in the car, such as upgraded audio or alarm systems, may cause problems. Some aftermarket components like turbo-timers, secondary fuel controllers, a digital dash, etc. may even interfere with ECU communication regardless of voltage. You may need to remove or disconnect those devices temporarily when flashing.
      Using a multimeter to test voltage directly from the OBDII pins is highly recommended. This will tell you exactly what voltage the Accessport receives. For most cars, 12-14v would be the ideal range for flashing. Voltage above or below may result in communication failures before or during the flash.
  6. Foreign Tune/ROM – This is where the car’s tuning history comes into play. Customers frequently purchase used vehicles with little knowledge of the car’s past. In many cases, the car already has a tune on the ECU. If that tune is not from another Accessport, it is possible that the ECU will be “locked”. If that is the case, you have a few options:
    1. Uninstall the Previous Tune – The best option is to use the original tuning source to revert the ECU to a stock ROM. That should allow the Accessport to recognize and flash the ECU.
    2. Replace the ECU – This may not always be an option and will usually require having a dealership re-program the ECU before it will work with the car at all.
    3. COBB Reset – In some cases, we may be able to manually reset the ECU to a stock ROM. This would require contacting our support team and sending the ECU and Accessport to COBB for service. There can be a significant service fee and there is no guarantee that it will be possible.
  7. Dealership Overwrite – If you take your car to a dealership, even for minor service or maintenance, there is a chance they will attempt to update the ECU with the latest version of the factory ROM. Typically, if this happens while the Accessport is still installed, the Accessport tune will be overwritten and the car will revert to a stock tune. The main problem is that the Accessport will not be aware of the change so when you try to connect the Accessport afterward it will not be able to communicate.  If this occurs, the only option will be to contact our support team so that we can relicense your Accessport for a fresh install. Keep in mind, there will typically be a small fee for that service. Also, make sure to have a copy of the dealer service paperwork. Without proof that the ECU was overwritten by a dealership the Relicense fee is much more expensive. With all of this said, it is best to avoid this whole situation if possible. We recommend Uninstalling the Accessport any time you need to take your car to the dealer for service.  Obviously, this is not always possible.  In cases where Uninstalling the Accessport is not an option, giving your dealer’s Service Writer a heads-up would be appropriate.

If your Accessport is having trouble communicating with your car and you patiently go through each of the recommended steps you will almost always figure out the problem. If you still end up scratching your head or if you discover that the issue can not be resolved, feel free to contact us for further assistance.

Customer Support Phone: 866-922-3059
Customer Support Email:

Chris Lieber on November 16, 2018 says:

I have a CEL and my Accessport will not read codes. It will clear them but will not read. Displays no fault found.

    Marshall on November 19, 2018 says:

    Hey Chris,

    Sorry for the troubles. Shoot an email over to our Customer Service Team ( with your Accessport and vehicle information (AP serial number and firmware version, vehicle year/make/model) so we can better assist you!


Shawn Esmailzadeh on December 7, 2018 says:

lately my AP has been telling me that its detecting a corruption in my user files and isnt staying on like it should be. It not staying on may be due to my OBDII but im not sure on what i should do about the message about the corrupted files. It resets my AP after the message reappears and i dont wanna mess around with it too much.

    Adam Hill
    Adam Hill on December 10, 2018 says:

    Hi Shawn,

    That is strange. I will give your email to our support team and have someone reach out to you to help resolve the issue. Also, feel free to call in to support as well. 866-922-3059.

Todd Schafer on January 26, 2019 says:

I just got my accessport and am trying to install it on my 991.1 S but it stalls out at 31%. Says turn ignition to off, which i didn’t do and after a few minutes all the lights go black. I was able to get to recovery mode and got the car back to normal. Any suggestions?

    Adam Hill
    Adam Hill on January 29, 2019 says:

    Hi Todd,

    There are a few things that could cause that issue. First thing we always want to confirm is that there is a battery charger on the car, but I assume you already tried that. I am going to have one of my customer service reps setup a support ticket and send you an email ASAP to further troubleshoot. Also, you can call our support line at 866-922-3059. Please keep an eye out for an email.


Chris Small on April 4, 2019 says:

Hi, My AccessPort does not want to connect to my mazdaspeed anymore. I tried the points above that was applicable to me, and I am really struggling. I get an error “unable to update OBD hardware (0) and I have a lot riding on this to make it work. I have checked the cable using a multi-meter, Check the voltage on the OBD port, I updated the firmware, I service the car myself so the ecu is untouched and tried various suggestions from forums. Even Key cycling, connecting a charger etc… My small OBD Diagnostic tool does work but not the AccessPort. I don’t use it much so there is basically no wear and tear on the plugs/connections. I am not coming it right, any other suggestions that I might try?

    Adam Hill
    Adam Hill on April 4, 2019 says:

    Hi Chris,

    Thanks for contacting us. Troubleshooting questions are best handled directly with our support team since it can be a lengthy discussion that isn’t suited for the comment section. I will give your email to one of our support team members and they can set up a ticket and reach out to help you ASAP.


david buchanan on July 18, 2019 says:

how do you delete code p2009 thanks

    Marshall on July 22, 2019 says:

    Hi David,

    This could vary depending on the vehicle and modifications. However, a P2009 is typically related to the valves within an intake runner (manifold). I would recommend first inspecting all of the wiring/clips associated to the motors and sensors that control the valves. If all checks out, you may either have a bad motor or sensor.


Douglas Rice on October 8, 2019 says:

Could you guys post a list of links to recommended battery chargers to use during a flash. Maybe better yet start offering them for sale as part of an Accessport package…could make a few bucks and clear up so much of the message board chatter.

If they are really not needed maybe it doesn’t matter but since seems to be suggesting it as a “suggested requirement” it would be helpful to link us to a few options. Thanks!

    Adam Hill
    Adam Hill on October 10, 2019 says:


    That’s a good idea and we have actually considered selling one on the website. The level of need can vary quite wildly from car to car and from one the next. Some cars absolutely need them, others can often get by in the right circumstance, but our general rule of thumb is that it’s always better safe than sorry. I would never tell someone to not use one. It only takes one bricked ECU to ruin your day but it’s also important to use them properly to get the actual benefit and consistency.

    Here is one that we have in the office and would highly recommend. The ability to easily adjust amps and volts and the fact that it isn’t a jumper makes it the ideal option.


IVAN CORTEZ on October 30, 2019 says:

is there anyway to save the soft cut for launch control?
or does it automatically reset to 4k?

    Adam Hill
    Adam Hill on October 30, 2019 says:


    That depends on the memory ability of the factory ECU. So it varies from car to car. We allow it when possible, otherwise, it’s usually not an option.