MBE 4000 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

Perform the following steps to troubleshoot an ECT Sensor short-to-ground fault.‪

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

   Figure 1. Engine Coolant Temperature Sensor

   1. If resistance is greater than 5 Ω, replace the ECT Sensor. Refer to "29.4.1.1 Verify Repairs" .
   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.