Diagnostic Trouble Code (DTC) Information TCM-0049

Condition 

Fig 1: Identifying Transmission Control Module (TCM)

Courtesy of VOLVO CARS CORPORATION

The transmission control module (TCM) has two different internal memories, one for permanent storage of information (EEPROM memory) and one for temporary information (FLASH memory). The information in the temporary memory is saved down to the permanent memory every time the ignition is switched off. When the temporary information is saved to the permanent memory, the information is checked against that which is already stored. The diagnostic trouble code (DTC) is stored if the transmission control module (TCM) discovers that the stored information does not correspond to the information in the control module FLASH memory.

Substitute Value 

• Emergency program Emergency mode 4 in the transmission control module (TCM) has been initiated.

  HINT:  EMERGENCY MODE IN THE EVENT OF A FAULT 

Possible Source 

• Faulty software in the transmission control module (TCM)
• Internal fault in the transmission control module (TCM).

Fault symptom[s] 

• Malfunction indicator lamp (MIL) lit
• General warning lamp lit
• Harsh gear shifting
• No shifting.