MBE 900 DDEC VI Troubleshooting – Section 96.2 SPN 2629/FMI 4

Section 96.2
SPN 2629/FMI 4

This condition is typically a short circuit.‪

Section 96.2.1
Short Circuit Check

Check as follows:‪

1. Disconnect the TCO Sensor.
2. Disconnect the 120–pin MCM connector.
3. Measure the resistance between the 120–pin MCM connector wire 50 and 112.
   1. If the resistance is less than 5k Ω, repair the short between the 120–pin MCM connector wire 50 and 112. Refer to "96.2.1.1 Verify Repairs" .
   2. If the resistance is greater than 5k Ω, go to step 4 .
4. Measure the resistance between pin 1 of the TCO Sensor connector and ground. See Figure "TCO Sensor" .
   

   Figure 1. TCO Sensor

   1. If the resistance is less than 5k Ω, repair the short circuit between pin 1 of the TCO Sensor connector and ground. Refer to "96.2.1.1 Verify Repairs" .
   2. If the resistance is greater than 5k Ω, go to step 5 .
5. Measure the resistance between pin 2 of the TCO Sensor connector and ground.
   1. If the resistance is less than 5k Ω, repair the short circuit between pin 2 of the TCO Sensor connector and ground. Refer to "96.2.1.1 Verify Repairs" .
   2. If the resistance is greater than 5k Ω, contact the Detroit Diesel Customer Support Center (313–592–5800) for authorization to replace the MCM.

Section 96.2.1.1
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.