MBE 4000 DDEC VI Troubleshooting – Section 81.3 SPN 1073/FMI 5

Section 81.3
SPN 1073/FMI 5

This diagnosis is typically the Brake Gate solenoid circuit failed open.‪

Section 81.3.1
Open Circuit 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 2 of the Brake Gate harness connector and ground.
   1. If the voltage is less than 11.5 volts, replace the open between pin 2 of the Brake Gate harness connector and pin 91 of the MCM 120–pin connector. See Figure "Brake Gate" . Refer to "81.3.1.1 Verify Repairs" .
   

   Figure 1. Brake Gate

   2. If the voltage is greater than 11.5 volts, go to step 4 .
4. Measure the resistance across the Brake Gate.
   1. If the resistance is greater than 15 Ω, replace the Brake Gate. Refer to "81.3.1.1 Verify Repairs" .
   2. If the resistance is less than 15 Ω, repair the open between pin 1 of the Brake Gate harness connector and pin 96 of the MCM 120–pin connector. Refer to "81.3.1.1 Verify Repairs" .

Section 81.3.1.1
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.