Encountering issues with your Mercedes-Benz Electronic Traction System (ETS) and Anti-lock Braking System (ABS) can be concerning, especially when warning lights illuminate on your dashboard. One Mercedes-Benz owner using a 1998 W210 E320 turned to the Actron Cp9135 Obdii Auto Scanner for help, initially praising its effectiveness in diagnosing an ignition coil failure. However, when faced with persistent ETS and ABS lights, the scanner reported “No Faults Detected,” leading to questions about scanner capabilities and potential diagnostic steps.
This situation raises important questions for DIY mechanics and car owners relying on OBDII scanners like the Actron CP9135 for vehicle diagnostics, particularly when dealing with sophisticated systems like ETS and ABS in European vehicles. Let’s delve into these questions to understand how to effectively use your Actron CP9135 scanner and what to do when it doesn’t seem to catch the problem.
Understanding OBDII Scanners and System-Specific Codes
The primary question raised is whether the Actron CP9135 OBDII Auto Scanner is capable of reading ETS/ABS codes. Standard OBDII scanners, like the CP9135, are designed to read generic diagnostic trouble codes (DTCs) mandated for emissions-related systems across all OBDII-compliant vehicles (generally post-1996 in the US). These codes are standardized and cover engine, transmission, and some basic sensor faults that impact emissions.
However, systems like ETS, ABS, and SRS (Supplemental Restraint System – airbags) are often controlled by vehicle-specific modules and may use proprietary diagnostic codes that go beyond the generic OBDII standards. Therefore, while the Actron CP9135 is excellent for reading engine-related fault codes, it may not be designed to access the deeper, system-specific codes for ETS and ABS in a Mercedes-Benz W210.
Answer to Question 1: You might need a scanner with enhanced diagnostic capabilities beyond standard OBDII to retrieve ETS/ABS codes from your 1998 Mercedes W210. These enhanced scanners can often communicate with manufacturer-specific modules and read proprietary fault codes.
Resetting IM Readiness Functions with the Actron CP9135
The question about resetting IM Readiness functions is pertinent for vehicle maintenance and emissions testing. IM Readiness monitors indicate whether a vehicle’s emissions control systems have been tested and are ready for an emissions inspection. The Actron CP9135, as an OBDII scanner, typically does have the capability to reset these monitors after a fault has been repaired.
However, resetting IM Readiness monitors should not be used as a troubleshooting step for ETS/ABS lights. It’s generally used after repairs to clear codes and reset the monitors so the vehicle can pass an emissions test. It won’t resolve underlying ETS/ABS issues and is unrelated to reading system-specific fault codes.
Answer to Question 2: Using your scanner to reset IM Readiness functions is generally for post-repair procedures related to emissions, not for diagnosing ETS/ABS issues.
Brake Light Issues and ETS/ABS Activation
The user mentions an inoperable brake light and wonders if this could trigger the ETS/ABS lights. This is a very relevant point. The brake light system is often integrated with the ABS and ETS for safety reasons. A malfunctioning brake light circuit, especially one with grounding or arcing issues, can indeed cause erratic signals in the electrical system that might trigger ETS/ABS warnings.
Furthermore, the brake light switch itself is a common culprit for ETS/ABS light issues in Mercedes-Benz vehicles. Although the user replaced the stop light switch, a faulty new switch or incorrect installation could still be a problem.
Answer to Question 3: Yes, a brake light issue, including a faulty bulb, wiring problem, or a malfunctioning brake light switch, can absolutely cause ETS/ABS lights to activate.
Answer to Question 4: While you’ve replaced the stop light switch, it’s still a plausible cause. Even new parts can be defective, or the issue might be with the switch adjustment or related wiring, not just the switch itself. Re-inspecting or even replacing the switch again could be a worthwhile step if other diagnostics don’t reveal the issue.
Next Steps for Diagnosing ETS/ABS Issues
Given that the Actron CP9135 isn’t showing fault codes for the ETS/ABS lights, here are recommended next steps:
-
Enhanced Scanner: Consider using a more advanced scan tool that is capable of reading Mercedes-Benz specific codes. Many professional garages and some advanced DIY scanners offer this functionality. This will likely provide the specific fault codes related to the ETS/ABS system, pinpointing the problem area.
-
Visual Inspection: Thoroughly inspect the brake light circuit, check all brake light bulbs, and examine the wiring for any signs of damage, corrosion, or bad grounds.
-
Wheel Speed Sensors: Wheel speed sensors are crucial for ABS and ETS operation. Inspect the wheel speed sensors and their wiring at each wheel for damage or disconnection. These are common causes of ABS/ETS issues, especially if the lights come on during turns as the user described, which can stress sensor wiring.
-
Steering Angle Sensor: The steering angle sensor is also part of the ETS/ABS system. While less common, it could be a potential issue, particularly if the lights come on during turns. An enhanced scanner may help diagnose issues with this sensor.
-
Battery Voltage: While less likely to directly cause “no faults detected” on a basic scanner, ensure your battery voltage is healthy and stable, as low voltage can sometimes cause erratic electronic system behavior.
Conclusion
The Actron CP9135 OBDII Auto Scanner is a valuable tool for diagnosing many common car problems, particularly those related to engine and emissions. However, for system-specific issues like ETS and ABS in vehicles like a Mercedes-Benz W210, it may be necessary to use a more advanced diagnostic tool to access the relevant fault codes.
Don’t dismiss the basics: thoroughly check your brake lights and related wiring, as this is a surprisingly common cause of ETS/ABS warnings. By systematically investigating these areas and potentially using a more capable scanner, you can effectively troubleshoot the ETS/ABS lights on your Mercedes-Benz.
