DD15 SPN 4076/FMI 3 Troubleshooting

SPN 4076/FMI 3

This code indicates the SPN 4076/FMI 3 has failed high.‪

Check as follows:‪

1. Check for multiple codes.
   1. If 110/3, 174/3, 175/3 and 4076/3 are present, go to step 6 .
   2. If only 4076/3 is present, go to the next step.
2. Disconnect the Engine Coolant Inlet Temperature Sensor.
3. Turn the ignition On (key ON, engine OFF).
4. Measure the voltage between pins 1 and 2 of the Engine Coolant Inlet Temperature Sensor harness connector.
   1. If the voltage is between 2.8 and 3 volts, replace the Engine Coolant Inlet Temperature Sensor. Refer to “130.1.1 Verify Repairs” .
   2. If the voltage is less than 2.8 volts, go to the next step.
5. Measure voltage between pin 2 of the Engine Coolant Inlet Temperature Sensor and ground.
   1. If the voltage is between 2.8 and 3 volts, repair the wire between pin 1 of the Engine Coolant Inlet Temperature Sensor connector and pin 80 of the MCM 120–pin connector. Refer to “130.1.1 Verify Repairs” .
   2. If the voltage is less than 2.8 volts, repair the wire between pin 2 of the Engine Coolant Inlet Temperature Sensor connector and pin 55 of the MCM 120–pin connector. Refer to “130.1.1 Verify Repairs” .
6. Measure the voltage between pins 1 and 2 of the Engine Coolant Inlet Temperature Sensor harness connector.
   1. If the voltage is greater than 3 volts, repair the short to power on one of the follwoing MCM pins: 77, 80, 108 or 110. Refer to “130.1.1 Verify Repairs” .
   2. If no voltage is present, repair the open between pin 55 of the MCM 120–pin connector and the Coolant Out, Coolant In, Engine Oil and Supply Fuel Temperature Sensors. Refer to “130.1.1 Verify Repairs” .

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.
   

   ENGINE EXHAUST ‪
   To avoid injury from inhaling engine exhaust, always operate the engine in a well-ventilated area. Engine exhaust is toxic.‪

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.