MBE 900 DDEC VI Troubleshooting – Section 27.3 SPN 100/FMI 3

Section 27.3
SPN 100/FMI 3

This diagnosis is typically an Engine Oil Pressure Switch/Sensor open short-to-power fault. ‪

Section 27.3.1
Open Short to Power Check

Check as follows:‪

1. Check for multiple codes.
   1. If 100/3, 174/3, 115/3, 110/3 and 100/3 are present, repair the open between pin 55 of the 120–pin connector and the associated switches. Refer to "27.3.1.1 Verify Repairs" .
   2. If only 100/3 is present, go to step 2 .
2. Disconnect the Engine Oil Pressure Switch/Sensor. See Figure "Engine Oil Pressure Switch/Sensor" .
   

   Figure 1. Engine Oil Pressure Switch/Sensor

3. Turn the ignition ON (key ON, engine OFF).
4. Measure the voltage between pins 1 and 2 of the Engine Oil Pressure Switch/Sensor harness connector.
   1. If the voltage is between 2.5 and 3 volts, replace the Engine Oil Pressure Switch/Sensor. Refer to "27.3.1.1 Verify Repairs" .
   2. If the voltage is less than 2.5 volts, go to step 5 .
5. Measure the voltage between pin 2 of the Engine Oil Pressure Switch/Sensor harness connector and ground.
   1. If the voltage is between 2.5 and 3 volts, repair the open circuit between pin 1 of the Engine Oil Pressure Switch/Sensor harness connector and pin 55 of the 120–pin MCM connector. Refer to "27.3.1.1 Verify Repairs" .
   2. If the voltage is less than 2.5 volts, repair the open circuit between pin 2 of the Engine Oil Pressure Switch/Sensor harness connector and pin 54 of the 120–pin MCM connector. Refer to "27.3.1.1 Verify Repairs" .

Section 27.3.1.1
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.