Many car owners are turning to OBD2 scanners as a handy tool for diagnosing car problems themselves. These devices are affordable and readily available, promising to empower you with insights into your vehicle’s health. But with this increased accessibility comes a common concern: Can You Damage Your Car Using An Obd2 Scanner? This question is more relevant than ever as more people take a DIY approach to car maintenance.
Recently, I had a firsthand experience that made me question the safety of using these scanners. My 2000 Nissan Altima started acting up. It would stall, especially when accelerating or under load. The “Service Engine Soon” light was on, which was my first clue that something wasn’t right. A friend, who had an older OTC scanner, offered to help me check for error codes. This is where things took an unexpected turn.
The Initial Problem: Stalling and the Service Engine Soon Light
My Nissan Altima’s main symptom was stalling. Imagine driving and suddenly your engine just cuts out – that’s exactly what was happening. It was intermittent at first, but became more frequent and concerning, particularly when trying to accelerate. Despite the stalling, the car would restart, although it would often stall again soon after, especially if I tried to drive it. The constant “Service Engine Soon” light on the dashboard was another clear indicator that there was an underlying issue that needed attention.
Introducing the OBD2 Scanner: A Friend’s Attempt and an Unexpected Consequence
Hoping to get some insight into the problem, I reached out to a friend who had an OTC OBD2 scanner. We connected his scanner to my car, hoping to pull some diagnostic trouble codes (DTCs). However, after connecting the scanner, something strange happened. The car, which was at least starting before, now wouldn’t even start at all. It would crank, meaning the engine was turning over, but it just wouldn’t fire up and run. We couldn’t even retrieve any error codes at this point because the car was completely unresponsive in terms of starting. This was definitely not the outcome we expected when trying to diagnose the stalling issue.
The Plot Twist: Car Won’t Start AFTER Scanner Use
The fact that my car went from starting (albeit poorly) to not starting at all immediately after connecting the OBD2 scanner was perplexing. Had the scanner somehow caused a new problem? It seemed unlikely, but the timing was certainly suspicious. After leaving the car overnight, I returned the next day to troubleshoot further. To my surprise, the car started again! I managed to drive it home and even performed some basic maintenance like changing the fuel filter and oil, thinking perhaps these were contributing to the stalling. The car ran okay for about a day, but then the stalling issue returned while my daughter was driving.
Is the Scanner to Blame? Exploring Potential Causes
Frustrated and determined to fix the issue myself, I decided to do some research and invest in my own OBD2 scanner. I ordered an Ancel 410 scanner from Amazon. While waiting for it to arrive, I continued to investigate the stalling problem. Through online research, specifically YouTube videos, I stumbled upon a possible culprit: a vacuum hose that had been damaged, likely by rodents. Upon inspection, I found a chewed vacuum hose that looked like it had been a winter home for some critter. Repairing this hose seemed to resolve the stalling issue, and the car ran much better. However, the “Service Engine Soon” light remained illuminated.
Once the car was running smoothly again (though with the persistent warning light), my friend returned with his OTC scanner to try and read the error codes. This time, we successfully retrieved several codes: P0100, P0505, P0325, P1490, P0446, and P0464. Interestingly, and concerningly, as soon as he connected the OBD2 scanner again, the car stalled and refused to start once more – mirroring the exact situation from the first time. It seemed increasingly likely that the scanner was somehow involved in the starting problem, even though it was intended to be a diagnostic tool.
ECM Reset to the Rescue: A Potential Solution
More online research led me to a potential explanation and solution. Apparently, in some cases, connecting an OBD2 scanner can, in fact, cause issues with the car’s Engine Control Module (ECM) or Powertrain Control Module (PCM). The theory is that sometimes the scanner can interfere with the ECM’s communication or even trigger a fault that prevents the car from starting. The suggested fix in these situations is to perform a “hard reset” of the ECM.
The hard reset procedure involves disconnecting both battery terminals and then briefly touching the disconnected positive and negative battery cables together (while they are disconnected from the battery). This action is supposed to discharge any capacitors in the ECM, effectively resetting it. I tried this procedure, carefully disconnecting both terminals and touching the cables together for about 10 seconds. And guess what? It worked! After reconnecting the battery, the car started right up again.
Lessons Learned & Tips for Using OBD2 Scanners
My experience highlights that while OBD2 scanners are generally safe and helpful tools, there’s a possibility, albeit perhaps rare, that they can cause temporary issues. Here are some key takeaways and tips based on my experience and research:
- OBD2 Scanners are generally safe: For the vast majority of users and vehicles, OBD2 scanners are perfectly safe to use and will not cause damage. They are designed to be diagnostic tools that read data without altering the car’s systems.
- Potential for ECM/PCM issues exists: In some cases, and possibly with certain older vehicles or specific scanner models, there might be a communication glitch that can temporarily affect the ECM/PCM. This seems to be more of a temporary software hiccup than actual physical damage.
- Hard reset can be a solution: If you experience a no-start condition immediately after using an OBD2 scanner, especially if the car was starting before, try performing an ECM/PCM hard reset by disconnecting and reconnecting the battery cables as described.
- Consider scanner compatibility: While OBD2 is a standardized system, there might be slight variations in how different scanners interact with different car models. Researching scanner compatibility for your specific vehicle year and make might be beneficial.
- Start with basic troubleshooting: Before assuming the scanner caused a problem, double-check basic things like battery connections, and ensure the scanner is properly connected to the OBD2 port.
- Don’t be afraid to use scanners: Despite my initial scare, OBD2 scanners are incredibly valuable tools for car owners. They can save you time and money by helping you identify problems early on. Just be aware of the potential for minor glitches and know how to address them.
In conclusion, while the question “can you damage your car using an OBD2 scanner?” might seem alarming, the answer is generally no, not in a way that causes lasting damage. However, as my experience shows, it’s possible for a scanner to trigger temporary electronic issues, particularly with starting, which can usually be resolved with a simple ECM reset. Understanding this possibility and knowing how to troubleshoot it will make you a more informed and confident user of OBD2 diagnostic tools.
