MBE 900 DDEC VI Troubleshooting – Section 29.4 SPN 110/FMI 4

Section 29.4
SPN 110/FMI 4

The diagnostic condition is typically engine coolant temperature short to ground.‪

Section 29.4.1
Short to Ground Check

Check as follows:‪

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

   Figure 1. Engine Coolant Temperature Sensor

   1. If resistance is greater than 5 Ω, go to step 4 .
   2. If resistance is less than 5 Ω, repair short to ground between pins 73 and 110 of the 120-pin MCM connector. Refer to "29.4.1.1 Verify Repairs" .
4. Measure the resistance between pin 1 of the ECT Sensor harness connector and ground.
   1. If resistance is greater than 5 Ω, go to step 5 .
   2. If resistance is less than 5 Ω, repair the short circuit pin 1 of the ECT Sensor harness connector and ground. Refer to "29.4.1.1 Verify Repairs" .
5. Measure the resistance between pin 2 of the ECT Sensor harness connector and ground.
   1. If resistance is greater than 5 Ω, repeat steps 3 through 5 . If the results are the same, call the Detroit Diesel Customer Support Center (313–592–5800).
   2. If resistance is less than 5 Ω, repair the short circuit between pin 2 of the ECT Sensor harness connector and ground. Refer to "29.4.1.1 Verify Repairs" .

Section 29.4.1.1
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.