MBE 4000 DDEC VI Troubleshooting – Section 125.2 SPN 3663/FMI 14

Section 125.2
SPN 3663/FMI 14

This diagnosis is typically the Electronic Unit Pump current is below normal or an open circuit fault.‪

Section 125.2.1
Open Circuit Check

Check as follows:‪

1. Check for multiple codes.
   1. If fault 3662/14 and 3664/14 are active in addition to 3663/14, contact the Detroit Diesel Customer Support Center (313–592–5800) for MCM replacement.
   2. If only fault code 3663/14 is active, go to the next step.
2. Measure the resistance across Electronic Unit Pump #5. See Figure "Electronic Unit Pump #5" .
   

   Figure 1. Electronic Unit Pump #5

   1. If the resistance is greater than 3 Ω, replace Electronic Unit Pump #5.
   2. If the resistance is less than 3 Ω, go to the next step.
3. Disconnect the MCM 120–pin connector.
4. Measure the resistance between either pin of the Electronic Unit Pump #5 connector and pin 9 of the MCM 120–pin connector.
   1. If the resistance is greater than 3 Ω, repair the open between pin 9 of the 120–pin MCM connector and Electronic Unit Pump #5. Refer to "125.2.1.1 Verify Repairs" .
   2. If the resistance is less than 3 Ω, repair the open between pin 8 of the 120–pin MCM connector and Electronic Unit Pump #5. Refer to "125.2.1.1 Verify Repairs" .

Section 125.2.1.1
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.