This Service Information bulletin supersedes SI 12 33 14 dated December 2015. SUBJECT Fault Code 1D2008 Stored in DME. The Service Engine Soon light is on. Fault Code 1D2008: Map thermostat: jammed open is stored in the DME. There may also be a complaint of low heat output with lower outside temperatures. CAUSE During the engine warm-up, the engine coolant does not reach operating temperature within the DME's allowable time limits. This is caused by either a faulty thermostat inside the transmission oil heat exchanger or a faulty engine characteristic map thermostat.