Section 57.2
SPN 641/FMI 8

This code typically means the Smart Remote Actuator 5 has an internal test running.‪

Section 57.2.1
Actuator Check

Check as follows:‪

1. Disconnect the turbo actuator.
2. Disconnect the MCM 120–pin connector.
3. Measure the resistance between pin 3 of the turbo actuator harness connector and pin 74 of the MCM 120–pin connector.
   1. If the resistance is less than 3 Ω, go to step 4 .
   2. If the resistance is greater than 3 Ω, repair the open between pin 3 of the turbo actuator harness connector and pin 74 of the MCM 120–pin connector. Refer to "57.2.1.1 Verify Repairs" .
4. Measure the resistance between pin 4 of the turbo actuator harness connector and pin 75 of the MCM 120–pin connector.
   1. If the resistance is less than 3 Ω, replace the turbo actuator. Refer to "57.2.1.1 Verify Repairs" .
   2. If the resistance is greater than 3 Ω, repair the open between pin 4 of the turbo actuator harness connector and pin 75 of the MCM 120–pin connector. Refer to "57.2.1.1 Verify Repairs" .

Section 57.2.1.1
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.