MBE 4000 DDEC VI Troubleshooting – Section 81.1 SPN 1073/FMI 3

Section 81.1
SPN 1073/FMI 3

This diagnosis is typically a short to power.‪

Section 81.1.1
Short to Power Check

Check as follows:‪

1. Disconnect the Brake Gate solenoid.
2. Turn the ignition ON (key ON, engine OFF).
3. Measure the voltage between pin 1 of the Brake Gate harness connector and ground.
   1. If the voltage is greater than 11.5 volts, repair the short to power between pin 1 of the Brake Gate harness connector and pin 96 of the 120–pin MCM connector. See Figure "Brake Gate" . Refer to "81.1.1.1 Verify Repairs" .
   

   Figure 1. Brake Gate

   2. If the voltage is less than 11.5 volts, go to step 4 .
4. Turn the ignition OFF.
5. Disconnect the 120–pin MCM connector.
6. Measure the resistance between pins 1 and 2 of the Brake Gate harness connector.
   1. If the resistance is greater than 5Ω, reconnect the 120–pin MCM connector and repeat steps 2 through 6 . If the results are the same, contact the Detroit Diesel Customer Support Center (313–592–5800).
   2. If the resistance is less than 5Ω, repair the short between pins 1 and 2 of the Brake Gate harness connector and pins 91 and 96 of the 120–pin MCM connector. Refer to "81.1.1.1 Verify Repairs" .

Section 81.1.1.1
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.