The Most Common Problems Confronted at Turn-Ons and How To Troubleshoot Them

Turning on a new or rebuilt intersection is no small task. Between short timelines – especially in big cities – and the complexity of any given intersection control system, there’s not much room for error.

But issues do arise, and we’ve got the expert troubleshooting tips to keep your intersection turn-on on track. Here are the most common problems our traffic experts have encountered:

Problem #1: There is missing, shorted, un-landed, loose, poorly connected, unlabeled or mislabeled field wiring.

Troubleshooting Solution: Review the wiring plans to insure all field wire is present, properly labeled, landed, and tested. Once you have identified the wiring, you will need to re-test to isolate the specific problems. You may need to energize individual pairs if the problem is difficult to isolate.

Problem #2: The controller is not properly programed for intersection timing.

Troubleshooting Solution: Make sure the timings provided by the consultant or agency are available at the intersection. You should have the contact information of the traffic engineer who developed the timing plan in case there are timing edits or a new timing plan needed.

Problem #3: The pedestrian buttons are not working.

Troubleshooting Solution: First, test the button by disconnecting it from the power source and powering it with an alternate source. Second, confirm it is the correct pair of wires by conducting continuity test. Finally, test the cable for a short by checking the resistance.

Problem #4: The controller is not communicating via interconnect.

Troubleshooting Solution: Check the baud rate first, then ensure the Ethernet port is enabled or disabled (whichever is appropriate). Next, test the viability of the copper or fiber interconnect.

Problem #5: The EVP is not detecting emergency vehicles.

Troubleshooting Solution: Confirm that the detectors and cards are compatible, then make sure the drain wire is connected to the panel. Test for 24VDC at the panel with field wires connected and subsequently disconnected to isolate the problem to the detector head or the card. Check for a blown fuse on the card.

Problem #6: There is no communication on the Ethernet cables.

Troubleshooting Solution: Use an Ethernet tester to check the continuity and pinouts of all Ethernet cables and jumpers.