MBE 900 DDEC VI Troubleshooting – Section 35.2 SPN 175/FMI 3

Section 35.2
SPN 175/FMI 3

‪

This diagnosis is typically engine oil temperature short to power.‪

Section 35.2.1
Check for Open Short to Power

Check as follows:‪

1. Check for multiple codes..
   1. If codes 110/3, 174/3 and 175/3 are active at the same time, repair the open between pin 55 of the 120–pin MCM connector and associated sensors. Refer to "35.2.1.1 Verify Repairs" .
   2. If only fault 175/3 is active, go to step 2 .
2. Disconnect the Engine Oil Temperature Sensor. See Figure "Engine Oil Temperature Sensor" .
   

   Figure 1. Engine Oil Temperature Sensor

3. Measure the resistance between pins 1 and 2 of the Engine Oil Temperature Sensor.
   1. If the resistance is greater than 4k Ω, replace the Engine Oil Temperature Sensor. Refer to "35.2.1.1 Verify Repairs" .
   2. If he resistance is less than 4k Ω, go to step 4 .
4. Turn the ignition ON (key ON, engine OFF).
5. Measure the voltage between pins 1 and 2 of the Engine Oil Temperature Sensor harness connector.
   1. If the voltage is between 2.5 and 3 volts, refer to "35.2.1.1 Verify Repairs" .
   2. If the voltage is less than 2.5 volts, go to step 6 .
6. Measure the voltage between pin 2 of the Engine Oil Temperature Sensor harness connector and ground.
   1. If the voltage is between 2.5 and 3 volts, repair the open circuit between pin 55 of the 120–pin MCM connector and pin 1 of the Engine Oil Temperature Sensor harness connector. Refer to "35.2.1.1 Verify Repairs" .
   2. If the voltage is less than 2.5 volts, repair the open circuit between pin 108 of the 120–pin MCM connector and pin 2 of the Engine Oil Temperature Sensor harness connector. Refer to "35.2.1.1 Verify Repairs" .

Section 35.2.1.1
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.