Speedometer problem

Do you have any codes? As I was reading, I was suspect a vehicle speed sensor but you have an input and output speed sensor. Do you know which one you replaced? Was there a reason you replaced it or were you guessing at what it could be?

Let's start with checking for codes and which speed sensor you replaced and we can go from there. Thanks

So you were correct that there were no codes that appear to relate to this issue. Included the MAF info for reference at this point.

Was the check engine light on when this was happening? Is the vehicle still acting up?

I also attached the location of the speed sensors. Was the location of the sensor you replace #2 or was it in the tail shaft?

It feels like we are missing something so we are going to have to work through this until we find the missing piece.

I am sorry. I should have been more specific. Do you know which transmission you have? Either the 4L60E or 4L80E?

If the sensor was in the location shown in the first attachment then you have the 60. If it was in the second attachment #2 then you have the 80. This makes a difference because the speedometer and shifting are determined differently.

If you have the 60 then you only have the one sensor. The 80 has two so we need to make sure we know what we are working with or we are going to get really confused (more then currently).

The difference of the two sensor locations is the 60 is in the tail shaft and the 80 as the rear sensor just over the rear of the trans pan.

Okay. That is good news and bad news. Good news is, I think I know how we can find out what the issue is. Bad news is, we need to monitor the data from the PCM which means we need a scan tool that can do that.

Take a look at the wiring diagram. This is the vehicle speed sensor to the PCM, which shares the data with the throttle actuator control module.

The thing that tipped me towards this was that you tried to use the cruise control and this happened all of a sudden. The thing that I can't figure out is why you have no codes. This is why we need to monitor what the PCM is seeing.

Also, I doubt this is the issue because you have no codes but check the fuses in the second attachment. These are the fuses related to the cruise and I suppose they could cause an issue like this. Again, the no codes thing is throwing me off.

Let me know if you have good fuses and then if you have access to a scan tool so we can see what the speed sensor is telling the PCM.