Experiencing issues with your Mercedes-Benz Electronic Traction System (ETS) and Anti-lock Braking System (ABS) can be concerning. Dashboard warning lights illuminating for ETS and ABS often indicate potential problems within these critical safety systems. For Mercedes-Benz owners, especially those with models like the W210 E320, understanding how to diagnose these issues is crucial. Many owners turn to OBD2 scanners as a first step in troubleshooting. The Actron Cp9135 Obd2 Auto Scanner is a popular choice for DIY mechanics and car enthusiasts due to its user-friendliness and accuracy in reading engine codes. But when those ETS and ABS lights appear and your trusted Actron CP9135 reports “no faults detected,” it’s natural to question if you’re using the right tool for the job.
One Mercedes-Benz owner, facing this exact scenario with their 1998 E320, turned to online forums for advice after their Actron CP9135 scanner couldn’t identify the ETS/ABS fault codes. They described the ETS and ABS lights activating frequently, particularly when making turns. Having already used the Actron CP9135 successfully to diagnose an ignition coil failure, they were now puzzled by its inability to read codes related to the ETS/ABS lights. This situation raises important questions about the capabilities and limitations of OBD2 scanners like the Actron CP9135 when it comes to diagnosing complex systems beyond the engine control unit (ECU).
The core issue here isn’t necessarily a fault with the Actron CP9135 itself. This scanner is designed primarily to read powertrain-related Diagnostic Trouble Codes (DTCs) as mandated by OBD2 standards. These codes are mostly related to engine and emission control systems. Systems like ETS, ABS, and Supplemental Restraint System (SRS) often operate on different communication protocols or require more specialized diagnostic tools to access their specific fault codes. Therefore, when an Actron CP9135 reports “no faults detected” in the context of ETS/ABS lights, it likely means the scanner is functioning correctly but is simply not equipped to communicate with the control modules responsible for these systems on your Mercedes-Benz.
So, what are the next steps when your Actron CP9135 OBD2 Auto Scanner doesn’t pick up ETS/ABS codes?
Firstly, it’s important to understand the different types of automotive scanners. While basic OBD2 scanners like the Actron CP9135 are excellent for engine-related issues, diagnosing systems like ETS and ABS often requires a scanner with enhanced diagnostic capabilities. These enhanced scanners can communicate with a wider range of vehicle modules and access manufacturer-specific codes beyond the standard OBD2 protocols. For Mercedes-Benz vehicles, a scanner that supports Mercedes-Benz specific diagnostic protocols is highly recommended for reading ETS/ABS codes.
Secondly, consider the potential causes for ETS/ABS lights illuminating, even if your scanner isn’t immediately providing codes. As the Mercedes-Benz owner in the forum post mentioned, several factors can trigger these lights:
- Wheel Speed Sensors: These sensors are crucial for both ABS and ETS to function correctly. A faulty wheel speed sensor is a common culprit for ETS/ABS light activation, especially when turning.
- Brake Light Switch: A malfunctioning brake light switch can interfere with various vehicle systems, including ETS and ABS. It’s a relatively inexpensive and common part to fail.
- Steering Angle Sensor: This sensor provides information about the steering wheel’s position and angle, which is vital for ETS. Issues with this sensor can trigger warning lights.
- Battery Voltage: Low or unstable battery voltage can sometimes cause spurious fault codes and trigger warning lights in various electronic systems.
- Faulty Bulbs: Believe it or not, even a burnt-out brake light bulb can, in some cases, trigger ETS/ABS warnings on certain vehicles due to the integrated nature of the systems. The forum post mentions a brake light issue, which could be relevant.
Regarding the specific questions raised by the Mercedes-Benz owner:
- Do I need to purchase a different type of scanner to retrieve the ETS/ABS codes? Likely, yes. While the Actron CP9135 is a capable OBD2 scanner for engine diagnostics, it may not be sufficient for reading ETS/ABS codes on a 1998 Mercedes-Benz E320. A scanner with enhanced diagnostic capabilities, specifically one that supports Mercedes-Benz protocols, is recommended.
- Should I use my scanner to reset the IM Readiness functions? Resetting IM Readiness functions is generally used after repairs to emission-related systems to prepare for smog checks. It’s not directly related to diagnosing ETS/ABS issues and is unlikely to be helpful in this situation.
- Could a brake light issue be causing the ETS/ABS lights to activate? Yes, it’s possible. A faulty brake light circuit or bulb issue can sometimes trigger ETS/ABS warnings. Addressing the inoperable brake light is advisable as part of the troubleshooting process.
- Should I replace the stop light switch again? While the stop light switch was recently replaced, and tested, it’s not impossible for a new part to be faulty or for the issue to be related to the wiring or connections to the switch. However, before replacing it again, it would be more effective to get the ETS/ABS system scanned with a compatible scanner to pinpoint the actual fault code.
In conclusion, while the Actron CP9135 OBD2 Auto Scanner is a valuable tool for diagnosing engine-related problems, it may not be comprehensive enough for diagnosing ETS and ABS issues on older Mercedes-Benz models like the W210 E320. When faced with ETS/ABS warning lights and a “no faults detected” message from your Actron CP9135, it’s advisable to seek out a scanner with enhanced diagnostic capabilities or consult a professional mechanic who has access to more advanced diagnostic equipment. Understanding the limitations of your OBD2 scanner and knowing when to seek more specialized tools is key to effective car maintenance and repair.
