MBE 900 DDEC VI Troubleshooting – Section 50.1 SPN 615/FMI 7

Section 50.1
SPN 615/FMI 7

This code typically means the exhaust flap actuator is in Failsafe Mode, Motor On.‪

Section 50.1.1
Actuator Check

Check as follows:‪

1. Physically move the exhaust flap actuator rod from stop to stop to check for unrestricted movement.
   1. If unrestricted movement is felt, go to step 4 .
   2. If the actuator rod does not move from stop to stop, go to the next step.
2. Disconnect the exhaust flap actuator rod.
3. Physically move the exhaust flap butterfly from stop to stop to check for unrestricted movement.
   1. If the exhaust flap butterfly does not move stop to stop, replace the exhaust flap valve.
   2. If the exhaust flap butterfly does move stop to stop, replace the exhaust flap actuator.
4. Disconnect the exhaust flap actuator harness connector.
5. Turn the ignition ON (key ON, engine OFF).
6. Measure the voltage between pins 1 and 2 of the exhaust flap control actuator connector.
   1. If the voltage is greater than 11 volts, go to step 8 .
   2. If the voltage is less than 11 volts, go to the next step.
7. Measure the voltage between pin 1 of the exhaust flap control actuator connector and ground.
   1. If the voltage is less than 11 volts, repair the open between pin 1 of the exhaust flap control actuator connector and pin 93 of the MCM 120–pin connector. Refer to "50.1.1.1 Verify Repairs" .
   2. If the voltage is greater than 11 volts, repair the open between pin 2 of the exhaust flap control actuator connector and pin 38 of the MCM 120–pin connector. Refer to "50.1.1.1 Verify Repairs" .
8. Turn the ignition OFF.
9. Disconnect the MCM 120–pin connector.
10. Measure the resistance between pin 3 of the exhaust flap control actuator connector and pin 74 of the MCM 120–pin connector.
    1. If the resistance is greater than 3 Ω, repair the open between pin 3 of the exhaust flap control actuator connector and pin 74 of the MCM 120–pin connector. Refer to "50.1.1.1 Verify Repairs" .
    2. If the resistance is less than 3 Ω, go to the next step.
11. Measure the resistance between pin 4 of the exhaust flap control actuator connector and pin 75 of the MCM 120–pin connector.
    1. If the resistance is greater than 3 Ω, repair the open between pin 4 of the exhaust flap control actuator connector and pin 75 of the MCM 120–pin connector. Refer to "50.1.1.1 Verify Repairs" .
    2. If the resistance is less than 3 Ω, replace the exhaust flap control actuator. Refer to "50.1.1.1 Verify Repairs" .

Section 50.1.1.1
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.