RAM 3500 HD Truck 4WD L6-6.7L DSL Turbo VIN A (2007)
Oxygen Sensor: Description and Operation
Operation - Pick Up Models
OPERATION - PICK UP MODELS
Two different six-wire O2 sensors are used. These sensors are titled 1/1 upstream (1), and 1/2 downstream (2).
A separate O2 Sensor Module (1) is also used.
The engine aftertreatment system monitors the O2 content in the diesel engine exhaust. The ECM monitors the exhaust gases for oxygen content and
varies the rich/lean fuel mixture of the intake air fuel mixture to adjust the system. This diagnostic monitors the status message broadcast by the O2
Sensor Module (1) for the upstream O2 sensor's internal heater circuit. The ECM will set the fault if it receives a FMI (Failure Mode Indicator) message
from the O2 Sensor Module. The ECM will illuminate the MIL lamp immediately when the diagnostic runs and fails. The ECM will turn off the MIL
lamp diagnostic runs and passes in four consecutive drive cycles.
