I am currently having issues with a 2015 BMW. I thought the ECU might be the problem. Thanks to ECU Pros, I was able to send out the unit for testing. It turns out the ECU is functioning properly and is not the issue. ECU Pro was honest and fast. They specified 3 to 5 days to test the ECU after receiving it and they got the work done in this time and sent it back to me. The only reason I am giving 4 stars is because I wish they would have communicated an estimated testing date. I received an email saying they received the ECU. If they had added an estimated testing date, I would have given 5 stars.