MBE 4000 DDEC VI Troubleshooting – Section 82.2 SPN 1172/Fmi3

Section 82.2
SPN 1172/Fmi3

This code is typically turbocharger compressor inlet temperature circuit failed high.‪

Section 82.2.1
Open Circuit Check

Check as follows:‪

1. Check for multiple codes.
   1. If 175/3, 100/3 and 1172/3 are present, repair the open between pin 105 of the MCM 120–pin connector and the Turbo Inlet and Engine Oil Pressure/Temperature sensors. Refer to "82.2.2.1 Verify Repairs" .
   2. If only 1172/3 is present, go to the next step.
2. Disconnect the Turbo Compressor In Temperature Sensor (TCI Sensor).
3. Turn the ignition ON (key ON, engine OFF).
4. Measure the voltage between pins 3 and pin 4 on the harness side of the TCI Sensor.
   1. If the voltage is greater than 4.5 volts, replace the sensor. Refer to "82.2.2.1 Verify Repairs" .
   2. If the voltage is less than 4.5 volts, go to the next step.
   

   Figure 1. Turbo Compressor In Temperature Sensor

5. Measure the voltage between pin 3 of the TCI Sensor and ground.
   1. If the voltage is greater than 4.5 volts, repair the open between pin 4 of the TCI Sensor and pin 105 of the MCM 120–pin connector.Refer to "82.2.2.1 Verify Repairs" .
   2. If the voltage is less than 4.5 volts, repair the open between pin 3 of the TCI Sensor and pin 86 of the MCM 120–pin connector. Refer to "82.2.2.1 Verify Repairs" .

Section 82.2.1.1
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.