DD15 SPN 625/FMI 2 Troubleshooting

SPN 625/FMI 2

This fault is typically erratic data or the CAN propriety data link has failed between the MCM and the CPC.‪

Note: The following diagnostics pertain to faults received from the MCM and /or the CPC.

Check as follows:‪

1. Have the MCM and/or the CPC have recently been changed or reprogrammed?
   1. If yes, verify the that the correct MCM calibration and/or the correct CPC parameter list has been installed. If the correct calibration and correct parameter list have been installed, then go to the next step.
   2. If the MCM and/or the CPC have not recently been changed or reprogrammed, go to the next step.
2. Disconnect the MCM 21–pin connector.
3. Turn the ignition ON (key ON, engine OFF).
4. Measure the battery voltage at pin 7 on the MCM 21–pin connector.
   1. 1. If the battery voltage is less than 10.5 volts, restore the battery voltage at pins 7, 11, 12, 14, and 15 on the MCM 21–pin connector.

   Note: Poor battery grounds can be a possible cause of low battery voltage.

   1. If the battery voltage is greater than 10.5 volts, go to the next step.
5. Turn ignition OFF, leave the 21–pin MCM connector disconnected.
6. Disconnect the CPC #4 connector.
7. Measure the resistance between pins 1 and 3 of the CPC #4 connector.
   1. If the resistance is greater than 5 Ω, go to the next step.
   2. If the resistance is less than 5 Ω, repair the short circuit in the wires between pins 1 and 3 of the CPC #4 connector and pins 13 and 19 of the 21–pin MCM connector. Refer to “52.1.1 Verify Repairs” .
8. Measure the resistance between pin 1 of the CPC #4 connector and ground.
   1. If the resistance is greater than 5 Ω, go to the next step.
   2. If the resistance is less than 5 Ω, repair the short circuit to ground between pin 1 of the CPC #4 connector and ground. Refer to “52.1.1 Verify Repairs” .
9. Check the resistance between pin 3 of the CPC #4 connector and ground.
   1. If the resistance is greater than 5 Ω, go to the next step.
   2. If the resistance is less than 5 Ω, repair the short circuit to ground between pin 3 of the CPC #4 connector and ground. Refer to “52.1.1 Verify Repairs” .
10. Measure the resistance between pin 1 of the CPC #4 connector and pin 19 of the 21–pin MCM connector.
    1. If the resistance is greater than 5 Ω, repair the open circuit between pin 1 of the CPC #4 connector and pin 19 of the 21–pin MCM connector. Refer to “52.1.1 Verify Repairs” .
    2. If the resistance is less than 5 Ω, go to the next step.
11. Measure the resistance between pin 3 of the CPC #4 connector and pin 13 of the 21–pin MCM connector.
    1. If the resistance is greater than 5 Ω, repair the open circuit between pin 3 of the CPC #4 connector and pin 13 of the 21–pin MCM connector. Refer to “52.1.1 Verify Repairs” .
    2. If the resistance is less than 5 Ω, call the DDC Customer Support Center (313–592–5800).

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.
   

   ENGINE EXHAUST ‪
   To avoid injury from inhaling engine exhaust, always operate the engine in a well-ventilated area. Engine exhaust is toxic.‪

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.