This Preliminary Information communication provides information to the technician on how the radio display gets the air ambient temperature. On 1500 series trucks and all sport utility vehicle with regular production option code IO3 radio the ambient air temperature sensor is hard wired to the engine control module and then the signal goes on high speed local area network to the body control module from there on low speed local area network to the radio. On 1500 series trucks and all sport utility vehicle with regular production option code IO4, IO5, or IO6 the ambient air temperature sensor is hard wired to the engine control module and then the signal goes on high speed local area network to the body control module from there on low speed local area network to the radio then Most 50 Bus to the Human Machine Interface. On 2500/3500 series trucks production option code IO3 radio the ambient air temperature sensor is hard wired to the instrument panel cluster and then the signal goes on low speed local area network to the radio. On 2500/3500 series trucks production option code IO4, IO5, or IO6 radio the ambient air temperature sensor is hard wired to the instrument panel cluster and then the signal goes on low speed local area network to the radio then Most 50 Bus to the Human Machine Interface.
