Customer FAQs Discover answers to the most frequently asked questions from ADT customers with the click of a button. 1. What causes a trouble signal? A trouble signal (sometimes indicated in the alarm history by the abbreviation TR) indicates a possible problem or difficulty with your security system, such as a loose wire, a poorly aligned sensor or a low battery status. If you believe your issue is related to a peripheral device you may try troubleshooting the problem from our Sensor Troubleshooting page to determine if a service visit is necessary.