T-Roc ABS Warning: Speed Sensor Issues & Solutions

Having dealt with a similar issue on my 2016 VW Golf with the 1.4 TSI engine, I can share my experience. The symptoms were identical, persistent ABS warning light and unreliable traction control. After seeing the malfunction on my dashboard, I took it to a workshop where they ran a full diagnostic scan. The ECM reported multiple fault codes related to the ABS control unit. Initially, they checked all speed sensors and wiring, but everything tested fine. The root cause turned out to be a defective ABS control unit. The workshop confirmed this after eliminating other potential causes like wheel sensors and wiring harness issues. The repair involved replacing the complete ABS control unit and recalibrating the system, which cost around 1000€ including parts and labor. The speedometer also showed erratic behavior before the fix, which was resolved after the control unit replacement. Total repair time was about 4 hours. To provide more specific guidance for your case, could you share: Any additional warning lights on your dashboard? Does the speedometer show accurate readings? Have you noticed any unusual brake behavior? Did you get any specific error codes from previous diagnostics?

Latest service was done at 30000km and so far the workshop has not been able to fix the issue. I also have the same symptoms with speedometer readings fluctuating when driving at constant speed on the highway. The transmission also feels rough when shifting into first gear. The malfunction shows up mostly after driving for about 30 minutes. You mentioned checking all sensors. My workshop charged 150€ just for the diagnostic scan but did not check the wiring thoroughly. The ABS warning on the dashboard is now constant. Will get it checked again and ask specifically about the control unit since your case sounds very similar to mine. Good to know about the repair time and costs for planning purposes. Any other electronic issues I should mention to the workshop when checking the control unit? Want to make full use of the next diagnostic session.

Based on your description of the speedometer fluctuations and transmission behavior, these symptoms strongly match what I experienced before getting the ABS control unit replaced. The intermittent nature after 30 minutes of driving is particularly familiar. During my repair process, I learned that faulty ABS control units can cause a chain reaction of electronic issues. The input signals from wheel speed sensors to the ECM get corrupted, affecting both the speedometer readings and transmission shift patterns. This happens because modern transmissions rely heavily on accurate speed sensor data. Make sure your workshop checks: The entire wiring harness between the ABS control unit and ECM, All ground connections near the ABS module, The interface between the speed sensors and transmission control, Signal consistency between all wheel sensors at different speeds My transmission shifting issues completely resolved after the control unit replacement. The constant ABS warning light and erratic speedometer behavior were just symptoms of the main problem with the control unit itself. For the next diagnostic, request they monitor real-time sensor data while the vehicle is warm, as the issues become more apparent after extended driving. The workshop should also verify the odometer signal accuracy since this ties into both speedometer and transmission operation. The 150€ diagnostic fee seems standard, but ensure they perform a thorough system analysis this time. The total repair cost around 1000€ proved worthwhile as it resolved all related issues simultaneously.

Thanks for the additional information about monitoring sensor data during warm conditions. That makes a lot of sense given the timing of my issues. I will definitely have them check all those connections and wiring points you mentioned. The transmission shifting problem becoming more noticeable after warm-up matches exactly what I am experiencing. My ABS malfunction and dashboard warnings also follow that same pattern. Good to know that fixing the control unit resolved both the speedometer and transmission problems in your case. I have booked another workshop appointment for next week. Will ask them to specifically check the ECM communication with the ABS module and verify all the ground connections. Expecting similar repair costs around 1000€ based on your experience, which helps with planning. Really hoping this fixes all the related issues like it did in your case. The constant warning lights and unreliable traction control are quite concerning.