MBE 900 DDEC VI Troubleshooting – Section 59.2 SPN 654/FMI 14

Section 59.2
SPN 654/FMI 14

This diagnosis is typically an open circuit, short to ground or short to power.‪

Section 59.2.1
Open Circuit, Short to Ground or Short to Power Check

Check as follows:‪

1. Check for multiple codes.
   1. If 654/14, 655/14 and 656/14 are present, go to step 2 .
   2. If only 654/14 is present, go to step 6 .
2. Turn the ignition OFF.
3. Disconnect the MCM 120–pin connector (if using the J-48475 breakout box and appropriate overlay, only hook-up the MCM side connector).
4. Turn the ignition ON (key ON, engine OFF).
5. Measure the voltage between pin 17 of the MCM 120–pin connector and ground. See Figure "MBE 900 Injectors" .
   1. If voltage is present, contact the Detroit Diesel Customer Support Center at 313–592–5800.
   2. If no voltage is present, repair the short to power between pins 17, 19 or 21 of the MCM 120–pin connector and injector #4, #5 or #6. Refer to "59.2.1.1 Verify Repairs" .
   

   Figure 1. MBE 900 Injectors

6. Turn the ignition OFF.
7. Disconnect the 12–pin injector valve cover harness.
8. Measure the resistance between pins 1 and 2 on the valve cover side of the injector harness. If you are using the J-48671 breakout box, measure between pins 1 and 2 of injector #4.
   1. If the resistance is greater than 3 Ω, go to step 9 .
   2. If the resistance is less than 3 Ω, go to step 11 .
9. Remove the valve cover
10. Measure the resistance across injector #4.
    1. If the resistance is greater than 3 Ω, replace the injector. Refer to "59.2.1.1 Verify Repairs" .
    2. If the resistance is less than 3 Ω, replace the valve cover injector harness. Refer to "59.2.1.1 Verify Repairs" .
11. Disconnect the MCM 120–pin connector.
12. Measure the resistance between pin 8 on the engine side of the 12–pin injector valve cover harness connector and pin 17 of the MCM 120–pin connector.
    1. If the resistance is greater than 3 Ω, repair the open circuit between pin 8 on the engine side of the 12–pin injector valve cover harness connector and pin 17 of the MCM 120–pin connector. Refer to "59.2.1.1 Verify Repairs" .
    2. If the resistance is less than 3 Ω, repair the open circuit between pin 7 on the engine side of the 12–pin injector valve cover harness connector and pin 16 of the MCM 120–pin connector. Refer to "59.2.1.1 Verify Repairs" .

Section 59.2.1.1
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.