NVG 136 Transfer Case

CIRCUIT DESCRIPTION
At each power up the module runs a self test on the following:
- Electrically Erasable Programmable Read Only Memory (EEPROM) Checksum
- ROM Checksum
- RAM Checksum
- RAM Malfunction
- Relay Malfunction

CONDITIONS FOR SETTING THE DTC
- Critical operational parameters stored in Electrically Erasable Programmable Read Only Memory (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- Masked ROM code has failed checksum test indicating that masked ROM data is no longer valid.
- ROM code has failed checksum test indicating that ROM data is no longer valid.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 the module's relay is not able to make contact.

ACTION TAKEN WHEN THE DTC SETS
The SERVICE AWD/4WD lamp will be latched on and the system will be disabled.

CONDITIONS FOR CLEARING THE MIL/DTC
- Replace the transfer case shift control module.
- Perform the Transfer Case Diagnostic System Check.