Transfer Case
DTC C0550Circuit Description
At each power-up the transfer case shift control module runs a self-test on the following functions:
^ EEPROM Checksum
^ ROM Checksum
^ RAM Checksum
^ RAM Malfunction
Conditions for Setting the DTC
^ Critical operational parameters stored in EEPROM have failed Checksum test indicating invalid data.
^ Masked ROM code has failed Checksum test indicating that masked ROM data is not currently valid.
^ ROM code has failed Checksum test indicating that ROM data is not currently valid.
^ One or more ROM locations have failed operational test indicating that some portions of RAM are not functional.
Action Taken When the DTC Sets
^ The SERVICE 4WD indicator will be latched on and the system will be disabled.
^ The transfer case control switch will not display the current position LED while DTC C0550 is current.
Conditions for Clearing the DTC
^ Replace the transfer case shift control module.
^ Perform the Transfer Case Diagnostic System Check.
Test Description
The number below refers to the step number on the diagnostic table
2. Replacement of the transfer case shift control module.
DTC C0550 (1 Of 2):
