Series 60 DDEC V Troubleshooting

Section 58.2 Troubleshooting Flash Code 56, SID 250/Fmi12

Section 58.2
Troubleshooting Flash Code 56, SID 250/Fmi12

This diagnostic condition is typically:‪

  • Either or both of the data link circuits are open at some point in the network.
  • Either or both of the data link circuits are shorted to ground at some point in the network.
  • Either or both of the data link circuits are shorted to battery (+) at some point in the network.
  • The pair of data link circuits are shorted together.

The following procedure will troubleshoot Flash Code 56.‪

Section 58.2.1
Multiple Code Check

Perform the following steps to check for multiple codes.‪

  1. Turn vehicle ignition switch ON.
  2. Plug in the diagnostic tool.
  3. Read active codes.
    1. If codes other than 250/12 are logged, service them first.
    2. If code 250/12 is logged, and no other codes are logged, Refer to "58.2.2 Clear Codes" .
    3. If no data is logged, refer to "18.3 First Step for Diagnosing a Fault Within the DDEC System" .

Section 58.2.2
Clear Codes

Perform the following steps to clear codes.‪

  1. Clear codes.
  2. Start and run the engine.
  3. Observe CEL/AWL/code.
    1. If CEL/AWL is on with code 250/12 logged, refer to "58.2.3 Check for Devices of Original Equipment Manufacturer" .
    2. If no CEL/AWL code is logged, refer to "58.2.4.1 Verify Repairs" .

Section 58.2.3
Check for Devices of Original Equipment Manufacturer

Perform the following steps to check for OEM devices.‪

  1. Turn vehicle ignition OFF.
  2. Determine if any OEM equipment utilizes the J1587 data link. (ABS, ProDriver®, satellite systems, etc.).
    1. If any OEM devices are installed, refer to "58.2.4 Disconnect Nodes (Data Link Devices)" , step 1 .
    2. If no OEM devices are installed, refer to "58.2.4 Disconnect Nodes (Data Link Devices)" , step 2 .

Section 58.2.4
Disconnect Nodes (Data Link Devices)

Perform the following steps to disconnect the nodes.‪

  1. Disconnect OEM installed devices, one at a time e.g. ABS, satellite systems, etc. Verify ABS switch is not in "Test" mode.
    1. If the disconnect does not solve the problem, continue the procedure.
    2. If the disconnect solved the problem, go to .
  2. Connect vehicle interface module, J 41005.
  3. Start and run the engine.
  4. Observe CEL/AWL codes.
    1. If CEL/AWL or codes displayed, and the CEL/AWL is on with code 250/12 logged, replace the ECM/ECU with a test ECM/ECU. Refer to "58.2.4.1 Verify Repairs" .
    2. If no CEL/AWL or codes are displayed, contact OEM for instructions on how to proceed. Refer to "58.2.4.1 Verify Repairs" .
Section 58.2.4.1
Verify Repairs

Perform the following steps to verify repairs.‪

  1. Turn vehicle ignition OFF.
  2. Reconnect all connectors.
  3. Start and run the engine.
    1. If the CEL/AWL or codes are displayed, and if code 250/12 is logged, all system diagnostics are complete. Review this section to find the error.
    2. If the CEL/AWL or codes are not displayed, troubleshooting is complete.


Series 60 DDEC V Troubleshooting Guide - 6SE570
Generated on 10-13-2008

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