MBE 900 DDEC VI Troubleshooting – Section 35.3 SPN 175/FMI 4

Section 35.3
SPN 175/FMI 4

This diagnosis is typically oil temperature sensor open short to ground.‪

Section 35.3.1
Check for Short to Ground

Check as follows:‪

1. Disconnect the Engine Oil Temperature Sensor.
2. Disconnect the 120–pin MCM connector.
3. Measure the resistance between pins 1 and 2 of the Engine Oil Temperature Sensor connector. See Figure "Engine Oil Temperature Sensor" .
   

   Figure 1. Engine Oil Temperature Sensor

   1. If the resistance is greater than 5Ω, go to step 4 .
   2. If the resistance is less than 5Ω, repair the short between pins 55 and 108 of 120–pin MCM connector. See Figure "120–pin MCM Connector" . Refer to "35.3.1.1 Verify Repairs" .
   

   Figure 2. 120–pin MCM Connector

4. Measure the resistance between pin 1 of the Engine Oil Temperature Sensor connector and ground.
   1. If the resistance is greater than 5Ω, go to step 5 .
   2. If the resistance is less than 5Ω, repair the short circuit between pin 1 of the Engine Oil Temperature Sensor connector and chassis ground. Refer to "35.3.1.1 Verify Repairs" .
5. Measure the resistance between pin 2 of the Engine Oil Temperature Sensor connector and ground.
   1. If the resistance is greater than 5Ω, repeat steps 3 through 5 . If the results are the same, call the Detroit Diesel Customer Support Center (313–592–5800).
   2. If the resistance is less than 5Ω, repair the short circuit between pin 2 of the Engine Oil Temperature Sensor harness connector and ground. Refer to "35.3.1.1 Verify Repairs" .

Section 35.3.1.1
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.