A 2010 Kenworth T800 recently received an ECM update at a Kenworth dealership while being serviced for a transmission yoke issue. Shortly after, the truck began experiencing intermittent throttle problems, with the throttle position only reaching 50-70% instead of the expected 100%. Before the update, the throttle functioned correctly. A technician confirmed the full throttle range prior to the driver leaving the dealership. However, the issue surfaced just a few miles down the road. Upon returning to the dealership, the technician could only achieve a 50-70% throttle response when plugged in. The dealership attributed the problem to driver error, but this explanation is unsatisfactory given the problem’s onset immediately after the ECM update.
Could the erratic 70% throttle be linked to the recent ECM reflash? The update’s source (CD, website download) and specific content remain unknown. Further investigation with the dealership on Monday will hopefully shed light on these details. Other potential causes include a failing throttle position sensor (TPS).
Seeking a second opinion from a nearby Cummins dealer is being considered. Providing the engine serial number to a Cummins or Kenworth specialist might aid in diagnosis.
