Detroit DD15 EPA07 (2007-09) Fault Code: SPN 523 FMI 19 (MCM, CPC) Transmission Current Gear Signal is Erratic

NOTE: Please see the step by step troubleshooting procedures for this specific code.

PROBABLE CAUSES:
1. If any codes related to battery voltage are present, fix those first.
2. If 625-9 present, troubleshoot that instead.
3. If any engine modules have been programmed recently, check configuration.
4. Another computer module on the truck (ABS, transmission, cab, etc…) has a failure that is causing this.