Experiencing a no-start issue with your 2014 GMC Sierra 1500 can be frustrating, especially when your OBD2 scanner shows “no communication.” Recently, I encountered this exact problem. Hoping to pinpoint the issue, I visited a friend at a dealership, and we tried to replicate the problem. Despite using dealer software, we couldn’t find any stored codes that a regular scanner might miss. Naturally, during our tests, the truck started without a hitch. We even tried soaking the vehicle to introduce moisture, suspecting an electrical problem, but still no failure. This initial check ruled out easily detectable issues, leading us to suspect something deeper within the electrical system.
Considering past experiences, particularly with an older 07 model that had fuse block issues, we turned our attention to the fuse junction box. Although this 2014 Sierra wasn’t exhibiting the exact melting connection issue of the older model, it was a plausible area to investigate. To thoroughly test this, my friend rigged up a jump-out harness to the bottom of the fuse junction block, allowing us to test it without disturbing the original connections which initially appeared to be in good condition. The next morning confirmed our suspicion: the truck failed to start, replicating the original problem. The culprit was indeed the junction box.
Replacing the fuse junction box, a part costing around $157 from the dealer, proved to be a straightforward DIY repair. The key is to take your time removing the connectors to avoid damaging anything. Since the replacement, the truck has been running smoothly for several days, even through rainstorms, indicating the fix was successful. Curious about the failure, I disassembled the old junction box for inspection. Visually, there was no apparent damage, no signs of arcing or water ingress. However, these boxes contain a two-piece circuit board with internal circuits sandwiched inside. With the help of a friend skilled in board construction, we carefully split the board and discovered evidence of water intrusion. The water had entered through a rough, unfinished edge of the board, damaging the internal circuits – a point of entry not visible without disassembly.
This experience highlights that even without visible signs, water intrusion can cause significant electrical issues. What seemed like a complex problem with “2014 Gmc Sierra 1500 Wont Start And Obd2 No Communication” turned out to be a faulty fuse junction box. While a dealer repair might cost around $500, including parts and approximately 3 hours of labor, a DIY approach can save you significantly. In my case, including a precautionary ground wire replacement due to corrosion, the total cost was just over $200. This case serves as a reminder to consider less obvious causes like internal damage within sealed components when troubleshooting electrical issues in modern vehicles.
