Note: The following article is a best-effort reference for our customers and is provided "as-is" without any express or implied warranty. does not provide detailed troubleshooting as these are potentially complex tuner problems, not unlocking ones. Please proceed at your own risk.

Most customers of are transferring a known working tuner from an old vehicle to a new one. Despite successfully going through the VIN Unlock process, an Error 316 is being encountered when installing on a new vehicle.

On H&S Tuners, Error 316 is a generic error that appears when tuner can't establish communications to the ECM. This could happen for a number of reasons including:

1) Broken OBDII Plug/Block/Harness (Mini Maxx)

Check the condition of the ODBII block. If you suspect this is the case, it's likely you can still get a replacement part or you can use the identical Bully Dog OBDII Block.

2) Bad HDMI Cable (Mini Maxx)

Often the HDMI cable is contorted to sharp angles which over time will result in a loose connection. Fortunately, the cable connecting the tuner to the ODBII block is a standard HDMI cable like those found on TVs. Try replacing this cable to see if the problem is fixed.

3) Corrupted/Malfunctioning Tuner

Unfortunately, not much can be done to test or establish this issue as the cause. While most customer's tuners came where known working units, the VIN unlock process does a complete factory default install of the tuner and corruption is possible.

4) Vehicle is Previously Tuned

If the vehicle you are attempting to tune has been previously tuned by another device, then there is a chance the ECM or TCM won't be recognized by the H&S Tuner. In this scenario, you may need to have the vehicle re-flashed by a dealer or mechanic back to stock.