Section 78.3 SPN 975/FMI 5

Section 78.3
SPN 975/FMI 5

This fault code indicates that there is an open circuit.‪

Section 78.3.1
Open Circuit Check

Check for open as follows:‪

  1. Disconnect the fan control solenoid connector.
  2. Turn the ignition ON (key ON, engine OFF).
  3. Measure the voltage between pin 1 and 2 of the fan control solenoid connector.
    1. If the voltage is less than 11.5 volts, go to step 5 .
    2. If the voltage is between 11.5 and 13.5 volts, replace the fan control solenoid. Refer to "78.3.1.1 Verify Repairs" .
  4. Measure the voltage between pin 2 of the fan control solenoid connector and ground.
    1. If the voltage is less than 11.5 volts, repair the open between pin 2 of the fan control solenoid connector and pin 91 of the 120–pin MCM connector. Refer to "78.3.1.1 Verify Repairs" .
    2. If the voltage is greater than 11.5, repair the open between pin 1 of the fan control solenoid connector and pin 33 of the 120–pin MCM connector. Refer to "78.3.1.1 Verify Repairs" .
Section 78.3.1.1
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.


EPA07 MBE 4000 DDEC VI Troubleshooting Guide - 6SE568
Generated on 10-13-2008

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