An internal variable will change due to computations in the program module. An externalvariable will change due to other changes (external input).
Internal Control Module Keep Alive memory
How do you change the wiper control module on a 2006 Ford Focus
There isn't an external relay. The FCM (front control module on the fuse box under the hood) controls the lights through internal circuitry.
P0601 Internal Control Module Memory Check Sum ErrorThe engine computer has failed.P0601 Internal Control Module Memory Check Sum ErrorThe engine computer has failed.
The computer needs replaced.
How do you change the ignition control module in a 1988 Chevy Silverado 5.7L
Trouble code P0606 means: Control Module Internal Performance Trouble code P0607 means: Control Module Performance
PO613 Transmission Control Module Fault. Internal failure of the module. Take the vehicle to a professional for repair.
External Air temperature control, the unit in the dash where you control the AC and Heater
I found the answer at http://www.obd-codes.com/p0601. It says that the Powertrain Control Module (PCM) needs to be replaced.
OBD-II code PO61B, Internal Control Module Torque Calculation ...