Speedometer or DIC
Thread Starter
Le Mans Master
Joined: May 2006
Posts: 8,824
Likes: 3
From: The left Coast
St. Jude Donor '08
Speedometer or DIC
My cruise control was not working so the dealer reflashed the computer which meant I had to get the tune reflashed. The cruise is working but now I don't know if the speedometer is correct or the DIC. Both my speedo and HUD show the same speed but when the cruise engages the DIC indicates a speed about 4 to 5 mph faster. You would think the same computer that reads the speed for the hud would be the same as the DIC. 
Tech Contributor
Joined: Dec 2006
Posts: 10,962
Likes: 29
From: Van Buren Arkansas
Wounded Warrior Escort '11
I know on the C-5's the HUD information comes from the Cluster therefore I'm guessing its the same on the C-6's. I would venture a guess that your cluster has an issue with the hud output when you turn on the cruise. The speed information probably comes from the ECM/PCM into the cluster. But turning on the cruise is something that the ECM/PCM and if it applies on the C-6, a TAC module too. Was the speedometer and HUD correct before the reflashing, when the cruise was turned on?
