Section 50.1
SPN 609/FMI 12

This diagnostic condition is typically MCM failed or programmed incorrectly.‪

Section 50.1.1
MCM Parameter Check

Check as follows:‪

1. Using your diagnostic tool, reset the parameters on the MCM.
   1. If fault code 233/12 is not active after resetting parameters, troubleshooting is finished.
   2. If fault code 233/12 is still active after resetting parameters, go to step 2 .
2. Check the MCM parameters to ensure they are correct for the vehicle configuration.
   1. If parameters are not correct, reset parameters on the MCM.
   2. If parameters are correct, contact Detroit Diesel Customer Support Center (313–592–5800) for authorization to replace the MCM. Set parameters on the new MCM.