It’s a common concern for car owners: can your OBD2 scanner itself be the reason you’re seeing those confusing error codes? Many believe that these scanners might mess with your car’s computer system, but the truth is generally reassuring. Let’s dive into whether your OBD2 scanner could be giving you false readings.
Are OBD2 Scanners Supposed to Cause Errors?
Typically, no. OBD2 scanners are designed as “read-only” devices. Think of them as listeners, not talkers who change the conversation. They communicate with your car’s Powertrain Control Module (PCM) to read data, including diagnostic trouble codes (DTCs). They are not built to alter or reprogram your car’s computer in any way during normal diagnostic scans. When you use a scanner to clear codes, it’s simply sending a command to the PCM to erase existing codes – it’s an instruction, not a rewrite of the system’s core programming.
Potential Risks – When Could a Scanner Cause Issues?
While highly unlikely in standard use, there are theoretical scenarios where problems could arise:
- Extreme Electrical Events: In highly improbable situations, like connecting a welding device directly to your OBD2 port (please don’t!), you could send excessive voltage and fry electronic components. This is not a scanner issue, but rather extreme misuse of the port itself.
- Improper Reprogramming Attempts: If you were to use specialized tools to attempt to remap engine parameters via the OBD2 port and interrupt the process midway, you could potentially corrupt the PCM’s software. However, standard OBD2 scanners for code reading and clearing are not designed for this type of advanced reprogramming.
- Faulty or Poorly Designed Scanners: While rare with reputable brands, a poorly manufactured or malfunctioning scanner could theoretically introduce electrical anomalies. However, the vast majority of scanners, including popular ELM327 clones, are designed to be safe for your vehicle’s electronics when used as intended.
ELM 327 Clones: Are They Risky?
The ELM327 chip is widely used in affordable OBD2 scanners. While concerns about clones exist, the risk of damage from using a standard ELM327 clone for reading and clearing codes is exceedingly low. Millions are in use without causing widespread issues. These devices are designed to operate within safe voltage and current ranges for your car’s system. Electrical short circuits are always a possibility with any electronic device, but the probability is minimal under normal usage conditions.
Conclusion: Focus on Accurate Diagnosis
If you are experiencing error codes and suspect your scanner, it’s far more likely that the codes are genuine indicators of an issue within your vehicle, not a problem caused by the scanner itself. Focus on properly diagnosing the reasons behind the codes. Investigate potential mechanical or electrical problems in your car rather than blaming the diagnostic tool that is simply reporting the information it retrieves from your car’s computer. If you are unsure, consult a professional mechanic to verify the codes and diagnose any underlying problems accurately.
