MBE 4000 DDEC VI Troubleshooting – Section 98.3 SPN 2791/FMI 5

Section 98.3
SPN 2791/FMI 5

This diagnostic condition is typically an open circuit fault.‪

Section 98.3.1
Open Circuit Check

Check for open as follows:‪

1. Disconnect the EGR valve connector.
2. Turn the ignition ON (key ON, engine OFF).
3. Measure the voltage between pin 2 and pin 3 of the EGR valve connector. See Figure "EGR Valve" .
   

   Figure 1. EGR Valve

   1. If the voltage is between 11 and 13 volts, go to step 6 .
   2. If the voltage is less than 11 volts, go to step 4 .
4. Measure voltage between pin 2 of EGR valve connector and ground.
   1. If the voltage is between 11 and 13 volts, repair the open in the wire between pin 67 of the 120–pin MCM connector and pin 3 of the EGR valve connector. Refer to "98.3.1.1 Verify Repairs" .
   2. If the voltage is less than 11 volts, go to step 5 .
5. Turn the ignition OFF and measure the resistance between pin 2 of EGR valve connector and pin 62 of the 120–pin MCM connector.
   1. If the resistance is greater than 3 Ω, repair the open circuit in the wire between pin 62 of the 120–pin MCM connector and pin 2 of EGR valve connector. Refer to "98.3.1.1 Verify Repairs" .
   2. If the resistance is less than 3 Ω, replace the MCM.
6. Turn the ignition OFF and measure the resistance between pin 1 of the EGR valve connector and pin 61 of the 120–pin MCM connector.
   1. If the resistance is greater than 3 Ω, repair the open circuit in the wire between pin 61 of the 120–pin MCM connector and pin 1 of EGR valve connector. Refer to "98.3.1.1 Verify Repairs" .
   2. If the resistance is less than 3 Ω, replace the EGR valve.

Section 98.3.1.1
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.