Series 60 DDEC VI Troubleshooting – Section 84.2 SPN 1172/FMI 3

Section 84.2
SPN 1172/FMI 3

This code is typically sensor or circuit failed high.‪

Section 84.2.1
Open Circuit Check

Check as follows:‪

1. Turn the ignition ON (key ON, engine OFF).
2. Check for multiple codes.
   1. If 1172/3, 3250/3, 3242/3 and 3246/3 are present, go to step 3 .
   2. If only 1172/3 is present, go to step 5
3. Disconnect the Turbo Compressor Inlet Temperature Sensor (TCI Sensor).
4. Measure the voltage between pin 1 of the TCI Sensor and ground.
   1. If the voltage is greater than 2.75 volts, repair the short to power between pin 88 of the 120–pin MCM connector and the TCI Sensor, DOC Inlet Temperature Sensor, DOC Outlet Temperature Sensor and the DPF Outlet Temperature Sensor. Refer to "84.2.1.1 Verify Repairs" .
   2. If no voltage is present on pin 1 of the Intake Air Temperature Sensor, repair the open between pin 88 of the 120–pin MCM connector and the TCI Sensor, DOC Inlet Temperature Sensor, DOC Outlet Temperature Sensor and the DPF Outlet Temperature Sensor. Refer to "84.2.1.1 Verify Repairs" .
5. Disconnect the Turbo Compressor Inlet Temperature Sensor.
6. Measure the voltage between pin 1 and pin 2 of the Turbo Compressor Inlet Temperature Sensor.
   1. If the voltage is less than 2.75 volts, go to step 7 .
   2. If the voltage is greater than 2.75 volts, replace the sensor. Refer to "84.2.1.1 Verify Repairs" .
7. Measure the voltage between pin 2 of the Turbo Compressor Inlet Temperature Sensor and ground.
   1. If the voltage is less than 2.75 volts, repair the open between pin 2 of the Turbo Compressor Inlet Temperature Sensor and pin 86 of the 120–pin MCM connector. Refer to "84.2.1.1 Verify Repairs" .
   2. If the voltage is greater than 2.75 volts, repair the open between pin 1 of the Turbo Compressor Inlet Temperature Sensor and pin 86 of the 120–pin MCM connector. Refer to "84.2.1.1 Verify Repairs" .

Section 84.2.1.1
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.