MBE 900 DDEC VI Troubleshooting – Section 84.3 SPN 1188/FMI 9

Section 84.3
SPN 1188/FMI 9

This code typically means the wastegate actuator is in Failsafe Mode, Motor Off.‪

Section 84.3.1
Actuator Check

Check as follows:‪

1. Disconnect the wastegate actuator.
2. Inspect the wastegate actuator connector and harness for damaged, bent or spread pins.
   1. If damage is found, repair as necessary. Refer to "84.3.1.1 Verify Repairs" .
   2. If no damage is found, go to the next step.
3. Disconnect the MCM 120–pin connector.
4. Measure the resistance between pin 3 of the wastegate actuator harness connector and pin 74 of the MCM 120–pin connector.
   1. If the resistance is greater than 3 Ω, repair the open circuit between pin 3 of the wastegate actuator harness connector and pin 74 of the MCM 120–pin connector. Refer to "84.3.1.1 Verify Repairs" .
   2. If the resistance is less than 3 Ω, go to the next step.
5. Measure the resistance between pin 4 of the wastegate actuator harness connector and pin 75 of the MCM 120–pin connector.
   1. If the resistance is greater than 3 Ω, repair the open circuit between pin 4 of the wastegate actuator harness connector and pin 75 of the MCM 120–pin connector. Refer to "84.3.1.1 Verify Repairs" .
   2. If the resistance is less than 3 Ω, replace the wastegate actuator. Refer to "84.3.1.1 Verify Repairs" .

Section 84.3.1.1
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.