C0550

Circuit Description
At each power up the module runs a self test on the following:
^ EEPROM Checksum
^ ROM Checksum
^ RAM Checksum
^ RAM Malfunction
^ Relay 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^ Masked ROM code has failed checksum test indicating that masked ROM data is no longer valid.
^ ROM code has failed checksum test indicating that ROM data is no longer valid.
^ One or more RAM locations have failed operational test indicating that some portions of RAM are not functional.
^ Motor circuit test has indicated that one of the module's relays is not able to make contact.


Action Taken When the DTC Sets
The SERVICE indicator (4WD/AWD) lamp will be latched on and the system will be disabled.


Conditions for Clearing the DTC
^ Replace the Auto transfer Case Control Module.
^ Perform the Auto transfer Case System Check.