Spn 625/Fmi 9; Data Link Check - Detroit Diesel EPA07 Series 60 DDEC VI Troubleshooting Manual

52.2 SPN 625/FMI 9

This fault is typically erratic data or the CAN propriety data link has failed due to no
communication between the MCM and the CPC.
NOTE:
The following diagnostics pertain to faults received from the MCM and /or the CPC.
52.2.1

Data Link Check

Check as follows:
1. Have the MCM and/or the CPC been recently changed or reprogrammed?
[a] 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, go to the next step.
[b] If no, go to the next step.
2. Disconnect the MCM 21–pin connector.
3. Turn the ignition ON (key ON, engine OFF).
4. Measure the ignition voltage at pin 7 on the MCM 21–pin connector.
[a] If the ignition voltage is less than 10.5 volts, restore the ignition voltage at pin 7.
Refer to section 52.2.1.1.
[b] If the ignition voltage is greater than 10.5 volts, go to the next step.
5. Measure the battery voltage at pins 11, 12, 14, and 15 on the MCM 21–pin connector.
[a] If the battery voltage is less than 10.5 volts, restore the battery voltage at pins 11, 12,
14, and 15 on the MCM 21–pin connector.
NOTE:
Poor battery grounds can be a possible cause of low battery voltage.
[b] If the battery voltage is greater than 10.5 volts, go to the next step.
6. Turn ignition OFF, leave the 21–pin MCM connector disconnected.
7. Disconnect the CPC #4 connector.
8. Measure the resistance between pins 1 and 3 of the CPC #4 connector.
[a] If the resistance is greater than 5 Ω, go to the next step.
[b] 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 section 52.2.1.1.
9. Measure the resistance between pin 1 of the CPC #4 connector and ground.
[a] If the resistance is greater than 5 Ω, go to the next step.
All information subject to change without notice.
Copyright © 2007 DETROIT DIESEL CORPORATION
SERIES 60 DDEC VI TROUBLESHOOTING GUIDE
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