MBE 900 DDEC VI Troubleshooting – Section 81.2 SPN 1073/FMI 4

Section 81.2
SPN 1073/FMI 4

This diagnosis is typically a short to ground.‪

Section 81.2.1
Short to Ground Check

Check as follows:‪

1. Disconnect the Exhaust Flap solenoid.
2. Disconnect the 120–pin MCM connector.
3. Measure the resistance between pins 1 and 2 of the Exhaust Flap harness connector.
   1. If the resistance is less than 5 Ω, repair the short between wires 91 and 96 of the 120–pin connector. Refer to "81.2.1.1 Verify Repairs" .
   2. If the resistance is greater than 5 Ω, go to step 4 .
4. Measure the resistance between pin 1 of the Exhaust Flap harness connector and ground.
   1. If the resistance is less than 5 Ω, repair the short between pin 1 of the Exhaust Flap harness connector and ground. Refer to "81.2.1.1 Verify Repairs" .
   2. If the resistance is greater than 5 Ω, replace the Exhaust Flap.

Section 81.2.1.1
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.