U0025-CAN B BUS (-) CIRCUIT LOW





For a complete wiring diagram Refer to Section 8W.


  • When Monitored:

    Continuously

  • Set Condition:

    The FCM detects the (D54) CAN B Bus (-) circuit is shorted to ground.


Possible Causes
  
(D54) CAN B BUS (-) CIRCUIT SHORTED TO GROUND OR TO (D55) CAN B BUS (+) CIRCUIT
  
ANY CAN B BUS MODULE
  
FRONT CONTROL MODULE
  



Diagnostic Test

1.TEST FOR INTERMITTENT CONDITION







Does the scan tool display this DTC as active?

Yes
  • Go To 2


No
  • The conditions that caused this code to set are not present at this time. Using the wiring diagram/schematic as a guide, inspect the wiring and connectors.

2.CHECK THE (D54) CAN B BUS (-) CIRCUIT FOR A SHORT TO GROUND







Is resistance below 1000.0 ohms?

Yes
  • Go To 3


No
  • Go To 4

3.(D54) CAN B BUS (-) CIRCUIT SHORTED TO GROUND





NOTE: This is to determine if the short to ground is internal within a module or if the circuit is shorted.


NOTE: Disconnecting an in-line connector can eliminate a module or group of modules from the list of possible causes for this fault. Refer to the wiring diagrams to assist in diagnosis.



Is resistance below 1000.0 ohms with all the CAN B Bus modules disconnected?

Yes


No

4.CHECK THE (D55) CAN B BUS (+) CIRCUIT FOR A SHORT TO THE (D54) CAN B BUS (-) CIRCUIT





Is resistance below 1000.0 ohms?

Yes
  • Go To 5


No

5. (D55) CAN B BUS (+) CIRCUIT SHORTED TO THE (D54) CAN B BUS (-) CIRCUIT





NOTE: This is to determine if the short together is internal within a module or if the circuits are shorted together.


NOTE: Disconnecting an in-line connector can eliminate a module or group of modules from the list of possible causes for this fault. Refer to the wiring diagrams to assist in diagnosis.



Is resistance below 1000.0 ohms with all the CAN B Bus modules disconnected?

Yes


No