I have an 03 E500 I’ve been working on and my problem is the engine temp gauge in the cluster just maxes out after the car starts and runs for a couple minutes. On the scan tool it’s reading just fine. Swapped the cluster out with a know good one to see and sure enough the temp gauge operates correctly in that one. So my question is can I just swap circuit boards on the coolant gauge or does the whole cluster have to be replaced?