The Actron Cp9135 Obd2 Scanner is a popular tool for car owners looking to diagnose check engine lights and basic vehicle problems themselves. Its user-friendly interface and accuracy in reading powertrain codes have made it a go-to device for many DIY mechanics. However, when it comes to more complex issues like ABS (Anti-lock Braking System) and ETS (Electronic Traction System) lights, users might find themselves in a situation where the CP9135 reports “no faults detected,” despite warning lights being illuminated on the dashboard.
Understanding the capabilities and limitations of OBD2 scanners like the Actron CP9135 is crucial for effective car diagnostics. These scanners are primarily designed to read Diagnostic Trouble Codes (DTCs) related to the engine and transmission – the powertrain. This is mandated by OBD2 standards to monitor emissions-related systems. For diagnosing issues within these systems, the CP9135 is quite capable, as evidenced by its success in identifying an ignition coil failure in the original user’s experience.
However, systems like ABS, ETS, SRS (Supplemental Restraint System – airbags), and body control modules often operate on different communication protocols or are considered outside the scope of basic OBD2 emissions regulations. Therefore, a standard OBD2 scanner like the Actron CP9135 might not be equipped to communicate with these systems and retrieve their specific fault codes. When the ETS and ABS lights illuminate, especially in scenarios like turning, it indicates potential problems within the chassis and braking systems, which are distinct from engine or transmission issues.
For diagnosing ABS and ETS lights, particularly in European vehicles like Mercedes-Benz, a scanner with enhanced diagnostic capabilities is often required. These advanced scanners can access a wider range of vehicle systems beyond just the powertrain, reading codes from modules controlling braking, stability, and chassis functions. Possible causes for ETS/ABS lights in older Mercedes models, as mentioned in online forums, include brake light switches, wheel speed sensors, steering angle sensors, and voltage issues. These components are integral to the ABS and ETS systems and their malfunctions can trigger the warning lights.
Therefore, if your Actron CP9135 OBD2 scanner reports “no faults detected” while your ETS/ABS lights are on, it doesn’t necessarily mean there are no problems. It likely indicates that the issue lies within systems that the CP9135 is not designed to read. To properly diagnose these lights, consider using a more advanced scan tool capable of reading ABS/ETS codes or seeking professional diagnosis from a mechanic equipped with such tools. While the Actron CP9135 is excellent for basic engine and transmission diagnostics, understanding its limitations is key to effective vehicle troubleshooting.
