Amarok Speedometer & Cruise Control System Failure Fix

Having dealt with similar electrical system malfunctions on my 2012 VW Tiguan diesel, I can share my experience. The symptoms you describe match what I encountered, particularly the non-functional cruise control and speedometer issues. After running diagnostics, my workshop found a faulty actuator connection, specifically a damaged cable and loose plug connection to the cruise control module. The repair involved replacing the wiring harness and securing the connection properly. Total cost was 95€ for parts and labor, which seems reasonable given the technical nature of the repair. The cruise control system is often interconnected with multiple control modules, which explains why a single faulty connection can trigger various electrical issues across different systems. Before proceeding further, could you share: Have you noticed any warning lights on the dashboard? Does the speedometer malfunction occur constantly or intermittently? Are there any other electrical systems showing unusual behavior? What specific error codes did your scan reveal? This information would help determine if your issue matches the root cause I experienced and could save you time at the workshop.

Thanks for sharing those details. I just had my service done at 75760km and can confirm the error codes I'm getting are P1101 and P0638. Since your feedback, I did some additional checks. The throttle body seems to respond erratically when testing with the diagnostic tool. The steering wheel buttons for the cruise control have zero response now, while other steering wheel controls still work normally. The dashboard warning light only appears after the engine has been running for about 10 minutes. When it does show up, the speedometer goes completely blank. These symptoms really match what you experienced. I will have the actuator connections checked first before replacing any major components. Would you happen to know if this could also affect the throttle body readings I'm seeing?

Based on those error codes and your additional symptoms, your throttle body issues are likely connected to the actuator malfunction I experienced. In my case, the erratic throttle body readings were actually a secondary effect of the faulty cruise control connections. The P1101 and P0638 codes typically point to a throttle body control system malfunction. However, when these appear alongside cruise control and speedometer issues, it often indicates a broader electrical problem rather than a faulty throttle body itself. The delayed warning light appearance matches my experience exactly. The 10-minute delay occurs as the system fully warms up and the electronic throttle control system completes its diagnostic checks. In my repair case, fixing the actuator connections also resolved the unusual throttle body readings. The workshop explained that the cruise control system and throttle body share communication through the same control module network. When the actuator connection is compromised, it can send incorrect signals to the throttle body control system. Before authorizing any throttle body replacement, definitely have them check: All actuator wiring connections, The ground points near the throttle body, The cruise control module connections, The wiring harness for any signs of wear This systematic check ended up saving me from unnecessarily replacing the entire throttle body unit.

Thanks everyone. After getting these insights, I went ahead and had my vehicle checked at a local workshop. You were absolutely right, they found damaged wiring in the cruise control module connection, plus a corroded ground point near the fuse box. The total repair came to 120€, which included cleaning the ground connections and replacing part of the wiring harness. The throttle body turned out to be perfectly fine, just receiving incorrect signals due to the faulty wiring. After the fix, all systems are working normally again. The diagnostics now show no error codes, the cruise control is fully functional, and the speedometer works perfectly even after extended driving. Really appreciate the detailed guidance which helped pinpoint the actual issue. Saved me from potentially replacing expensive components unnecessarily. Will definitely keep an eye on those ground connections during future maintenance to prevent similar issues.