MBE 4000 DDEC VI Troubleshooting – Section 50.2 SPN 625/FMI 4

Section 50.2
SPN 625/FMI 4

This fault indicates that the CAN propriety data link to the CPC has shorted.‪

Note: The following diagnostic pertains to a fault reported from the CPC.

Section 50.2.1
Check for Short Circuit

Check as follows:‪

1. Turn ignition OFF, disconnect the 21–pin MCM connector.
2. Disconnect the CPC #4 connector.
3. Measure the resistance between pins 1 and 3 of the CPC #4 connector.
   1. If the resistance is greater than 5 Ω, go to step 4 .
   2. If the resistance is less than 5 Ω, repair the short in the wires between pins 1 and 3 of the CPC #4 connector and pins 13 and 19 of the 21–pin MCM connector. Refer to "51.2.1.1 Verify Repairs" .
4. Measure the resistance between pin 1 of the CPC #4 connector and ground.
   1. If the resistance is greater than 5 Ω, go to step 5 .
   2. If the resistance is less than 5 Ω, repair the short to ground between pin 1 of the CPC #4 connector and ground. Refer to "51.2.1.1 Verify Repairs" .
5. Measure the resistance between pin 3 of the CPC #4 connector and ground.
   1. If the resistance is greater than 5 Ω, go to step 6 .
   2. If the resistance is less than 5 Ω, repair the short to ground between pin 3 of the CPC #4 connector and ground. Refer to "51.2.1.1 Verify Repairs" .
6. Measure the resistance between pin 1 of the CPC #4 connector and pin 19 of the 21–pin MCM connector.
   1. If the resistance is greater than 5 Ω, repair the open between pin 1 of the CPC #4 connector and pin 19 of the 21–pin MCM connector. Refer to "51.2.1.1 Verify Repairs" .
   2. If the resistance is less than 5 Ω, go to step 7 .
7. Measure the resistance between pin 3 of the CPC #4 connector and pin 13 of the 21–pin MCM connector.
   1. If the resistance is greater than 5 Ω, repair the open between pin 3 of the CPC #4 connector and pin 13 of the 21–pin MCM connector. Refer to "51.2.1.1 Verify Repairs" .
   2. If the resistance is less than 5 Ω, call the DDC Customer Support Center (313–592–5800).

Section 50.2.1.1
Verify Repairs

Verify repairs as follows:‪

1. Turn ignition OFF.
2. Reconnect any electrical connections that were disconnected to perform the diagnosis.
3. Clear codes with DDDL 7.0 or latest version.
4. Start and bring engine up to operating temperature (over 140°F/60°C).
5. Verify operation is satisfactory and no warning lamps illuminate. If warning lamps illuminate, troubleshoot the codes. If assistance is required, call the Detroit Diesel Customer Support Center at 313–592–5800.