I recently bought a 2008 G35 sedan 5at w/nav. About a month ago i noticed that the milage on the car wasn't going up. I filled up with gas and reset the trip but it stayed at 0.0 for over a week. So i thought that maybe the cluster was bad. I bought a replacement cluster with similar miles installed it and it started working again, for exactly 127 miles. It has since stopped working again. The speedometer works fine and it calculates mpg, time traveled, and average speed with no issues. BUT the odometer, the trip and none of the maintenance intervals are adding milage again. Does anyone know if there is something else that controls the odo? Or maybe the VSS sends two different signals one to the speedo and one to the odo? Its just weird that it worked fine for almost a week after i replaced the cluster then just stopped working again just like the last one.

 

The speedo cluster gets all the MPG/time/speed info from the computer which is a part of the stereo/center console. The shop manual shows that the odometer gets its signal from the VSS signal which goes to the head unit first then transmits to the odometer. Sounds like the connection from the head unit to the odo could be bad. Does the shifter position signal go through properly? (i.e. - does the instrument cluster still tell you P/R/N/D etc.).

Have you run the self diagnostic mode on the computer system? If you search for the procedure it's in a thread here somewhere. The MWI and AV section of the shop manual has some info in it. Sounds like the computer is screwing up in your head unit or you have a bad connection between the head unit and odo.

 

Sorry it's taken me so long to respond. Yes, everything on the cluster works perfect except the odo and trip. I just changed the a/c amp control under the head unit and it reset my mpg and time traveled but nothing changed with the odo problem so I'm starting to lean toward a wire. I've looked through most of the schematics but they just say it runs through a can bus. Do you have any idea what wire I would need to be looking at or where I could find that information? Thanks in advance.