MBE 4000 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 Sensor short-to-power fault. ‪

Section 27.3.1
Short to Power Check

Check as follows:‪

1. Turn the ignition ON (key ON, engine OFF).
2. Check for multiple codes.
   1. If 100/3, 175/3, 1172/3 and 1176/3 are present, repair the open between pin 105 of the 120–pin connector and the associated sensors. Refer to "27.3.1.1 Verify Repairs" .
   2. If 100/3 and 175/3 are present, go to step 7 .
   3. If only 100/3 is present, go to step 2 .
3. Turn the ignition OFF.
4. Disconnect the Engine Oil Pressure/Temp Sensor.
5. Disconnect the 120–pin MCM connector.
6. Measure the resistance between pins 3 and 4 of the combination sensor harness connector.
   1. If resistance is less than 5 Ω, repair short circuit between 120-pin MCM connector wires 54 and 82. Refer to "27.3.1.1 Verify Repairs" .
   2. If resistance is greater than 5 Ω, repair the short to power on the circuit between pin 54 of the 120–pin MCM connector and pin 4 of the Engine Oil Pressure/Temp Sensor harness connector. See Figure "Engine Oil Pressure/Temp Sensor" . Refer to "27.3.1.1 Verify Repairs" .
7. Disconnect the Engine Oil Pressure/Temp Sensor.
8. Measure the resistance between pin 1 and 3 of the Engine Oil Pressure/Temp Sensor.
   1. If resistance is less than 140 Ω, go to step 9 .
   2. If resistance is greater than 140 Ω, replace the sensor. Refer to "27.3.1.1 Verify Repairs" .
9. Turn the ignition ON (key ON, engine OFF).
10. Measure the voltage between pin 3 of the combination sensor and ground.
    1. If the voltage is less than 2.75 volts, repair the open circuit between pin 82 of the 120–pin MCM connector and pin 3 of the Engine Oil Pressure/Temp Sensor. See Figure "Engine Oil Pressure/Temp Sensor" . Refer to "27.3.1.1 Verify Repairs" .
    

    Figure 1. Engine Oil Pressure/Temp Sensor

    2. If the voltage is less than 2.75 volts, repair the open circuit between pin 105 of the 120–pin MCM connector and pin 1 of the Engine Oil Pressure/Temp Sensor. See Figure "Engine Oil Pressure/Temp Sensor" . 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.