2005 D4G starts and operates well AFTER running 10-15 min. Before warming up everything works but the speed is stuck in slow. Engine default code shows 255 only. What is a code 255? Does it match the problem I’m having? Thanks for any help.
Noticed you have questions on a few different machines. As with all questions provide has much info about the machine. Serial numbers are the number one thing to provide because of changes that happen during builds
Serial Numbers are always good to help locate accurate information quickly. However 255 on a D4G is related to some type of fault (see below0 on the position sensor for the F-N-R control. The most likely thing is that the position sensor requires calibration. Even if it is found that the sensor is bad and it needs to be replaced the new one would still require calibration. Unfortunately the onboard electronics on the D4G have limited self-diagnostic capability so this is a job for Cat ET, both to identify the exact Diagnostic Code (there are four possibilities all related to this one sensor) that's setting the warning on the panel. It doesn't necessarily have to be a dealer job, there may be local independents near you who also have the same diagnostic capabilities.